- Welcome to the Huberman Lab Podcast, where we discuss science and science-based tools for everyday life. I'm Andrew Huberman, and I'm a professor of neurobiology and ophthalmology at Stanford School of Medicine. My guest today is Dr. Teo Soleimani. Dr. Teo Soleimani is a double board certified dermatologist and dermatologic surgeon.

He did his training at Stanford University, and he was a clinical professor of dermatology and dermatologic surgery at UCLA. That is the University of California, Los Angeles. Today, we discuss all things related to skin appearance, skin health, and skin longevity. For instance, we discuss sun exposure and the impact it can have on both the appearance and health of one's skin.

In reference to that, we discuss sunscreens, which ones are safe, which ones perhaps elicit a bit more concern or perhaps should be avoided. And we discuss the surprising relationship between sun exposure and skin cancer. We discuss laser treatments for the skin, both for the appearance of skin in order to make it appear more youthful, as well as to prevent certain forms of skin cancer.

We discuss retinoids, we discuss supplements and nutrition, all in reference, again, to skin health and appearance. Thanks to Dr. Soleimani's incredible depth of expertise, as well as clarity of communication about the do's and do nots that relate to skin care and appearance and to avoiding and treating skin cancers, by the end of today's episode, you will be armed with an immense amount of knowledge that is the very latest in our understanding of how to improve and protect your skin.

Before we begin, I'd like to emphasize that this podcast is separate from my teaching and research roles at Stanford. It is, however, part of my desire and effort to bring zero cost to consumer information about science and science-related tools to the general public. In keeping with that theme, I'd like to thank the sponsors of today's podcast.

Our first sponsor is Roka. Roka makes eyeglasses and sunglasses that are of the absolute highest quality. I've spent a lifetime working on the biology of the visual system, and I can tell you that your visual system has to contend with an enormous number of different challenges in order for you to be able to see clearly from moment to moment.

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Now, even though Roka eyeglasses and sunglasses were initially designed for sport, they now have many different frames and styles, all of which can be used not just for sport, but also for wearing out to dinner, to work, essentially any time and any setting. I wear Roka readers at night or Roka eyeglasses if I'm driving at night, and I wear Roka sunglasses in the middle of the day anytime it's too bright for me to see clearly.

My eyes are somewhat sensitive, so I need that. I particularly like the Hunter 2.0 frames, which I have as eyeglasses and now as sunglasses too. If you'd like to try Roka, you can go to roka.com/huberman to get 20% off your purchase. Again, that's roka.com/huberman to get 20% off. Today's episode is also brought to us by Juve.

Juve makes medical grade red light therapy devices. Now, if there's one thing I've consistently emphasized on this podcast, it's the incredible impact that light can have on our biology. Now, in addition to sunlight, red light and near infrared light have been shown to have positive effects on improving numerous aspects of cellar and organ health, including faster muscle recovery, improved skin health and wound healing, even improvements in acne, reducing pain and inflammation, improving mitochondrial function, and even improving vision itself.

What sets Juve lights apart and why they're my preferred red light therapy devices is that they use clinically proven wavelengths, meaning it uses specific wavelengths of red light and near infrared light in combination to trigger the optimal cellar adaptations. Personally, I use the Juve handheld light both at home and when I travel.

It's only about the size of a sandwich, so it's super portable and convenient to use. I also have a Juve whole body panel, and I use that about three or four times per week. If you'd like to try Juve, you can go to juve, spelled J-O-O-V-V.com/huberman. Juve is offering an exclusive discount to all Huberman Loud listeners with up to $400 off select Juve products.

Again, that's Juve, J-O-O-V-V.com/huberman to get $400 off select Juve products. Today's episode is also brought to us by Helix Sleep. Helix Sleep makes mattresses and pillows that are customized to your unique sleep needs. I've spoken many times before on this and other podcasts about the fact that getting a great night's sleep is the foundation of mental health, physical health, and performance.

Now, the mattress we sleep on makes an enormous difference in terms of the quality of sleep that we get each night. We need a mattress that is matched to our unique sleep needs, one that is neither too soft nor too hard for you, one that breathes well and that won't be too warm or too cold for you.

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Either way, Helix will match you to the ideal mattress for you. For me, that turned out to be the Dusk mattress, D-U-S-K. I've been sleeping on a Dusk mattress for, gosh, no, more than four years. And the sleep that I've been getting is absolutely phenomenal. If you'd like to try Helix, you can go to helixsleep.com/huberman, take that brief two-minute sleep quiz, and Helix will match you to a mattress that is customized to your unique sleep needs.

Right now, Helix is giving up to 25% off mattresses and two free pillows. Again, that's helixsleep.com/huberman to get 25% off and two free pillows. And now for my discussion with Dr. Teo Soleimani. Dr. Teo Soleimani, welcome. - Thanks for having me. It's awesome to be here. Very, very privileged to be here, thank you.

- Oh, well, it's an honor to have you. Let's talk about this amazing organ we call skin. So skin, of course, covers our other organs. It's its own living biological entity. And just for sake of educational purposes and to frame the rest of what we're going to talk about, how much turnover is there in our skin?

Meaning the skin that I'm wearing right now, is that going to be 100%, 50% of the skin that I'm going to be wearing a year from now? I'm 49 years old, so. - Well, you look great for 49, so whatever you're doing, keep it up. So the skin's an amazing organ, just like you said.

It's the largest organ, the largest dynamic organ we have in our body. You have new skin, brand new skin, every 28 days. So the surface of your skin turns over about every month. Now the stem cells, which are in the lowest portion of our epidermis, remain and they generate the skin cells, but you have brand new skin the same way you have new gut lining every 28 days.

It's amazing for many reasons, because the skin is one of the few organs that can regenerate because of this. So you can grow new skin, you can test things on skin. If your skin gets injured, it will regenerate and heal itself. Whereas many other organs cannot do that. And because of this, it also allows us to use it as a model platform for studying diseases of all kinds.

So skin's an amazing organ. I mean, I guess I'm biased, but. - Well, I find a 28-day turnover just to be incredible. The skin, as I understand it, is innervated. That is, it receives connections from the nervous system. So I think for many people, their interest in skin is skin appearance, although we will also talk about skin health.

But in terms of skin appearance, how much does stress, short-term and longer-term stress, impact the appearance of our skin? And how does that work? I could imagine that the neurons release certain things into the skin. Does stress make our skin age faster? Does that mean it turns over more quickly or turns over more slowly?

Maybe you could link these two aspects of our biology for us. - Yeah, that's a great question. So in order to understand that, we have to just look at the structure of the skin. So the skin generally is three layers, the epidermis, the dermis, and the subcutaneous fat. And the dermis is where most of the biologic activity resides.

That's where our blood vessels are. That's where the nerves that innervate sensation and movement reside. That's where our hair follicles, oil glands, and sweat glands reside. So stress has two components. There's what we call acute stress, meaning stress that happens within a short period of time. And then there's long-term stress or chronic stress.

And both have different processes in the skin. And you see the results of stress both immediately in the skin with release of certain chemical messengers in an autocrine, paracrine, and holocrine fashion. And then you see the long-term deleterious effects of stress in a different mechanism in which there's actually breakdown of the skin.

The easiest way to see this is when people are stressed and they lose their hair. And the hair obviously is an extension of our skin. It's a biosensor of our wellbeing. And we see this all the time. You know, I see students during finals time where they're really stressed out and they're coming with their hair falling out.

Or after a large medical illness or a pregnancy, patients will come in and say their hair is falling out. So that acute stress is seen right away. And that's due to several different reasons and release of messengers and hormones and chemical mediators that do this. Long-term stress is usually mitigated or caused by cortisol.

And everybody knows cortisol. It's the fundamental stress hormone of our body. It falls in the same family as drugs that we give like prednisone. Falls in the same family of cholesterol, testosterone, and estrogen. But cortisol does something very different. It breaks things down to allow our body to utilize it in times of stress.

'Cause unfortunately, our body doesn't understand the difference between 21st century stress and old stress. So us being chased by a lion to our body's messaging system is the same as meeting chronic deadlines at work. And what happens is cortisol is responsible for the breakdown of things like collagen and elastin, thinning of vessel walls, which allow our skin to look supple and healthy.

So as we have a lot of stress and a lot of cortisol release, we see aging. And there's accelerated aging studies that look at patients and people who are under high periods of stress. A great example of studies, we look at presidents in which they appear to have aged much more rapidly than matched controls in a four-year period of time.

So stress plays a really important role. You see it both immediately and long-term. - I guess people rarely are sympathetic to presidents for aging quickly, because I guess if there were a president who did not age quickly, we would worry they did not work hard enough or something of that sort.

But the relationship between stress and skin fascinates me because not just of the direct relationship, like when we see people and they're stressed, like it seems like the power of their skin changes, the kind of level of gleam in their eyes change. And of course the eyes are a direct piece of the nervous system, really.

They're as close to the brain as one can get outside the skull. But it also suggests because of the dynamic turnover of skin every 28 days, that if people were to become less stressed that their skin health and appearance might improve. Is that also the case? - For sure.

It's why you see people have a glow after vacation, but you can't quantify that in a test tube or a lab. So in the immediate phase, there's a big shift in blood flow to the skin. And when you're feeling very stressed out, immediately there's a fight or flight response that constricts the blood vessels in our skin to shuffle them to muscles and places where our body thinks we need to utilize them more.

That's why when people are really stressed out, they may look pale or gaunt. And we see that right away. And then as that builds up over time, the health, the actual quality of our dermis and fat deteriorate from chronic stress changes, mainly due to cortisol and its sibling hormones and messaging systems in our skin.

So for sure, I mean, stress is like something that is impossible to quantify in a lab measure, but very easily seen on exam. Just looking at your skin, I can tell you've had either a rough day. If you didn't sleep well, you can see it in your skin, in your eyes.

So absolutely, I mean, that's why everybody likes to live a stress-free life. And we see changes and improvement in skin health when people move away from that stressor, whether it's a physical stressor, emotional stressor, psychosocial stressor, there is actual quantifiable improvements in skin health. And that's pretty fascinating. - It is fascinating.

It also speaks to the value of having some immediate and long-term stress reduction techniques, just as a sort of first principle of taking care of one's skin. There are some other things that cause vasoconstriction, the basically the tightening of the vessels and capillaries to the skin, as I understand.

Maybe we could just tick through a few of these and get your sense. I consume caffeine every morning, usually yerba mate tea, some coffee a little bit later. Those will increase vasoconstriction to some extent, although chronic caffeine intake may cause vasodilation. So I'd like to know the relationship between caffeine and blood flow to the skin and skin health and appearance.

That's the first question. And then dovetailed with that question is nicotine, which is also thought to be a vasoconstrictor. It raises blood pressure because it's a vasoconstrictor. What are the effects of caffeine, both acutely and chronically, and nicotine? Let's assume that nicotine is consumed either by smoking or oral ingestion on skin appearance and health.

- That's a good question. So caffeine is a known vasoconstrictor. Fortunately, when it's consumed in quantities that we have in coffee, tea, and equivalent beverages, the amount that affects the tiny capillaries and arterioles in our skin is minute and transient. So you may get a transient vasoconstriction with high caffeine intake, but usually there's a compensatory vasodilation as a result.

So the effects on skin are not as dramatic as people may make it seem. Now, one thing that we do see, and it's a little unclear as to why, is that people who have chronic high caffeine intake tend to produce more sebum in their skin. And it may be a result of vasoconstriction, may be a result of something that we don't understand that's compensatory as a result of those changes.

So a lot of people who consume coffee may experience a little bit oilier skin. That being said, the data's equivocal as to whether or not caffeine has a deleterious, beneficial, or net neutral effect on the skin. I drink a lot of coffee. I haven't found that the vasoconstriction is something that's noticeable, but there are people who have different skin types, patients who have rosacea, for example, who are much more sensitive to those changes.

They may notice that change in the color in the vasoconstriction more with caffeine consumption. What used to be thought was that caffeine itself was a problem for flushing and redness. And now we've realized it's actually not so much the caffeine because the concentration that reaches the skin is so minuscule.

It's actually the temperature of the beverages we drink. So hot beverages can affect the color of your skin, can make you flush more, make the redness more pronounced. Cold beverages tend not to have that effect. So it used to be an old adage in people who had like rosacea, for example, we'd say don't drink coffee, don't drink tea.

It's actually the temperature of the beverage, not so much the caffeine content. - Interesting, and what about nicotine? - So nicotine, great question. It is a known vasoconstrictor. Now, the concentration of nicotine when smoked is higher in the skin because of inhalational effects and the local effect of nicotine on our skin.

So you do see a measurable vasoconstriction in the skin that becomes a problem, which is why patients who smoke age faster. Patients who had surgery who smoke have a higher risk for poor wound outcomes, for poor healing because of that vasoconstriction. Usually people who use or consume nicotine aren't doing it once a week.

Most people are using it daily or multiple times a day. So that chronic vasoconstriction adds up and has a net negative effect on the skin. So if you want to keep your skin healthy, if you want to look younger, I would refrain from nicotine use. - What about vaping nicotine or oral use of nicotine?

So nicotine gum, mints, pouches. And let's touch on vaping first because that's becoming more common. - So with vaping, we see the same problems in the skin. We don't know if it's an inhalational issue or if it's actually the same concentration of nicotine that's reaching local skin causing the effect, but we see the same vasoconstriction when you match cigarette smoke with vaping if you have the same nicotine content.

Now for patches and gum, it's less of a problem. And why that is, is the concentration of nicotine that reaches the skin is much lower. Usually when you chew it, it has to go through your digestive tract, then enter your bloodstream, then reach the surface of the skin. When you have a transdermal patch, it still goes through the bloodstream, then ends up in the skin.

So because of how much it has to be processed, the concentration that reaches the skin is much lower. When we operate, when we do surgery, with any surgery of any kind, we try to transition people who smoke or vape to at least gums or patches to mitigate their withdrawal effect, but, you know, so they don't have the feelings, but, you know, it doesn't have the same constrictive effects on their skin.

- What about alcohol? You know, I did an episode of this podcast on alcohol, which somewhat to my surprise, you know, was very widely shared, only to my surprise, because I've never been a big consumer of alcohol, but apparently many out there are. And the data came back, at least to my understanding, that zero alcohol is healthier than any, and that up to two drinks per week is probably okay, as long as you're an adult of drinking age and not an alcoholic.

You don't have issues with alcohol use disorder, as it's now called, probably okay. But beyond that, you start running into some health issues that can be offset by better behaviors of other types. But what about the direct effects of alcohol on skin in the short term? Does it increase blood flow and therefore improve skin?

Are there long-term indirect effects? I could imagine that alcohol disrupts the gut microbiome, which then disrupts skin, et cetera. So maybe we could break this down into direct acute effects, meaning immediate effects that are really direct from consuming alcohol that day, that week, let's say, versus chronic effects through other systems like disruption of sleep and microbiome.

- Yeah, great question. Alcohol and skin connections, complicated, convoluted, but generally thought to be a net negative, both short-term and long-term. So first, alcohol tends to be a mild diuretic. So it makes our body dispose of water a little bit more frequently. What happens short-term is that, one, you get almost a mild diuretic effect from alcohol consumption, which is why you tend to be thirsty in the middle of the night and wake up in the morning, tend to be parched.

As a result, you see that diuretic effect on our skin. You see a little bit of hollowing in areas that you'd have normal volume and suppleness, which is why people tend to see bags under their eyes or they look like they had a hangover is from that mild diuretic effect.

Also, as a compensatory mechanism, the skin produces a bit more sebum to compensate for that drying out effect. So in the acute phase, your skin dries out, you look a little bit worse because of that diuretic effect. In patients who cannot, or people who cannot tolerate alcohol, and there are genetics in Asian populations and Southeast Asians that have a difficulty in breaking down acetaldehyde, that is a toxin that shows up in the skin and makes the skin vasodilate as a result.

So that common college term that we used to hear, you know, the flush or the glow, or incorrectly called the Asian glow, is as a result of the inability to break down alcohol. And that usually you see immediately. People get a very bright red flush in their skin because of the acetaldehyde buildup in the skin.

Long-term, one, the diuretic effect becomes a problem. So over time, your skin's producing constantly more sebum to keep the skin supple. Your skin is drying out. And as a result, you run into things like breakouts and congested skin, you know, blackheads, whiteheads, things like that. And long-term alcohol use is also associated with lifestyle choices that may make your skin health worse.

Generally speaking, when people are out binge drinking, they tend not to come home and do things that'll maintain their skin. Now, that's not a fixed rule, but most of the time when you're out, you know, having a few beers or cocktails at the bar, you tend to come home and not do your diligent skincare routine, or you may not be up, you know, with your hydration status or your dietary habits.

So that's something we can't quantify easily, but contributes significantly to faster aging, poor skin health. Then the gut microbiome question. This is a great question because the data is widely variable for alcohol consumption and the effects or changes permanent or transient in the gut microbiome. There are some alcohol products like kombucha that has a higher alcohol concentration that's healthy for your gut.

Then there's hard alcohols with a higher concentration that act as anesthetics and act as gut paralytics. So one of the things we see in people who consume a lot of high percentage alcohols is actually gut immobility and gut paralysis, partly because of the anesthetic effect, partly because of the analgesic effect of alcohol, and also because it affects gut motility as a toxin.

So generally speaking, the gut health, depending on your consumption patterns, use and concentration can be very deleterious. Some people are very sensitive and they have changes that reflect in the skin as a result of drinking a lot. And then there are some people who tolerate it more or maybe consuming things that are healthier for the gut microbiome, like things like fermented alcohols, like kombucha and things like that.

So generally speaking, the higher the concentration, the greater the problems, the higher the percentage of alcohol, the greater the problems. That includes the diuretic effects, that includes effects on the gut microbiome, that includes lifestyle habits. If you're drinking a lot of higher percentage alcohols, you tend to feel the effects, not just in the skin cognitively, behavior-wise, that can affect you.

Whereas sometimes lower concentration alcohols, depending on the setting and lifestyle, may be net neutral, may be positive. I'm clear on that part. - But I'm not hearing any positive effects of alcohol on skin health or any of this. - Generally not, generally not. Same as what we've seen with other organ systems, the brain, the liver, the skin reflects the same thing.

If anything, it may be a net neutral. Most of the time, it's a net negative. - And what I'm pulling from all of the discussion we've had up until now is that improved blood flow and strong hydration status are both important. Do you recommend patients drink a certain amount of fluid each day or maintain adequate hydration as a means to build or maintain skin health and appearance?

- Great question. So that's another common misconception that I see in that thinking drinking a lot of water will, or drinking a lot of fluids will directly affect the hydration status of their skin. And while there's a certain degree of truth to that, if you're dehydrated and that you need replenishment of fluid systemically, every study that's looked at transepidermal water loss has not shown a great connection with regular fluid intake and water intake and skin hydration status.

We find that that tends to be genetically defined and genetically encoded. Some people have drier skin. They need more methods to moisturize their skin. Some people have oilier skin and their sebum provides that moisturization. Now, if you're doing things, if you're active, if you're an athlete, if you're doing things in which you are dehydrated, then totally different story.

But if you're living a more or less balanced life or a sedentary life and you're doing all the regular things, drinking a lot of water or fluids has not been shown to improve skin health. So that's why generally speaking, most dermatologists will recommend some sort of moisturizer to replenish that.

But you gotta know your skin. For example, my skin, I tend to be oilier. I don't usually need a moisturizer as much. Whereas somebody who is drier will need some sort of barrier protection to allow, to minimize that trans-epidermal water loss. - What are some of the parameters for selecting a moisturizer?

- Yeah, there's a lot of stuff. - People are immediately gonna go into say, well, what constitutes a good moisturizer? What should it have in it? What are some things to avoid? - Yeah, it's a crazy market. There's a lot of things out there. You can Google skin snail moisturizer and you'll find people putting snail mucin on their skin as a moisturizer.

- You were telling me before this recording started, there are people who, and forgive me for those that cringe when I say this, that put placental extract. - Human placenta as a means of rejuvenating their skin health. I don't advocate it or don't say anything against it, but I probably wouldn't recommend it.

There's better, safer, more cost-effective ways of doing this. Simple things you wanna look for. One, is it non-comedogenic? That's a word you wanna look for for any moisturizer that's been tested not to clog your pores. That's a basic thing to look for where you won't cause another problem in trying to fix one problem.

Number two, how oily or dry are you? Generally speaking, there are three flavors of moisturizers. There's ointments, there's creams, and there's lotions. Ointments are greasy. They're like petrolatum jelly or Vaseline-based. Those are the best for moisturizing your skin, but they're greasy. Then there's creams, which are water emulsions with oil suspended in it.

And then there's lotions, which are generally powders that are resuspended with water. We as dermatologists tend to like the greasier the better. It provides the best barrier protection, but you have to know your skin. If you're somebody that is eczema-prone, you will need something that is an ointment that does better to protect the skin from drying out.

If you're somebody that is acne-prone, you won't tolerate greasy things. You'll break out more. So you wanna look for a lighter moisturizer that's non-comedogenic. So in a long story short, it's very person-to-person specific. You gotta know your skin, but the fundamental things you wanna look for is has this been tested to not clog pores?

And is it in a pump bottle or is it in a jar? Jars tend to be more occlusive. They tend to provide more moisturization, but they can lead to problems like acne and breakouts. Whereas things in a pump bottle, because they're powders in suspension and they have to put alcohol in the product to allow it to come out of the pump mechanism, they tend to be lighter and not provide as much moisturization.

- I see. So when I think about something in a jar, you have something like Aquaphor or something, which is pretty thick, thick stuff. So that would be fine for someone with eczema, not okay for somebody with acne. - Yeah, exactly, exactly. The greasier, the more occlusion it provides, but in doing so, it clogs everything.

Now, if you're one that has some sort of skin issue in which you need that, it's the best thing. If you're one that is breaking out all the time, you want something lighter. - I'd like to take a quick break and acknowledge our sponsor, AG1. By now, many of you have heard me say that if I could take just one supplement, that supplement would be AG1.

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Again, that's drinkag1.com/huberman to claim that special offer. Why do people wake up with bags under their eyes if they just slept for six or eight hours? - Yeah, well, maybe you need a little bit more sleep or maybe you had a wild night, I can't tell, but generally, the bags are caused by two things.

One, fluid retention. So there's some lymphatic change that occurs under the eyes that's most noticeable because the skin under our eyes and on the surface of our eyelids is the thinnest. So fluid changes are seen the quickest there. And as we're in a supine or prone position, fluid moves from our extremities back to our central venous system, and it's easier to collect in the face.

So we see it around the face. The other thing that we do notice with bags is just age-related fat herniation that shows up more as we wake up because of positional changes. So if you've had a heavy meal the night before, something that has a high salt content, you're gonna retain a little bit more water because of that solute shift.

You may notice your eyes are puffier in the morning. If you have allergies, seasonal allergies, asthma, eczema, they run in a family, that tends to make your skin retain a little bit more water as a result of that allergy response. So people will notice springtime or fall time, their eyes are swollen or their eyes are puffy, especially when their allergies are flaring.

It's a product of water retention from all the histamine release and changes that occur in the skin. - Skin cleansing is a topic that gets a lot of coverage. And I sometimes get chuckles or even attacks for saying I've always just used unscented dove soap, the bar, not the liquid soap, or like a Cetaphil soap.

And this is because when I was younger, like much younger, I had very sensitive skin when I was like a kid, seven, eight, nine years old. I think I just started using unscented dove soap at some point and things like it, gentle soaps without fragrances. What are your thoughts on those?

And I ask not for my own purposes, I'm gonna stick with it because it works for me, unless you tell me I shouldn't, but I see this enormous market for skin cleansers that includes a range of costs from relatively low to near astronomical. And if you tell me that this unscented dove soap or Cetaphil soap is the way to go, and by the way, I'm not sponsored by either of those, I don't even know who they're manufactured by, so there's no commercial angle here, but I'll be relieved because they tend to fall on the lower end of the cost bracket relative to some of these astronomically priced cleansers.

- Skincare is a incredible multi-billion dollar market. That being said, there is not a shred of evidence that anything more expensive works better than anything cost-effective, so that's first and foremost. Number two, dove white bar soap is amazing. It's what we recommend for newborns and kids with sensitive skin.

Generally, when we say sensitive skin, especially in kids, toddlers, and adolescents, there's a component of some sort of eczema or atopic dermatitis that is not bad enough to have a diagnosis, but enough to say, I had sensitive skin. So dove white bar soap is what I use for my kids, and I'm not sponsored by anybody either, but I think it's an amazing product because it's safe, it's effective, it has the least amount of ingredients, no fragrances, these are all things that can irritate or cause an allergic response to skin that is sensitive, meaning your skin mounts an immune response to some sort of environmental allergen or trigger.

That's what we generally mean when we talk about sensitive skin. I personally use Cetaphil, that's my face wash. I have oily skin, and I use the one that takes off more of the oil. So what you're looking for is defined by what bothers you or what your skin predicament is.

What I do see as a problem nowadays is particularly in the United States, we're a hyper-hygienic society. So what people tend to do is over-cleanse, and they over-cleanse for several reasons. One, because they are told that cleansing will fix their skin issue, or number two, they're told that some sort of organism is on their skin or some sort of bacteria that needs to be cleansed off to keep their skin healthy.

Neither are true. The first thing you want in terms of a cleanser is something that's mild, fragrance-free, and has been tested to be hypoallergenic or non-comedogenic. That's first. Cetaphil, Dove, CeraVe, great, great stuff. No association with any of them. - The unscented, non-fragranced versions of them. - Exactly, that's first.

Fragrances tend to be a problem for sensitive skin in patients who have atopic dermatitis or eczema. They tend to trigger allergic responses or exacerbations of their eczema flare, so we try to avoid fragrances by all means. Then, things that are gels or liquids tend to have preservatives in them to increase shelf stability, whereas bars tend not to.

So if you are gonna pick something that is a gel, a liquid, look for one that's been tested by a dermatology group or verified by the American Academy of Dermatology as one that is not allergenic or has multiple preservatives because that's another well-known but unidentified source of problems. Well-known to the dermatology world, not known to the average person that the preservatives in our cleansers are a problem.

Over-cleansing becomes really problematic in eradicating the skin microbiome. So what we see a lot of times are cleansers that are either bactericidal, bacteristatics, things like benzoyl peroxide, things like salicylic acid, things like certain astringent toners that are alcohol-based, and what they do is not only do they strip the normal oils from our skin that keep our skin supple and healthy, but they eradicate the normal host skin microbiome.

Those are all the microorganisms that live on our skin, and we have trillions of them actively surveying our skin, living in normal symbiotic homeostasis, meaning they're our friends, they're living there for a reason, they don't cause any problems. But when you cleanse them off, you open up an area for pathogens to take effect, and that's when we see a lot of problems, more so in industrialized countries.

The United States is a notorious place for washing, especially after COVID, wash, wash, wash, wash more, use a toner, wash some more, and that becomes really problematic because it sets up for organisms to take seed when they shouldn't be there. So overall, cleansing is great, and the amount that you need to cleanse is based on how oily or sebaceous your skin is.

The older you get, you may not need to cleanse as much. Older patients don't need to cleanse their skin at all every day because they don't produce as much sebum or oil as younger patients. But everything should be defined by your skin's characteristics. So if you are one in which you notice, by the end of the day, I'm oily, I'm breaking out, cleansing may be something that's beneficial for you to take off that excess sebum.

If you're one that has dry skin, if you're one that had sensitive skin as a child, then over-cleansing is gonna be a problem. You're gonna wanna minimize that and keep that moisturization or that barrier protection going. - So does that mean that people should bathe probably once or twice a day, but the people that are bathing three times a day, it's probably excessive?

I mean, are we saying that you can't get into water? I mean, when you say cleansing, you're talking about face cleansing. I realize this is going to be highly individual, but some people are just out of habit, shower and use cleanser twice a day or once a day. I think for me, it's in the morning or in the evening, sometimes both.

If I do a workout, I try and shower as close as possible after the workout, as soon as possible after the workout, rather, because otherwise I will break out. So it sounds like one has to kind of learn what their cadence is, and that's going to vary by age.

There's a lot of factors to this. I think Ashton Kutcher and Mila Kunis famously said they shower, I think, once a week or something like that, and it stirred up a lot of conversation when that came out. Truth be told, you don't have to cleanse every day if your skin is otherwise fine and healthy and you're not bothered by anything.

You live a lifestyle in which you're not sweating excessively or producing a lot of sebum. I, myself, same thing. I work out, so I shower after working out, and I usually shower before I get into bed because after a long day of work, I tend to have things on my skin that shouldn't be there.

That's only fitting for me because if I don't, I tend to have problems. I tend to break out. I tend to have things that shouldn't happen because of my hygiene habits. That said, there is no indication or no medical necessity to have to cleanse your skin even once a day.

Oftentimes, older patients cleanse or shower once a week, and they're totally fine, but it'll have to be defined by your skin and what problems or ailments are specific to you. Generally, if you work out, if you let sweat dry on your skin, it causes several problems. Number one is irritation itself from the salts that crystallize from the sweat drying off.

Number two, the sweat itself is a source of food for certain yeasts that are normal symbiotic yeasts that live on our skin, so it contributes to things like dandruff, what we call tinea versicolor, which is a type of yeast that grows on our skin. So generally, if you work out, try to wash those things off.

Also, if you are one of acne-prone skin, if you're an adolescent, if you're a teenager, if you're an adult dealing with acne, the sebum that your body's producing is food for the bacteria that cause this. So you tend to want to clean some of that excess sebum off. Those are simple indications to cleanse both your face and your body.

But if you're not having any problems, you actually don't need to do any of that. In Europe, they shower and cleanse at a fraction of the frequency that we do in the United States. And when you look at incidences of the most common skin conditions, they're the same. - Including things like acne, psoriasis.

You know, most people think about shampooing for sake of hair, but there's the scalp component. And since you're an expert in skin, we should probably spend a bit of time on this. For people that tend to have a dry or flaky scalp, what should they do about that? My understanding is that some of the more typical commercial anti-dandruff shampoos can contain things that might cause issues for hair itself.

So they might help with the flaking and drying of the scalp, but damage other aspects of, you know, either appearance or health of hair. What are some really good options for people that have dry scalp? What are some great options for people that have oily scalp? And let's leave aside the frequency of use and just perhaps just put it on the shelf as much as you need it, but not more.

So that could be once a week, it could be daily. Could be twice a day if in extreme cases, it sounds like. - So when we think about the scalp, when we think about dry or flaky scalp, we think about two main conditions, either seborrheic dermatitis, which is medical grade dandruff, or, or the medical name for dandruff, or psoriasis.

They're two different entities, but they generally contribute to the same problem, which is redness, flaking, and dryness of the scalp. Now, it's important to note that the hair on your head is dead. It's not alive. The only area that's alive is two and a half millimeters in the skin.

So the hair that we see on our scalp is not a living entity. So there's a common misconception that you can affect the health or quality of your hair by putting things on the hair. And I'll go into that in just a minute. But the hair itself that you see is not living.

The only area that's living are the stem cells in the papilla of the hair, and in the bulge region of the hair, which reside in the skin. So nothing that you put on your scalp will make you lose your hair, will make you grow new hair for the most part.

Why that's important. When we treat dry or flaky scalp, we treat it with several things. The most common cause is an overgrowth of yeast from the sweat and oil that is produced from our scalp. And that's seborrheic dermatitis. That's the medical name for dandruff. And so we treat it by, one, lowering the amount of that yeast that's living, and that's usually with shampoos that are prescription, or over-the-counter.

Things like zinc or ketoconazole shampoos are very common things. And then the other thing that we do is to dampen the immune response to this overgrowth of yeast. So the reason our skin flakes and gets red and proliferates is our immune system's responding to something. It's either responding to the yeast or it's responding to itself, which is what psoriasis is.

It's an immune-mediated overproliferation of skin cells because the immune system is overactive in the skin. And the way we treat that is just topicals or certain medications that suppress the skin's immune system or immune activity. None of that affect the actual hair itself. What does happen is shampoos tend to have things that strip oils as a mechanism of cleaning.

So when you take a cross-section of the hair, there are seven layers. And the layer that provides that color, sheen, and structure is called the cuticle. As we age, we lose the cuticle. And that's a common problem, what we see in male and female pattern hair loss or androgenetic alopecia, is we lose that cuticle, which makes us lose the shine and the structure and the strength of our hair.

Our body tries to replenish that with the oils. So when people wash their hair, sometimes they feel like the hair becomes more limp or dull or lifeless. It's because we've taken that artificial oil coating that replaced the cuticle and washed it off. So good news is you're not gonna do any harm putting any of the topicals on your scalp.

Bad news is you probably won't bring a lot of it back to life either. But when we treat flakiness, redness, things like that, we're treating two entities, usually with topicals, and because we're either trying to treat overproliferation of something, or trying to calm down the skin's immune system. - Got it.

So it sounds like the best options for cleansing skin, for shampooing, really stem from knowing whether or not your skin tends to air oily or dry, figuring out how often to cleanse. And then as you pointed out before, even though there's an enormous range of costs for these things, none of the solutions that you're describing sound like they fall on the high end of cost, or even in the middle end of cost, which is a bit surprising to me.

This might be one of the few areas where, like if I had a magic wand, I would make for all organic, non-processed and minimally processed foods to be very inexpensive. But it turns out those things tend to be more expensive. You can go to farmer's markets and cut back on the cost, et cetera.

But there seems to be an unfortunate trade-off between availability and cost and benefit, or at least risk. But it doesn't sound like that's the case with skincare or scalp care, that one can exercise really excellent skin and scalp care without having to go into a range of spending an outrageous amount of money.

- No, I think, one, you're absolutely right. The more expensive does not mean better. In fact, they sometimes become more problematic because there's more ingredients in the more expensive products, including elegant fragrances and stuff like that, which can be problematic. That's number one. The second thing to know is that, generally speaking, there's some connection between skin health, skincare, and this realm of beauty, which people overlap a lot in.

And when we trend into this realm of beauty, glamor, et cetera, price and objectivity are taken out. And that's why you see a lot of skincare products that are so expensive, because they draw towards another level of desire that's not just medical, it's aesthetic. And that's where you'll find creams that are $200, $300 for a little amount of cream that does the same thing that your jar of petrolatum or Vaseline or Aquaphor does.

That part is really hard to mitigate. But in general, almost everything that we as dermatologists and skin cancer surgeons and experts in the field recommend are really cheap, cost-effective, and they have the least amount of ingredients in them. And that's what I would recommend. That's what I recommend for my family and for my patients.

You don't have to spend a lot to have excellent skincare, and you don't need to have it be a multi-step routine. Oftentimes people overdo it. The more steps that there are, there's more chances that something your skin will respond to negatively. The more chances you are to have a bad outcome to an ingredient of a product you're putting on your skin.

So keep it simple, keep it cheap, and you'll do great. - It's going to be very reassuring to many people. It's also going to be somewhat destabilizing to people who are really attached to the idea that the more expensive products are really doing something that much more beneficial for them.

- Not much at all, not anything. Another important thing to consider when looking at skincare, skin health, and then trending into that area of aesthetics and beauty is that most active ingredients, if they're really active, tend to be controlled by the FDA. So most things that are sold over the counter have actives that are not at a concentration high enough to be considered therapeutic, because that's when you get into the definition of a drug.

So looking at things like anti-dandruff shampoos, anti-aging creams, acne medications, they work a little bit. If they work perfectly, then most medical dermatologists would be ahead of a lot of patients, and we see a lot of skin disease that still continues because the active ingredients aren't at a concentration high enough to provide therapeutic benefit.

So save your money if you really need something to change some part of your skin, see a good dermatologist, see an expert, and see what they can come up with. - So this seems like an appropriate time to ask about sun exposure. And then we'll also talk about sunscreen, sunblocks, skin cancer.

- Sure. - But what is the relationship between sun exposure and skin health specifically, meaning how much sun exposure is healthy for our skin? I'm a big believer in getting sun exposure to the eyes early in the day, blinking as needed to protect the eyes, of course, but in order to set one's circadian rhythm for elevated daytime mood, focus and alertness, and improved nighttime sleep.

There's just so much data to support setting one's circadian rhythm properly for sake of health. And there's so much data to support the fact that sunlight viewing in particular is the best way to do that. And sunlight viewing in the early part of the day in particular is the best way to do that.

But beyond that, how much sun exposure to the skin is good for us? Is it zero? Is it five minutes? Does it depend? - Great, like great controversial question. And it depends on which school of thought or camp you belong in. As a skin cancer surgeon and somebody who's developed a reputation for seeing some of the worst, most complicated and life-threatening skin cancers in Los Angeles, obviously I see some of the consequences of long-term sun exposure and chronic photo aging.

That being said, I absolutely think that getting sun is healthy for us. Now, why? The studies that talk about vitamin D, and we'll touch on vitamin D as its own entity, and then overall health as another entity, but most of the studies that look at vitamin D synthesis from UV exposure on the skin suggest that you only need about 15 minutes and that you don't need a broad surface area of exposure.

You can get enough vitamin D formation with just about 15 to 20 minutes of sun on your forearms. So there's a whole school of thought by a lot of experts who think there's no amount of UV exposure that's healthy for the skin. And I tend to be on the other camp for several reasons.

One, there is a component of feel-goodness if that's a word from being in the sun that affects overall skin and physical biology. When you're out in a sunny day, you tend to be less stressed. You tend to be a little happier. Now, it's a generalization, but most of the time when you get outdoors, you get outside and it's a nice sunny day, you feel better.

And although you can't quantify that feeling better, there are some parameters that can be measured. Decreases in cortisol response, improvements in skin appearance and texture. The other important thing about being out in the sun is finding out your own tolerance, right? So I have a little bit more olive skin and I can tolerate the sun a little bit longer than somebody who is fairer and lighter eyes.

In my opinion, I don't think in most of the evidence, there isn't a finite amount of time because that time is dictated by your skin's ability to tolerate the UV. But I absolutely do not think that sun avoidance is a healthy thing. And this is coming from somebody who operates on head and neck skin cancers literally every day.

I think there is a component of sun exposure that's not just for vitamin D synthesis, but something that improves your overall wellness that is visible and maybe not laboratory measurable, but you definitely are healthier when you're feeling better and you're happier. I lived on the East Coast in places that had lower days of sun and I had seasonal affective disorder.

It bothered me. My mood was lower. I felt not as healthy. I'd come home, my family would say, "Hey, you look sick." And it just, I wasn't sick. I hadn't had any sun and I was lighter than I was. And my family interpreted that as not being healthy. My wife, on the other hand, didn't.

She didn't mind the grayness. So there's a timeline for biologic processes like vitamin D formation that's helpful. People can argue that you can get it through supplementation and food and that's correct, but there is a component of sun exposure that makes you feel better overall and provide some sort of wellness that you may not be able to quantify, but you see an appearance and in discussion and longevity.

So absolutely, I think you should be out in the sun. I don't think you should burn and I don't think you should be out long enough where your skin starts to turn red. That's the first sign that you're reaching kind of critical mass in terms of UV exposure, but I absolutely think the sun is a good thing for us.

- So even midday sun, maybe if there's some cloud cover or if we have some sunscreen on or a physical barrier like sun and long, excuse me, like hat and long sleeves, then getting some sun exposure in your mind is good for our overall wellbeing, mood, et cetera. - Yeah, I think, I mean, midday sun has a higher UV index, so you're more likely to burn and have a problem with prolonged exposure, but yeah, absolutely.

I think there's been numerous studies that have looked at people who go out for a walk in busy urban cities in work environments. If they go out for a walk in the sun, they feel better. Their stress responses are lower, their questionnaires in responding to life stressors and day-to-day stressors are decreased.

There's a lot of studies that look at being outside as a measure of wellbeing, mental health wellbeing is improved with outdoor sun exposure, so there's a lot of that. Now, can I quantify it in the skin? Hard to say. One thing we do know is that obviously too much sun exposure, like anything, too much of a good thing can be a bad thing, but I really do think that being out in the sun for the amount that your skin can tolerate is a good thing.

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You know, in the old days, as I understand sunscreen was the word used to describe stuff that you put on your skin that absorbs UV and then sunblock is the stuff that you put on your skin to reflect UV. Typically nowadays, people say sunscreen more than they say sunblock, or they use them interchangeably without any knowledge of the underlying mechanism.

So first of all, let's clarify sunscreen versus sunblock. - Yeah, so a lot of the nomenclature data, understanding chemicals, things that were considered okay to be used came from an original FDA 1999 manuscript. And that data hadn't changed for almost 20 something years. And more recently, in 2021, the FDA released a proposed final order for the term sunscreens as a whole.

Now, when we talk about sunscreens, sunscreens are considered an over-the-counter non-prescription drug. So they're regulated tightly by the FDA. They're in the same category as any over-the-counter drug. So before this decision ruling, there was a lot of nomenclature, wording, confusion. Sunblock seemed better than sunscreen, sun tan, sun tan oil.

All of that's been changed recently or has been proposed to get rid of to unify the field and make it very clear what the goal is. So no longer do we use the term sunblock, although in the past, that had been used for things like zinc or zinc and titanium-based creams, like the old 1980s or 1990s white lifeguard noses, if you remember.

That used to be thought of sunblock, whereas less protective chemicals were used as sunscreen. Now that's changing. And the FDA 2021 proposed order says we need to unify everything and call it a sunscreen. Now, sunscreens being regulated drugs take a lot of scrutiny for many reasons. They take scrutiny from the FDA in terms of proving efficacy and safety.

They take a lot of scrutiny in society for being dangerous or not dangerous, effective or not effective, causing downstream effects or not causing downstream effects. So that's been a big point of contention in terms of the population, the American Academy's stance, dermatologist's stance, and then the skin cancer patients' beliefs, the beauty experts' beliefs, and average person's opinions.

Sunscreens generally fall into creams, lotions, topical products that protect the skin against sunburn. We used to be able to suggest that they reduce the risk of skin cancer, prevent it premature aging, but that can be a little convoluted. And the FDA is rewording that into not being able to say that anymore in their proposed order.

But what sunscreen's intention is is to protect the skin against excess UV exposure. And they come in two flavors. They come in mineral-based sunscreens, which tend to be in the category of zinc and titanium minerals. And they tend to be chemical sunscreens, which are a bunch of different chemicals.

- Mineral-based sunscreens are sometimes called inorganic, correct? - Yeah, inorganic or physical sunscreens, whereas the chemicals are considered organic or chemical sunscreens. Totally right. - Is the mechanism for these two the same? Because I was under the impression that the mineral-based inorganic sunscreens reflected back UV rays, whereas the chemical-based sunscreens absorbed UV rays.

But there's a bit of a online debate about this, claiming that they all absorb UV rays. - Yeah, so historically it had been thought that mineral or physical sunscreens, zinc, zinc, and titanium sunscreens, worked by basically acting as a metal reflecting shield. And for the most part, that thinking is not incorrect.

There was a new study that showed that they work by actually absorbing them, but not having any sort of chemical change. So the way chemical organic sunscreens work is they absorb the ultraviolet radiation, they undergo a chemical reaction to reduce its energy and dissipate that energy as heat. So chemical sunscreens work by actually absorbing it and undergoing a change, whereas mineral or physical sunscreens don't do that.

I still think of them simply as minerals basically shield the skin like armor, whereas chemicals act as a sink and undergo a change to reduce that energy. So that's kind of the simplistic way that topical sunscreens work. - So what is your recommendation about protecting oneself from the sun?

And maybe for the moment, let's just set aside sunscreens and acknowledge that a physical barrier like hat, long sleeves, long pants, provides a pretty good barrier to the sun, correct? - Yeah, in fact, physical barriers like shade, clothing, hats have been shown to be more effective than topical sunscreens for several reasons.

But there are many ways to protect your skin and you have to ask why you're protecting your skin. So is it because you're worried about premature aging, photo damage and things like of that nature? Are you worried about your risk for skin cancer? Do you have a sun sensitive skin condition like lupus or PMLE that is sensitive to UV exposure?

So the first question is, why are you worried? Or why are you taking protection? And then you customize your approach to that. Now, sunscreen, topical sunscreens are not the only form. By and large, there are many other forms, both physical blockers and certain things in the supplement world that can protect your skin.

For example, I myself take a product called sun powder that provides an internal sun shield and allows me to be in the sun longer without the need to reapply or if I can't reapply. But by and large, the best way to protect your skin is some sort of shield, whether it's clothing, hat, or some sort of cream that you put on.

Now, for patients who are worried, or for people who are worried about premature aging, they don't have a strong family history of skin cancer. They've never had one before themselves. Then the approach to that is a little bit different than people who are worried about skin cancer development, strong family history of skin cancer.

They're worried about losing a part of their ear or a part of their nose to skin cancer development. And that's very different from medical conditions that are very sun sensitive. By and large, the patients who have medical conditions that are sun sensitive, the large one being lupus, for example, need the most sun protection because they are so inherently sensitive to UV exposure.

Something that's very interesting. We know without a doubt that every common skin cancer, there's many, many skin cancer types, but the three most common are basal cell carcinoma, squamous cell carcinoma, and melanoma. Those are the three most common ones we see. They have all been shown to have UV mutation signatures when we sequence the tumors.

However, in every single clinical trial and every single randomized trial that looked at topical sunscreens as a means of reducing risk, there has not been a single study that showed any sort of risk reduction in the development of the most common skin cancer, which is basal cell carcinoma. One in four Americans will develop this.

Also, there hasn't been a single study to date that showed that diligent sunscreen use, topical sunscreens, will reduce disease-specific death or dying from skin cancer. So if you think every skin cancer is sun driven, there are UV mutation profiles in these tumors, then by using sunscreen should reduce that, right?

And it's not that clear. We don't understand fully the drivers of this. So why I bring this up and why we talk about sunscreens and barriers to blockade? First, topical sunscreens are not the only form. In fact, clothing and shields, shade and hat are, in my opinion, better, and a lot of studies suggest that they're better.

There are oral supplements that can also protect your skin from burning and reduce your skin cancer risk. And number three, not everything is sun driven. We do know that diligent sunscreen use decreases the incidence or the amount of melanoma formation and squamous cell formation, but we still don't know whether that reduction has changed the number of patients dying from that.

We also know that it has no bearing in the development of the most common skin cancer, which is basal cell. So we go back to the drawing board and scratch our heads saying, "Hey, what is the trigger?" The genetics loads the gun, for example, and maybe even pulls the hammer, but what in the environment is the trigger?

Is it strictly UV? Is it some other culprit? So sunscreens are a really hotly debated topic. So many things to talk about in terms of sunscreen. - So if I understand correctly, you're saying that the use of sunscreen can protect against premature aging. Let's say sunblock, because I think we're going to arrive at mineral-based sunscreens probably being the better option, but we can make sure that we double-click on that, so to speak.

But that sun exposure itself perhaps is not linked to the most deadly of skin cancers. That tells me two things. It doesn't tell me that I can just spend as much time as I want in the sun, but it does tell me that I should probably look into the things that cause the most deadly skin cancers.

- Yeah. - Okay. But I'm also hearing that regular application of sunblock and/or physical barrier will protect my skin against some forms of premature aging caused by sun exposure, but will not necessarily protect me against the most common forms of skin cancer. That is peculiar in the sense that, or even baffling to the non-dermatologist, me, because we already know that sun exposure causes UV mutations.

Mutations in the DNA of cells is one of the kind of core components of cancer. So how do we square all of this? - Great question. And the more we dive into this and the more experts we look at and the more data we collect, the more we're scratching our head as to, we don't know, and why this occurs.

Now, I'm not saying don't use sunscreen. Let's just let that be known. I think sunscreens are excellent forms to protect against premature photo-aging and signs of sun damage. I think sunscreens help reduce the incidence of common garden variety skin cancers, but they are not the only form of protection and they seem to not be as important or have as much effect in reducing the incidence of our most common skin cancer, which is basal cell carcinoma.

Moreover, I would say, and the data unfortunately shows that the majority of skin cancers that we see that end up hurting people or killing patients don't arise in chronic sun-exposed areas to begin with. I have a 27-year-old patient right now dying of a metastatic melanoma that arose in completely sun-protected skin.

I have a 56-year-old mechanic right now who's dying of a squamous cell carcinoma that arose from the back of his ear. And most experts who have this type of experience dealing with these patients have the same observation. So the question is, what's pulling the trigger? For the most part, UV plays a big role.

The mechanism in which cancer forms, if we believe the basic high school biology is, you know, hyperplasia, metaplasia, dysplasia, carcinoma. So there's a trajectory of changes that are occurring as a result of cumulative mutations in the skin. If we believe that trajectory, then every skin cancer should see that change, and we just don't see that.

Also, we know that skin cancers that arise in sun-damaged skin behave differently than the ones that are very lethal. So why I bring this up, I think sunscreen is very helpful, but we have this unfortunate trend in medicine, particularly in dermatology, to guilt people into thinking that they cause this to themselves.

And I don't think that's right nor okay, and I don't like that. Because they make it seem that, oh, the sun you got in 1987, that one sunburn in Hawaii did it to you. And that's absolutely not the case. There are many things at play, fundamentally your genetics and immune system, that play a huge role in skin cancer development that sunscreen cannot address and will not address.

Now, the wild card is, okay, what are my genetics? And that's the part we don't know, which is why dermatologists say, okay, let's at least control the thing that we can, which is UV exposure. But I bring this up because, don't feel bad about getting some sun, and don't feel guilted into something that, if something bad occurs, it's not your fault.

Some of it is out of your control. And that's really important, 'cause I see a lot of very bad skin cancers in my practice. And I hate this feeling of patients feeling like they did it to themselves. - I think most people would prefer not to have the premature aging caused by sun exposure.

So what should those people do? I've taken on a practice of putting a mineral-based, inorganic sunscreen on my face, my arms if they're going to be exposed, back of my neck, tops of my ears. If I'm going to be out in midday or late day sun that feels intense, and I'll do that every single time I go out now.

On overcast days, not so much. For viewing morning sunlight, I don't do that. In fact, when the sun is low in the sky, I don't tend to wear sunblock. That's me, that's been my choice. There were a few years there where I didn't put on sunscreen, or if I did, it was like on a camping trip or skiing or something where the sun felt very intense.

And in that case, I would just reach for whatever sunscreen or sunblock was available because I wasn't aware that some of the ingredients in certain chemical-based sunscreens may be problematic. So I think I fall into the typical category of a lot of people. But of course, there's the category of people that are like, nope, sunscreen sunblock is terrible all the time, or they're just too lazy or uninterested in applying it.

But then there's this whole category of people that are putting it on every single time they go outside in hopes that that's going to keep their skin appearing much younger, and just generally are kind of afraid of the sun. - A lot of good points. So there's that famous New England Journal of Medicine picture of the truck driver that got chronic sun exposure on the left side of his face, and you see all this wrinkling and modeling of the skin on the left side and nothing on the right side.

So by absolute measure, sun protection or UV protection will reduce premature aging. Now, interestingly, that guy did not develop anything in that area. So again, it goes back to, well, what's pulling the trigger? - No skin cancers. - So the question is, what's pulling the trigger? Is it truly UV, or is there something else we're missing?

- If you tell me that he got skin cancer on the opposite side, I'm really gonna gasp, but no. - I don't know if he's had any on the opposite side, but in that photo, it's purely premature aging. So things that you wanna do. Obviously, don't let your skin turn red.

Take some form of barrier protection, whether it's a sunscreen, a supplement like polypodium, something that protects your skin from the inside out. And skin changes are cumulative. So what we can tolerate in our teens and 20s is very different than what we can tolerate in our 40s, 50s, and 60s, because there's a cumulative mutation profile burden that we see.

Interestingly, there was an eyelid study that was published recently that looked at eyelid skin that was removed during cosmetic surgery, upper eyelid lifts, that was otherwise discarded. And when they ran genetic sequencing on normal eyelid skin, they saw the same mutations that they would see in matched skin cancers, but the eyelids didn't have any skin cancer.

So we know UV triggers these mutations, and we know UV degrades collagen and elastin. It thins blood vessel walls as a mechanism of its effects on the dermis. The data is equivocal as to how those mutations trigger skin cancer formation, but in terms of premature aging, absolutely. So you wanna take some form of protection.

Now, what type of protection do you take? Depends on your genetics, how much you can tolerate, and what your family lineage looks like. Some people have the genetics of early aging. It's part of their skin biology, and you can't change that, but you can mitigate that risk with more strict UV avoidance.

Some people, they look young, longer. Some family lineages just have great genetics in their skin. They can tolerate a little bit more sun. In terms of physical sunscreens versus chemical sunscreens, that's a hotly debated topic. In my personal practice and for my family, I tend to only recommend mineral zinc or zinc and titanium sunscreens for several reasons.

In the original set of sunscreens that were approved by the FDA that came out in 1999, there wasn't enough data to look at biologic effects, efficacy, internal organ involvement, et cetera. Fast forward 20 years, and we've gathered a lot more information about these chemical organic compounds. There was an amazing 2020 study that looked at absorption of chemical sunscreens when they're applied onto the skin.

They looked at absorption with single application, and they looked at absorption over four days of application. Now, in the study, they applied a little bit more than real world experience would, but even with single application, they saw blood plasma absorption of these chemicals that were 100 to 500 times greater than the upper threshold defined by the FDA.

Now, the question exists, okay, what does that mean? Is this healthy? Is this not healthy? Is it neither? That's still up for debate, but in looking at the more recent literature and looking at the chemical structure of these compounds, a lot of these are phenolic compounds, meaning they have one or two, usually two benzene rings attached together, and they look very similar to one another.

There's been a lot of basic science, animal study, and retrospective human studies in the last two or three years that suggest that some of these chemical compounds, particularly oxybenzone, particularly octocrylene, particularly octinoxinate, that can have endocrine disruption or affect the nervous system because they mimic a lot of biologic phenolic compounds and a lot of biologic hormones.

If you actually look at the structure of oxybenzone, it looks very similar to the structure of bisphenol A, which has been now banned in a lot of the lining of plastic bottles. Why? Because of the same concept. Now, the data's not 100% one way or another, but there's enough smoldering evidence that makes me think, hmm, we should reinvestigate this.

And in fact, the FDA's proposed final order in 2021 changed these chemicals from GRACE, generally recognized as safe and effective, to not-GRACE because of these concerns. There's data that suggests that the chemicals are found in breast milk, amniotic fluid, blood plasma, urine. So there's a lot of things that we don't know, and I always say this in science.

We take two steps forward and then maybe one step diagonally or sideways 'cause we ran into unexpected things. I tend to recommend mineral sunscreens because they don't have any of that data. They haven't for the last 30, 40 years. They're considered safe. And in fact, for young kids, particularly those six months and under, the American Academy of Dermatology and the American Academy of Pediatrics generally recommends avoiding chemical sunscreens.

Why? Children's skin, particularly infants and toddlers, behaves more like mucous membranes than adult skin. Their barrier is not as tightly woven, so they absorb these things at a much higher concentration. So if you are to apply something on kids, especially young kids six months or under, we recommend minerals to begin with.

So I say, if you have a pool of compounds that has maybe even smoldering evidence on the basic science level that something's off versus a group of compounds that have really no data, which one would you pick? And they do the same thing. I naturally gravitate towards that. - So the takeaway for me is physical barrier, no issues.

Mineral-based sunscreen, safest. So that zinc oxide, titanium dioxide. - And that's mineral, not like powder, not mineral powder, but mineral topicals because mineral powders are a whole other issue we'll talk about, but. - Okay, and then chemical-based sunscreens, probably best avoided. And then you mentioned polypodium. So this is a pill, it's a supplement basically that one can take.

I only call it a supplement because it's not a prescription drug, correct? - Yeah. - That protects your skin from UV damage from the inside. - Yeah, so exactly right. Mineral-based creams and lotions, I tend to prefer and recommend in my practice and most people will if you're worried about any risk, any consequence.

Chemicals, I tend to personally avoid. Now, this may not be in line with all my dermatology colleagues, but I tend to avoid them and I do not recommend them for kids. In terms of things that you can do in addition to provide sun protection, polypodium's a fern from the Amazon rainforest that was discovered when they studied an indigenous population that would eat this fern before they would go on their fishing expeditions on the Amazon.

And they'd be gone for three days, they'd eat this fern and come back not burned. So a lot of studies were done on this fern in the last five, 10 years that showed it increases your skin's minimal erythema dose, the amount of redness your skin gets from UV exposure.

That's our general barometer for effectiveness without any topicals. It's taken or ingested orally. I personally use a form called sun powder that also has nicotinamide in it, and we can talk about nicotinamide later. But if in and of itself, it works great, in conjunction with topicals, you get the best of both worlds.

You get internal shielding and external shielding. Now it is a supplement, so it's not a controlled drug the way the FDA regulates sunscreen. So it isn't really a sunscreen, but it's a way to prevent sunburns, increase the amount of time you can be outside, and increase the efficacy of your topicals.

So if you're somebody who has very fair skin, who burns all the time, or if you're somebody who has what we call sun hives or prickly sun rash, PMLE, this is an added thing that you can use that will boost your sun protective factors. It's awesome. And if you're somebody who's active, like you're in the water or you're exercising or you're playing a sport and you can't reapply, I love polypodium for that added benefit.

- What are the dosages of polypodium that are useful and are there any side effects? - Yeah, great question. So there's been a wide variety of doses investigated, anywhere from 50, 100, 240, 480, generally- - You said 1500? - No, sorry, 50 milligrams, 100 milligrams, 240, 480. Somewhere in the, between 50 and 480 milligrams is what's commonly used.

The most common side effect can be a little upset stomach if you can't tolerate the plant for whatever reason. - It's taken daily? - It's taken, you can either take it daily as a method of preventing premature photoaging and pigmentary change, or you can take it as an as-needed, an hour before you get sun to shield you from the sun.

The other thing that it helps prevent that some sunscreens cannot, particularly the chemical sunscreens cannot, is the effects of visible light. So there are certain skin conditions, the most common is melasma, which a lot of women have, it's I think the bane of their existence. It used to be called the mask of pregnancy.

And melasma is something that is very sensitive to both UV and visible light. Chemical sunscreens don't do a good job blocking visible light. Polypodium has been shown to help block the effects of visible light as well, which makes melasma worse. It's this discoloration that we see mostly in women, usually after pregnancy or women who are on birth control.

It is really challenging to treat. And sun protection is the first line, like diligent sun protection. But we found that supplementing with polypodium enhances this and makes patients' treatments more effective. - Interesting, and you mentioned Sun Powder as a potential, that's a brand name? - So yes, Sun Powder is a brand.

It's a product that I helped formulate with one of my colleagues over at Harvard, who's a laser and aesthetic dermatologist to Harvard trained. And this is something that we came up with when I was up at Stanford. And it's a supplement dedicated to skin health, and it does two things.

I take it daily myself as a single scoop. It helps reduce your skin cancer risk, your non-melanoma skin cancer risk by up to 30%. And the data was published in the New England Journal of Medicine in a phase three randomized trial for one of the ingredients. The other ingredient, obviously, is polypodium.

And I take that one to prevent sun-related changes, but also help reduce my risk of burning. Often when I personally find the need for sunscreen, it's when I can't apply. I'm always at the water, I'm swimming. My son, he's seven, he races on a swim team. I cannot get this kid to reapply sunscreen.

So this is a supplement that I give him. And it took us several years of formulation and testing, including MED testing, which is minimal erythema dose testing to come up with. It's easy over the counter, and it's one of many supplements that contain polypodium. I just like it 'cause it's a single scoop and I mix it into my morning drink and I'm done.

Terrific. - I think we both agree that the mineral-based sunscreens are going to be the best option of the ones out there, if one is at all concerned about some of these chemical components in chemical sunscreens. - Yeah. - Absolutely. - Fair enough. - Absolutely agree. - Yeah, so within that category, are there particular things to look for?

I'm not necessarily trying to aim for particular brands here, but given that I have no relationship to any skincare products, I would just like to know which ones to look for, or will any zinc oxide and or titanium dioxide containing sunscreen, provided there are no chemical components in there, besides the inactive ingredients, of course, will any suffice?

Because in that case, people can just shop for cost or availability. - Yeah, so I tend to take a pragmatic approach in this. My recommendation is a brand that you will use, because if I recommend a brand and you don't like it, it doesn't feel good or smell good, you're never gonna use it and it's a waste of your money and time.

So number one, any brand that is mineral-based is fine. What you're looking for is broad spectrum coverage, which almost all mineral-based sunscreens provide. Broad spectrum meaning UVA and UVB. And we know these two UV forms do different things in the skin. We know that UVB is more implicated in redness and some early skin cancer changes.

We know UVA is linked to premature photo aging and certain melanomas. So you want something that provides broad spectrum coverage. You're looking for a number, the SPF we talk about. You're looking for a number above 30. Why 30? Because every study that looked at defining the SPF required you to put a certain amount on the skin.

Generally, it's an entire shot glass worth of the product on sun exposed skin. Most of the time in real world practice, people don't put on that much. They put on maybe half that. So what you're really getting when you buy something that's SPF 15 is like an SPF of eight.

So if you're looking for something that provides protection, SPF 30 or greater is higher. Higher the zinc concentration, the better it protects against UV invisible light. The chalkier it may go on. So that's kind of where you find that balance. That's actually where the chemical sunscreens came about is the cosmeceutical industry finding things that felt nicer on the skin so that people could put makeup on without that grainy chalkiness.

But in doing so, we ran into some issues. - What are some, if any, of the concerns that some of the components in chemical-based sunscreens can cross the blood-brain barrier? - It's not unjustified to think that. They are organic phenolic compounds. They are hydrophobic, they're lipophilic, meaning they can cross membranes very easily, which is why they run into this endocrine disruption and some nervous system dysregulation.

Whether that's been validated to be problematic in humans has yet to be seen, but at least in vitro studies in certain animal models, we see this. So when you apply a certain concentration, and with that 2020 study that showed that we're seeing it in the blood at levels that are 200 to 500 times the upper limit of normal as defined by sunscreen criteria, now we have to scratch our head.

Where is this circulating? Where is this going? Are we collecting it in our adipose tissue? If we're collecting it there, we may be collecting it up here. We may be collecting it in the nerves. So it's a really fascinating world to see where we're going with these. And in fact, the 16 most common chemicals that in '99 were everywhere, from spray sunscreens and bottles and things like that, are now being defied as, hmm, question mark, maybe not safe by the FDA, the very company that regulates it.

- Another call for the mineral-based sunscreens just as a, you know, why take the risk? - Or even, you know, shade hat clothing. You know, if you're really worried about putting something on in absorption, you get excellent protection by natural barriers. - This seems like a good time to shift a little bit of our attention to nutrition and the gut microbiome.

Now, this is an infinitely large topic. We could spend several episodes discussing this, but if you were to provide us some of the, kind of like major takeaways as it relates to nutrition and skin health, nutrition and skin appearance, gut and skin health and appearance, what would those be?

- So there is an incredible connection between the gut microbiome and skin health and the skin microbiome, of which we're only now just understanding the gravity, the extent, and the connection. We know from many studies, many elegant studies, a lot of studies done out of my colleagues' labs up at Stanford, that modulating the gut microbiome affects inflammatory conditions of the skin.

Meaning, if you control the dysregulation of the gut microbiome, if you have an anti-inflammatory dietary habit, actual skin disease decreases in intensity and severity, psoriasis, eczema, acne. And this is not just subjectively, it's measurable and quantifiable and reproducible. So the connection is fascinating. Now, how we modulate it, that's the unknown.

We know in many different studies that some patients' gut microbiomes are wildly fluctuant to what they do from their environment in terms of dietary habits, antibiotics, things like that. Some people's gut microbiomes are rock solid, nothing changes them. And deciphering whose will benefit from what is the hardest part.

In terms of nutrition overall, obviously everybody's told you this since the dawn of modern medicine, is a well-balanced diet is good for everything. Unfortunately, in the 21st century, there are a lot of diets. There are a lot of fad diets, there are a lot of restrictive diets. And that's where we see nutrition play an important role in both appearance and actual skin disease health.

And there's so many different avenues to discuss this. Things like dietary habits and changes for acne. Things like dietary habits and changes for anti-aging. Things like dietary habits for rash disorders like psoriasis and eczema. It's so much to explore. - So my understanding, and we'll get into this more as it relates to acne, is that patterns of eating, either content, food volume, that is caloric load, et cetera, that increase insulin and things like mTOR are sort of pro-acne.

They're gonna aggravate or increase acne. Whereas the things that tend to lower circulating blood glucose, insulin, and reduce inflammation tend to be kind of anti-acne, or sort of pull in the other direction towards reducing acne load. But if we were to just step back and say, okay, the typical person who wants to have the healthiest, best-appearing skin, who's not dealing with any specific issue, 'cause we will get into those specific issues, can we say they should eat a vegan diet, a vegetarian diet, is it okay to be an omnivore?

Some people are on the extreme of this kind of carnivore-type diet. Some of those people actually report elimination of certain skin conditions. I don't know, I've never tried one of those extreme diets, but you hear this, but again, you hear a lot of things. So it seems to me that the relationship between keeping the gut microbiome healthy and ingesting sufficient amounts of fiber is pretty clear.

The relationship between keeping the gut microbiome healthy and overall, that is, systemic inflammation low is pretty clear, and that eating foods that are mostly unprocessed or minimally processed keeps inflammation on the lower side, as opposed to eating more processed foods. But, you know, assuming you, would you agree or disagree with me on that?

Feel free to disagree, please, yeah. So assuming that that's all true, is there any evidence that the ingestion of specific foods can make skin healthier? Like, you'll see this stuff, like, oh, you know, if you have two cups of blueberries a day, your skin is going to be healthier.

Or is all of that indirect by virtue of specific micronutrients that are in those foods? - So there's a lot of layers to unravel on this. So if you're gonna pick one simple diet for optimal skin health, it's a high-protein, anti-inflammatory diet. So high-protein, animal-sourced proteins, fruits and vegetables, based on your ability to tolerate the fibers in the fruits and vegetables.

Things that are inflammatory are inflammatory for two reasons. One, the glucose-insulin pathway, but number two, the bacteria in our gut process and release byproducts of metabolism of certain things. And those byproducts, basically their digestive products, can be very pro-inflammatory. So often you hear these anecdotal stories of I eliminated tomatoes and my psoriasis got better.

That person may have had an inability to tolerate tomatoes because of their gut microbiome's ability to digest the lycopene or whatever it is. We do know for certain that anti-inflammatory diets do improve skin health that are measurable and seen in clinic. So absolutely high-protein, a complete protein. When I say complete protein, tends to be animal-based products, eggs, meat, chicken, fish, less so plant proteins just because of bioavailability and complete amino acid profiles.

You want a high-protein, anti-inflammatory diet. That's number one. In terms of what you can introduce to your skin to improve one or two parameters, I don't think that's real. Why I bring this up, we see a lot of talk and you've had a lot of people discuss collagen, for example, and this is an incredibly popular product in the skin world because its claim to fame is it does everything, keeps you looking young, keeps your skin healthy, et cetera, et cetera.

Well, we know collagen is essential to our skin health. Literally, it's what our dermis is made of that give us our suppleness, our youth, no wrinkles, you know, things like that. Collagen is made of three amino acids, glycine, proline, and usually hydroxyproline or hydroxyl lysine, okay? Those three amino acids are non-essential amino acids, meaning your body has the ability to synthesize these from sugars and fats that it eats.

So collagen supplementation is not an essential protein, unlike animal proteins, which provide all 20 amino acids, including the essential ones your body cannot synthesize. Now, you may ask, okay, well, I see all these studies that suggest collagen supplementation improves skin health, skin appearance. There's several reasons for that. I don't think it doesn't.

I think there is some benefit. The question is what are the confounding variables to this? Were the people in the studies on restrictive diets because they were thinking about beauty and aesthetic? Were they restricting patterns of food, dietary food, things like that, in which they weren't getting a sufficient amount of protein source to begin with?

So when they supplemented, we saw improvements in their skin. And a lot of these studies are patient recall or patient questionnaire studies, in which there is inherent subjectivity and confounding variables in this. When people take an intervention that says, hey, you may look better, or this may improve the appearance of your skin, not only do you have a placebo effect in saying, yeah, I do look better, you may also do other things during your day, change your behaviors and lifestyle to fit the goal that you subconsciously want.

So that's one. Number two, there is a component in, for example, collagen supplementation that is forgotten about quite a bit. And that's the increase in blood osmolality. And I learned this in the fitness world. I was really big into fitness in college, and it was my escape from life stressors.

And we found that people who supplemented with any powdered protein source, it doesn't matter collagen, albumin, whey, and more so with people who supplement with creatine, that there is an increase in blood or plasma osmolality. So the solute concentration increase in the blood, which draws water in. That's predominantly how things like creatine make you look bigger.

And I know we're going a little bit on a tangent, but one of the reasons the way collagen works is your blood osmolality increases, you draw a little bit more water into the vessels, which plumps up the appearance of the skin. So there is a hydration component from the water draw, and this is measurable.

You can draw a patient's blood after consuming collagen protein, whey protein, and see this spike in plasma protein. So there's that component as well, which is not truly a benefit, but it's an aesthetic benefit. Why that tends to be a problem is sometimes people supplement with collagen end up actually having high blood pressure and they're otherwise healthy.

And this was something that we saw in the fitness world a lot, is that young college athletes, high school athletes that would come in, they would otherwise be completely healthy and would be running high blood pressures. If you took away their protein and creatine supplementation, their blood pressures dropped.

- Interesting. - And it's really fascinating stuff. And I used to work out at UCLA with one of the professors of Phi Psi, who was a really big dude. And we worked out together and we did all these studies and looked at young, otherwise healthy people. So that's one component.

The other question is, do any of these food changes actually quantifiably increase skin collagen density, skin elastin density? There's no evidence that taking these things will traffic, or meaning will go to where you want them to. It's kind of silly to think if I drink this, it's gonna go into my stomach, go into my intestine, be absorbed and then know to go exactly to my cheek.

Usually it doesn't occur that way. And when we've looked at histologic comparison studies, the data is equivocal. Some studies have shown a slightly increase in collagen density and you wonder, are those patients one that are on restrictive diets to begin with? And then there are some studies that have shown there's really no density change in collagen and elastin.

So the supplements really don't actually make a physical difference. Now the other question is, is that study too short of term? How long do you stay on these? Data is wild and there's a lot to understand, but we do know high protein, complete proteins, anti-inflammatory diets, absolutely critical for skin health.

- I guess the most direct question is, do you yourself consume collagen proteins in a supplement form or make it a point to eat things like bone broth, which contain high percentages of collagen? - Great question. I do supplement only in sun powder, which is my daily supplement. It contains bioactive collagen peptides.

Aside from that, I think natural sources are better. So my wife cooks a lot at home, bone broth, beef bone broth, chicken bone broth, a lot of animal meats. My diet tends to be more in the, I guess old school, you'd call it Atkins or keto diet, where I eat a lot of proteins and mostly fruits and vegetables.

I'm not very restrictive, but I know that's what's made the biggest difference. I know that if I go on a sugar binge in a few days, I'm breaking out, it's like clockwork for me. Some people are not as sensitive, my body is, and that's where the personalized medicine comes in.

- Is there a role for omega-3 fatty acids like fish oils and things of that sort for skin health specifically? - Yes and no. Yes, there is some evidence that omega-3 supplementation and tends to be better in fish form than non-fish formats, but omega-3s tend to be anti-inflammatory. So there's an improvement in skin health because of that.

One thing we do see is they thin the blood. So people tend to bruise a little bit more. So actually in my practice, I have people stop omega-3s before any sort of surgery because they bleed more. - What about some treatments that are known to be beneficial for the appearance and health of skin that people are not as aware of, right?

Because I think people who are concerned with their skin health and appearance, they think about sunscreen and we've learned a lot about that from you, but what are some things that really work to improve skin health and appearance that perhaps require a visit to the dermatologist, but that you don't hear enough about?

- Yeah, so two big categories. So we know the skin turns over, right? It turns over every 28 days. So in theory, if you keep turning the skin over, you can get rid of those mutations that occur in the skin that's stacking up and hope to bring out more vital, youthful skin that's not just appearing vital, but actually biologically healthier.

And there's two categories of things you can do. The first is the family of retinoids. Amazing medications, amazing drugs, been around for 50 years. They come in oral form and topical form. And these increase the time or they shorten the time, they increase the skin turnover from 28 days to somewhere between seven to nine days.

And in doing so, they've been shown to decrease skin cancer and pre-cancer formation. They've been actually shown to grow new collagen. They've been shown to increase elastin and appearance. And this has been histologically verified in study after study, meaning we take a biopsy of the skin, have them start a prescription retinoid, re-biopsy the skin and stain it for collagen or elastin, and you see a marked improvement.

It's every dermatologist's well-known tool. And for some reason, it's still not well-known in the population. Its original indication was for acne and still is first line for acne, because what it does is it dries out the oil glands. But in doing so, it also helps repair skin. So I recommend every single person to be on a prescription-strength retinoid, which is different than over-the-counter retinol.

And there's a lot of confusion, and I think the confusion is intentional in the cosmeceutical world as to why this is, but everybody should be on a prescription-strength retinoid. Usually topicals is all you need. The most common are things like tretinoin, adapalene, or tazerotine. And there's oral forms. The most common is Accutane or Isotretinoin, and to a lesser-known drug called Acetretin or Seriatane.

And I usually reserve that for my high sun damage skin cancer patients. It really makes a difference. But I'm gonna touch back about retinol versus retinoids. So many, many years, we studied retinoids. The way retinoids work is they're actually, and they activate transcription factors, they're nuclear messaging hormones. So these compounds bind retinoic acid receptors, and they activate the transcription of certain genes.

One of the genes we know that it can affect is the sonic hedgehog pathway and some of the embryologic genes. Why that's important is when we first studied retinoids in oral or cream version, we noticed that these can affect the development of a fetus, and they can be passed through breast milk and through sperm or semen.

So because of this issue, the FDA regulated it very tightly. And it's pretty regulated worldwide because the effects are devastating, missing arms, missing legs type of birth defects. Because the medication was so effective and we saw an improvement in both quality and appearance of skin, the cosmeceutical beauty world said, oh, okay, this is awesome.

We need to figure out a way to get this on the shelf, but not be a prescription. Out came retinols with an OL, which is the inactive version of retinoic acid, which is retinoids. And what has to happen is retinol needs to be converted in a two-step process to become active retinoic acid.

Otherwise, it's a completely inactive prodrug, which is sold over the counter at concentrations that are not biologically active. That's how cosmeceutical companies can get away with prescribing this for people of childbearing age. In my opinion, if you want a retinoid, get a prescription for it. The over-the-counter stuff is not very effective, if at all.

The shelf stability, many studies have shown that almost all retinoids over-the-counter, retinols over-the-counter are basically unstabilized by one year. So you don't even know what you're paying for. The prescription is easy to get. You can see pretty much any dermatologist, and it's the only version that's truly effective. So everybody should be on it.

Protects your skin, keeps you looking young, reduces skin cancer risk, grows new collagen. Literally the only consequence is that when you first start, your skin may be a little bit red or peely as the skin acclimates or turns over. Other than that, nothing. - Why do you think, given the immense interest in skin appearance and health, that we don't hear more about this?

- Because, that's a great question. So we hear so much about retinol. Every magazine you open that has anything, you'll see like intensive night cream, intensive eye serum, regenerist eye repair, and all of them have retinol. None of them have retinoid or tretinoin for many reasons. Originally it was made for acne.

And the patients that came in to get them for acne were not necessarily in the same line of thought of premature aging and longevity. - This would be things like Retin-A. - Yeah, Retin-A, exactly, or Accutane, or Differin. These are the brand names for these products. So there was a disconnect between the people seeking the anti-aging effects and the people getting it as a prescription.

That's one. And number two, as soon as cosmeceutical companies figured out a way to market over-the-counter inactive versions, that went haywire. So you can Google retinol and there's a million things. When you Google tretinoin, you only hear about acne. So there's a little bit of a disconnect, much like all in medicine, between what docs know and think the population knows and what the population actually knows.

But that's the one thing I think we've been doing a great job on in modern day social media is advocating for these medicines. Now, that's one realm of things that you can do to absolutely improve the quality of your skin, long-term health, appearance, actually revitalize the skin. Then there's a whole set of procedures that can be done that have been shown to improve not only the appearance, but actual biologic health.

So that's where we fall into the laser world. And somebody who's been in photobiology, albeit a slightly different realm, you know the effects of light and the incredible changes that it can have in biology. Most of what we understand for lasers in medicine came out of dermatology studies. A lot of the understanding of laser biology came out of the Wellman Institute over at Harvard, where many of my colleagues are.

And we now know that certain laser devices, certain resurfacing devices, not only improve the appearance of your skin, clinically, they reduce your risk of skin cancer by 20%, maybe greater. And even more amazingly, is when you do microarray gene studies, they actually activate the genes of more youthful, healthy skin cells that were quiescent as we age.

So there's genetic verification, clinical verification, and aesthetic verification. These things are awesome. Now, laser is a big umbrella term. Some of the devices we use are not lasers. They're actually light, broadband light, or intense pulse light. Some of them are lasers. Some of them are ablative. Some of them are non-ablative.

And we get into the nuances of these things, but there are a few lasers that have been shown to make these dramatic differences. So if you're interested, I mean, see an expert. - So this would be go to your dermatologist, ask for some, is it laser resurfacing? - Yeah, yeah.

So laser resurfacing, it tends to be, and what's really popular, there's two forms of laser resurfacing. There's what we call non-ablative, meaning it doesn't burn or vaporize the top layer of skin. And then there's ablative resurfacing, which vaporizes the top layer of skin. Obviously, ablative ones are much more aggressive, much more effective, a lot more downtime, and a lot riskier, because you're literally peeling the face off or any part of the body.

And it regrows without any scarring. That's also another beauty of the skin is you can literally peel it off entirely and have it regrow as if nothing ever happened. - So people have this done once a year or so? - Yeah, for ablative resurfacing, it's like once every five years or so on.

It's pretty dramatic. - And how long is the downtime? - For ablative resurfacing, two weeks. Usually two weeks, you're pretty raw and sore. It's fallen out of favor in most big cities because of the downtime and the inherent risks, but it's still used in the right patient. Non-ablative resurfacing, meaning it doesn't vaporize the top layer, but drills holes into the dermis and targets certain parts of the epidermis without causing burn injury, that's become much more popular because the downtime is markedly less.

People can go back to work and enjoy their activities. While having pretty much the same benefits, albeit a little bit less than ablative lasers, these we generally recommend annually or biannually, depending on what you're trying to target. A large Harvard study just came out that showed that non-ablative fractionated laser resurfacing, particularly with a device called Fraxel, actually cuts your skin cancer risk by 20% because it eliminates those mutations and gets rid of those cells that had been collecting the stuff.

It's amazing. - How is this different than exfoliating skin? Like if one were to just try and scrape away some of the dead skin through some, you know, semi-vigorous buffing of the skin with like a sponge. I've never done either of these procedures. Like I said, my skincare routine is very basic.

It's the unscented dove soap. The shower once or twice a day and- - Your skin looks great, so keep doing what you're doing. - I mean, I feel pretty good. I mean, I think, you know, sleep seems to play a significant role for me. I do get probably a bit more sun exposure than most people.

I'm conscious of checking for skin cancers and we'll talk about that because those do run in my family. But, and I try and eat right and exercise right. Haven't consumed much alcohol in my lifetime. - Well, your skin will tell you if something's wrong. So that's the first line.

Now you talk about, you know, dermabrasion or microdermabrasion, the good old St. Ives apricot scrub that every dermatologist, you know, frowns upon. But ironically, I use myself after a heavy workout at the beach and I'm all greasy, but don't, you know, don't get mad at me for using that stuff.

The depth is key. So when we do microdermabrasion or some sort of dermabrasion, the only thing we're really scraping off is really the stratum corneum, which is the highest layer of skin cells that don't even have a nucleus. They're dead skin cells. That's all you're scraping off. Whereas lasers target through the epidermis and into the dermis and you control for that depth.

And what you control for is the amount of heat energy delivered to that depth to target a certain thing. So in theory, what you describe in terms of dermabrasion is the same premise the old school ablative lasers do. They just fry everything off and you grow new skin. And in frying everything off, it fries off sun damage, wrinkles, pre-cancers and skin cancers.

But in doing that, you're a bloody mess for a few weeks. Not popular for many reasons, but very effective. We did a ton of this at Stanford and we did a ton of the other one at Stanford. In my practice, I do a lot of laser work as well.

The non-ablative stuff picks and chooses. That was the beauty of learning about laser and photobiology is how we target a certain structure and avoid damaging all the other ones. That's the theory of selective photothermalysis that came out of Rox Anderson's lab at Harvard. That was the game changer. We can now pick any appendage in the skin and find a way to target it and leave the rest undisturbed.

So if you have broken blood vessels, you decide to use BPC-157 and it worked great and the blood vessels started to grow and you're like, I don't like the look of them. There is a laser that targets solely blood vessels. - Is that the IPL laser? - IPL is okay.

IPL stands for intense pulse light. It's somewhat effective, but not very effective. The gold standard is what we call the pulse dye laser or the V-beam laser. That is a 595 nanometer laser that targets oxyhemoglobin. - I've had that actually because I had an angioma. - Yeah. - Had it three times and the third time they hit this thing, it went away, but not without a very significant bruise lasting almost a month.

I mean, it was pretty dramatic. - Never done it. - Right, but it did eliminate the vessel. - By any means necessary, right? It just nuked the skin. - So as long as we're on the topic of photobiomodulation, what about red light, near-infrared light? Is there any evidence that it can benefit skin health and appearance?

Nowadays, you can find masks that will emit red light. Some people will purchase red lights. They stand in front of. - I think they're very effective. I think they work great. The question is to what extent is that improvement objective and measurable and what extent is subjective? That being said, there's a lot of evidence that shows that red light therapy improves vascular flow in the skin.

We use it for things like hair restoration, post-procedure recovery, improvement in skin health after UV damage. We actually found a recent study that looked at red light therapy and irradiating mice. And if you pre-treat the mice with red light therapy before they get UV exposure compared to controls, the pre-treated group had much less of the changes with UV exposure.

So very fascinating stuff. How it works, uncertain. We think a lot of it has to do with increased vascular flow, which is why a lot of times we recommend it for post-procedure. We recommend it for hair regrowth. There's some evidence that if you increase blood flow to the dermal papilla of the hair, it grows new hair.

That's how minoxidil or Rogaine works. But I like it. I think it's a great product, great group of products or devices. As a standalone, uncertain as to how effective they are. And one of the reasons of the heterogeneity in the data or like so much difference is there's no regulation in terms of the energy, the density of light, the type of light, the duration of treatment.

So some devices have high wattage, high energy output, high density of lights. They may be more effective than its equivalent counterpart. And until that gets defined more uniform in accessibility, I don't know which device to recommend. I obviously have preferences one way or another, but there's so much on the market that's marketed as red light that is not effective and some stuff that's really good.

- So probably looking for something that's at least endorsed by dermatologists. - Yeah, yeah, absolutely. - And I should say here, I have no angle into this. These masks that emit red light, I don't have any business relationship to them. So that's not why I bring it up. I was just very curious.

I see them in my Instagram feed, probably by virtue of doing public facing health and science information and my interest in light. What about, oh, yes, excuse me. - I was going to say the panels tend to be much higher in energy, much more effective. And most of the studies have looked at the big wall panels.

The battery powered face masks just aren't powered enough to have much improvement. We do see some improvement when red and blue is used together, mostly for acne prone skin, because blue light alone has some antimicrobial properties. So when used in conjunction, you can get some improvement in actual skin illnesses.

But the masks alone with just red light, most of them are not powered enough. They don't have enough energy, but there are some that are good. The wall panels tend to be better. - Thank you for that. And full disclosure, I was accurate in saying that I don't have any relationship to any red light masks companies or products, but this podcast is sponsored by Juve, which makes medical grade panels for red light and near infrared light.

And I do own one of those and I use, I have a small portable one I use and then I have a panel I stand in front of. So that includes my face and then I'll turn around and do a whole body couple times a week. Juve is a good company.

It's been around for a while. And most of the experts in laser and photobiology agree the panels are the way to go if you want red light. - It's interesting when people see and hear about red light and near infrared light therapies, I think a lot of people think, "Oh, this is kind of like next stage biohacking." But there was a Nobel prize given for photobiomodulation for the treatment of lupus in the early 1900s.

So this is a longstanding thing, the use of light of particular wavelengths or combinations of wavelengths of which red light and blue light are, of course, in order to target different layers within the skin to get some desired effect. - Yeah, light has been around for a long time.

I have a phototherapy unit in my practice in which we use narrow band ultraviolet B light to treat conditions like psoriasis, to treat conditions like vitiligo. There's a very strong immunomodulatory effect of light on the skin. It actually suppresses overactive immune activity. It can help increase vascularity in the skin.

It can improve blood flow. So depending on the wavelength you pick and where it overlies on the absorption curves makes a big difference. It's interesting that we talk about light and as a skin cancer surgeon, this has always been interesting to me in that we use UV light to treat certain conditions and we assume UV light is purely pathogenic.

And I don't think that's the case. And why I bring this up is one of the most common things we use like light therapy for is patients with vitiligo, which is this autoimmune condition in which your immune system attacks the cells that produce our skin color. And the standard treatment is certain creams that suppress the immune system in the skin, phototherapy, eczema laser, which is a UV laser.

And then now the new world of immunotherapies by pill form, the Jack inhibitors have made a huge difference. But if we thought, and I go back on this tangent 'cause the more we think about it, the less we know. If we think UV is truly deleterious, then patients with vitiligo should have an higher incidence of skin cancer.

And in fact, the opposite is true. They have a lower incidence of skin cancer even when you match them for amount of UV exposure over time. So it goes to tell us that there's so much about light and skin we don't understand, so much about sun and UV and skin we don't understand and an incredible component about our skin's immune system that we're only now figuring out that play an important role.

Patients who have transplants, for example, transplant patients in the early '90s, the number one cause of death for transplant patients that was not related to their transplant was metastatic skin cancer. And this was in patients who were strictly sun protected. So we talk about biology, photobiology, LED, UV, and skin health, and there's so much we don't know as we gather more data and look at populations and cohorts.

So I don't know why I brought that up as a tangent, but. - No, I think it's a very relevant tangent because the relationship between immune system function and skin is very clear. And these conditions that you're referring to, vitiligo, acne, psoriasis, eczema, et cetera, have interesting relationships to the immune system.

So that's actually a perfect segue for what I'd like to talk about next. - Sure. - So let's start with psoriasis. - Yeah. - What is the story with psoriasis? What is it? What can make it worse? What can make it better? - Psoriasis is like the quintessential skin condition.

I have it myself on my elbows and knees. And for about 100 years, it was thought to be a problem, a rash that is caused by too much skin turnover or excess skin proliferation. And for 100 years, we treated it the same way. We gave medicines that basically took the skin off, what we call keratolytics.

We found that that wasn't very effective. And some people can be hospitalized and it can be life-threatening if psoriasis involves the entire body. It usually looks like red patches or plaques with kind of a silvery scale on the surface and starts usually elbows and knees or the scalp, but can involve pretty much the entirety of the body.

And what we found in the last 30 years with a lot of elegant studies and a lot of very, very nice basic science research is that it's actually due to overactivity of our skin's immune system. So there's overactivity of certain interleukins, which are these messengers that our immune cells produce, that makes the skin turnover faster than it should.

And this epiphany was remarkable because we found that instead of targeting the skin, we can target the immune system and we can eradicate or treat psoriasis entirely. And in the '90s and early 2000s, that targeting was very crude. It was a very umbrella approach. We suppressed the entire immune system and ran into the consequences of that.

So medications that we gave for that increased risk for infections and skin cancers, et cetera. Now we have amazing drugs that target one or two molecules, messenger molecules of our immune system and clear up people's psoriasis. I mean, we have drugs now you take three times a year and you could have head-to-toe psoriasis and be completely clear.

It tends to run in families. There is a very strong hereditary or genetic component to it. And it tends to be associated with arthritis, psoriatic arthritis. So psoriasis is like the quintessential skin condition that people see dermatologists and even rheumatologists for. - So these drugs that target these specific interleukins seem like the most direct way to treat psoriasis.

Some people, for whatever reason, have an aversion to prescription drugs. - Yeah, yeah, yeah. - I'm not necessarily one of those people, but I, like everybody else, would like to know what we can do to reduce symptoms of things like psoriasis without having to "take anything." - Yeah, I should probably backtrack.

So psoriasis obviously comes in severity. There's mild disease, which majority of people have. There's moderate and severe. And generally speaking, the most common things that we treat mild psoriasis with is creams and lotions, moisturizers, sometimes low-potency topical steroids or high-potency topical steroids, and then things like keratolytics, like salicylic acid, that take that excess scale off.

We also know that there, because it's an immune inflammatory condition, that diet plays a big role in improving mild or moderate cases. And we also know that weight loss plays a very big role in improving the appearance of psoriasis. So as we lose weight, as there's improvement in insulin resistance, and as we transition diets and lifestyles from inflammatory to anti-inflammatory, psoriasis tends to clear without any intervention needed, without any medical intervention needed.

If there's still continued rashes and skin activity, then you'd look at topicals like cortisones, emollients like Aquaphor and Vaseline, things with some sort of acid or a retinoid to get rid of that excess scale. That's the fundamental cornerstone of treating psoriasis. And then when it gets bad, we talk about additional pharmacologic interventions.

Also, interestingly, one of the earliest conditions in which phototherapy was used is psoriasis. We know that when we shine UV light on the skin, that it suppresses the skin's immune system and clear psoriasis. And that's an excellent way to treat it without pharmacologic intervention, without any creams, pills, injections, or otherwise medication.

It used to be used in the Dead Sea. People would go lather in the mud in the Dead Sea and sit out in the sun. And that was the first crude way to use phototherapy to treat psoriasis. - That was my question. Since the sun emits UV, why not just get some additional sunlight exposure for psoriasis?

- So you can, most dermatologists wouldn't recommend it. I think it's actually not a bad thing. My psoriasis clears in the summertime and flares in the wintertime. The problem with pure sunlight is that it's a mix of rays, right? There's X-rays, gamma rays, which generally don't penetrate the atmosphere.

There's UVC, UVB, UVA, visible light, infrared light. So that heterogeneous light, some have no improvement in psoriasis and some have great improvement. So we were able to figure out which wavelengths make a big difference. And it's around the 311, 312 nanometer range. But sunlight does clear people's psoriasis up.

That's why we see in Northern latitudes where there's less sun intensity, the incidence of psoriasis is markedly higher than equatorial latitudes. And patients will say their psoriasis gets better when they're on a beach vacation. When they go back home, their psoriasis flares. There's also some component with vitamin D as well, but I think that's just secondary to the lack of UV exposure.

- What about vitiligo? This is something I did not cover in the solo episode about skin health, but I got a lot of questions about vitiligo, of course, being this typically patchy, non-pigmented regions of skin that you said is at least some cases are related to the immune system.

These people get skin cancers less often, is that right? - Yeah, so vitiligo is autoimmune, meaning your immune system is attacking itself, depigmentary skin disorder, meaning it's a condition in which your immune system attacks and kills the melanocytes, which are the cells that produce our skin's color. And we've found that it's an autoimmune condition from many basic science and elegant studies.

It's also very closely associated with other autoimmune conditions. So patients tend to also have atopic dermatitis, autoimmune thyroid disease, autoimmune anemia. There's some sort of immune dyscrasia that involves vitiligo patients. And what happens is the immune system at first paralyzes these cells with immune activity attacking them. And over time, these cells no longer survive and die off.

The cornerstone in treatment has always been some way to suppress the skin's immune response. When most of the time vitiligo tends to be focal, single areas or segmental. Unfortunately, in certain cases it can be whole body or completely depigmenting. Very uncommon, but we see this. We treat it by doing things that'll help quiet the immune response in the skin.

So topical creams, topical steroids, et cetera, topical calcineurin inhibitors, which are non-steroidal anti-inflammatory medications. We also use certain wavelengths of UV light to treat this, eczema laser at 308 nanometers, UVB, UVA. And then the renaissance in vitiligo has happened in the last three or four years with the identification of JAK inhibitors, which are these drugs that block the Janus kinase pathway.

And we found that the JAK stat pathway plays a really important role in autoimmune mediation of melanocyte death. So new creams and actually oral medications have come out for patients who have very refractory vitiligo. The immune component is very fascinating because understanding immune biology and the immune system's effects on skin health comes from studying these patients.

When patients have vitiligo, they lose all of their color. So you would assume that they're much more susceptible to sunburns, which they are. But when you look at incidents of skin cancers, they have a significantly lower incidence of skin cancer. And this is because of the immune phenomenon in immune surveillance of cancer.

And that occurs throughout the body, but the skin is a model platform for this. What happens is your immune system surveys for mutant changes that occur, whether it's UV related, et cetera, infection, toxin, whatever. And patients who have vitiligo have overactivity of these immune cells and over surveillance. So they are able to clear a lot of these pre-cancerous changes before they form into something.

So that played a big role in not only understanding how to treat vitiligo, but some of our new medicines, actually the medicines that won the Nobel Prize in 2018 for treating melanoma came from understanding immune activity and cancer pathogenesis. - It's fascinating. Again, speaking to the fact that skin is far more than just this protective outer sheath.

It's a reflection of so much that's going on internally. And we know that intuitively also by observing others. I think this is one of several ways that parents can communicate well with their children or their children with their parents rather, in terms of how they're feeling prior to language.

You know, they'll look at their skin, their stool, obviously fussiness and mood and those things too. But we seem to have developed an intuitive understanding that a shift in the kind of like tone of the skin or some other features of the skin signal to us wellness or lack of wellness.

- Yeah, the skin's a biosensor. The entire skin, hair, nails is a biosensor. So you can utilize the skin as the first barometer of illness. I mean, from acute illness to chronic illness, acutely you can see changes in just like looking pal, you know, with pallor, looking ghastly, things like that.

But chronic illness as well. You know, when you used to go to the pediatrician and they would do this to look at your eyes, what they were looking for was the color of the conjunctiva. If it was white or pale, they knew you had iron deficiency. You know, when kids get hand, foot, mouth syndrome and they have a high fever, they lose their fingernails.

When college students are stressed out, they lose their hair. The body's amazing ability to tell you it's under stress is shown in the skin, hair and nails. What it does is it says, why am I wasting energy producing something that is not necessary because I'm fighting something else? Let's just shed this.

And you can tell right away. I mean, we used to in clinic when I'd see, you know, medical students or college students come in, I knew it was finals week. They'd come with clumps of hair. And as soon as finals week passed, usually took a few months, their hair grew back.

It's awesome. The skin's a really cool biosensor and you can tell a lot. - It is so cool. What about acne? - Yeah. - Acne seems very common, you know, as we progress through puberty, there seems to be more acne. Sometimes it's transient, sometimes it's not. - Yeah. - What are some things that people can do to prevent or reduce acne?

- Another quintessential derm problem that is affects so many people. Acne tends to be a condition that is bimodal, meaning we tend to see it in adolescents. We tend to see it in 25 to 35 year olds. And for the unfortunate group of people that bridge that gap, we see it anywhere from 12 to 35.

Acne is a condition that's usually seen by pimples. You know, what we call blackheads or whiteheads, zits or boils. And it's thought to be caused by three important things. It's an overproduction of sebum, which is the oily stuff that comes out of your skin. And that's dictated by your hormones.

Your hormones will increase the output of sebum. And that usually occurs in puberty, but can also occur if you're taking medications like prednisone, cortisol, testosterone, anything that is a hormone driver. So sebum is the first cause. Sebum is the food for the bacteria that cause acne. So as there's more food, the bacteria proliferate.

And in proliferation, it recruits an immune response. Your immune system says, "Hey, there's a little bit too much of these organisms. "Let's go and take care of them." That's where you get that red zit. So in treating acne, you gotta treat all three components to get really effectively clear skin.

Somehow reduce the sebum, get rid of the bacteria, and calm the immune system down. That's done with creams, oral medications, a combination of both. Sometimes certain lasers can help eradicate the oil glands that feed the bacteria. But acne's a fascinating condition. Almost everybody will have it at some point in their life.

- Is it true that eating a diet that is of slight excess in calories, because it will tend to push the insulin glucose regulation system more into the positive as opposed to, let's just say higher levels of insulin and circulating blood glucose than one would observe at, say, maintenance calories or sub-maintenance calories that, you know, overeating a little bit could cause acne, that any foods that promote increases in glucose and insulin, so sugary foods, high glycemic foods, these sorts of things, can that actually increase acne, fried foods?

- So it's not the caloric deficit or the caloric surplus. It's the glycemic index or the amount of insulin response. So we know that high glycemic index foods will make acne worse. And almost every study that we've looked at in sugary processed foods will flare your acne. There's some component of that inflammatory response that not only drives even production and bacterial growth, but actually worsens the skin's immune response.

The skin's immune response is a little feisty when you're eating pro-inflammatory things. The other thing that I do hear a lot about is dairy. And there's this misconception that dairy causes acne. What we really see when we looked at a really cool study that was done out of Penn State is that it's not so much whole fat dairy products, but skim and non-fat dairy products that can make your acne flare.

And the reason for that is that usually in the United States, there's an emulsifier that's put in non-fat or skim products to give the same mouth feel as full fat. So people feel like they're getting the same without the calories. And that has a glycemic response. So it's usually sugary foods, non-fat skim dairy products that will make your acne flare.

- What about rosacea? I hear so much about this, and I'm going to assume that we can mark off at least one thing as clear, which is that alcohol can exacerbate rosacea, maybe directly, but certainly indirectly by impeding some aspects of the microbiome, disrupting sleep, rosacea gets worse. But what are things that people can do?

Do's and don'ts that is for rosacea. If it's mild rosacea, like excessively ruddy cheeks or superficial riding capillaries that seem to bother a lot of people. I know that it bothers a lot of people because they asked about this quite a lot in the questions when I solicited for questions.

- So rosacea, it's commonly known as adult acne, tends to come in four flavors. The first form is the redness form, what we call erythematotelangic tatic form, or the ruddiness, broken blood vessels, redness of the cheeks and flushing. That's by and far the most common form. There's also the papulopustular form, which is the pimple form, which is what we think about in adult acne.

There's also the fimatus form, which is the enlargement of the nose that kind of looks like toad skin. We used to think it was a sign of alcoholism or sailors or construction workers that would have these enlarged nose. We thought it was a product of their environment that's actually a form of rosacea.

And then there's ocular rosacea, which affects the eyes. By and far, the two most common that we see people in practice for is the redness form, redness and flushing, or the pimple form. You're absolutely right in that alcohol can contribute to it and worsen it for two reasons. One, alcohol itself is a vasodilator and acetaldehyde is a much more potent vasodilator.

So when you drink, you flush. Also chronic impairment of the gut microbiome and lifestyle changes that make you drink more probably will exacerbate your rosacea. But things that trigger the redness include UV light because of vasodilation, spicy foods, hot beverages, emotions, life stressors, all the things that make you flush.

What triggers the breakouts is a little bit different. And why that's important is how we treat them. So what triggers breakouts is thought to be both organisms that live on our skin, including bacteria and certain mites, but also immune dysregulation in our skin. That we don't really understand or just now elucidating how the immune system in the skin becomes dysfunctional to show those breakouts.

In terms of treating redness, we have some creams that are okay at temporarily blanching those vessels out, but they're not great and they're temporary. We don't have great treatments for them, but we have great lasers for redness. So when patients come to see me for redness or any dermatologist for redness, generally there's a discussion about laser destruction of those blood vessels.

When we talk about breakouts or pimple form of rosacea, we have excellent medications in terms of both creams and oral medications that suppress both the bacterial and mite growth as well as the immune response in the skin. So you kind of have to take a look at what form you have and what will be the best treatment.

- Eczema. - Umbrella term for what we generally consider as atopic dermatitis, or what used to be colloquially termed as sensitive skin in childhood. And that's a very prominent skin condition also dictated by the immune system, but in two forms. Eczema tends to be caused by three major prongs.

The first prong is a genetic barrier defect in the skin. So patients with eczema tend to have a microscopic weave of their skin that's not as tight as somebody without eczema. And that's usually defined by a gene called filaggrin. That's the first reason to develop eczema. The second reason is an environmental allergen or trigger that's able to get through these weaves easier because of this genetic change.

The third thing is an aberrant immune response to these triggers. So patients with eczema tend to have an immune system that responds a little bit more vigorously or overactively to the same environmental trigger, probably because there's more trigger getting in through the barrier defect than somebody who doesn't. So the cornerstone in treating eczema is treating these three things.

Why dermatologists make a big stink about moisturize, moisturize, moisturize for eczema is to seal that barrier with a moisturizer because we're basically putting the mortar back in between the bricks, which are the skin cells, to seal the skin off, to not allow the environmental allergen to get in. That's the first.

The second is to avoid environmental triggers. So fragrances, preservatives, seasonal allergies, pollens, things that trigger that immune response, we try to mitigate. Now, obviously trying to control environmental pollens is hard, but using things like we talked about earlier, fragrance-free cleansers, fragrance-free detergents, fragrance-free skincare products, non-preservative-based skincare products will mitigate the environmental triggers.

And then the third thing is just calming the immune system down. And that can be done in a variety of ways. Most commonly, it's topical medications like topical steroids that dampen the immune system and the skin. And when eczema is really, really bad, there are biologic medications that control certain interleukins, and they've made an incredible advancement in eczema control.

People, we can control patients for life with some of these injectable medicines. - A couple of things that you taught me that I just wanna pass along in short form, and please correct me if I have this wrong. One, if you can avoid popping pimples, definitely avoid it because it can cause damage, recruitment of these matrix metalloproteases, which essentially digest some of the deeper layers of the skin, leave scars.

- Yeah, yeah, totally. So it's, I mean, it's very gratifying, and you wanna do it. There's like some subconscious desire to like pop a pimple. I have it myself. Anytime I see a pimple, I'm like, "Man, I gotta, I wanna get at this thing." - I think it's to eradicate the infection type of thing.

You know, even if it's not an infection, I think that's the- - Possibly, like a evolutionary reason. - Yeah, very, very possible. The reason we don't wanna do that, and the reason why we always say don't pick at your skin is when there's an immune response in the skin, the immune system's trying to fix something and fight something, and in doing so, it recruits different enzymes.

The most common enzyme is what you exactly described, matrix metalloproteinases, which are these enzymes that eat apart collagen and elastin to allow it to remodel. When you cause physical trauma in the skin, you recruit a much larger immune response than what was warranted for that insult. So these MMPs, these matrix metalloproteinases, enter at a much higher amount, and they eat away at the collagen and elastin.

That's what leaves an acne scar. Now, people are gonna pop their pimples, whether we want to or not. So if you're gonna do it, I don't recommend it, but if you're gonna do it, generally what we recommend is if there is no tip, don't even think about it. If there is a small white tip and not much pain or induration, you can use a warm compress to see if you can soften that and see if it'll expel itself.

Pushing, we don't recommend. Stretching can sometimes unroof a pimple, tends to cause less trauma. But again, if you listen to one thing, don't do it. - And if they pop on their own, can't believe we're having this conversation, but it's a skin health and appearance episode after all, if they pop on their own, then cleaning it with a gentle cleanser is probably the best way to go.

No topical antibiotics, is that right? - Don't use any hydrogen peroxide. It's a common misconception thinking it fights things. Peroxide doesn't let wounds heal. It just kills anything living. So no peroxide and no topical antibiotics that are over the counter. Most of these don't have any antibiotic properties anyway, 'cause most organisms are resistant to them because of the widespread availability and use.

And two, they cause a lot of allergic contact, dermatitis and rashes in people who are susceptible to them. So we just say, if it pops on its own, leave it alone. They wanna put a little ointment on there if you have a sore, but otherwise ignore it. - And what about the use of corticosterone cream?

Like if somebody has a red bump and they're headed to an event or something and they wanna eliminate some of the redness and bumpiness. - So a common thing we see a lot of people for, it's like a day before their wedding or a day before a big social event and they have a zit on their forehead and they say, you know, what can you do for me?

I need this gone. So exactly like we talked about, topical corticosteroids and to a greater extent injectable, intralesional corticosteroids suppress the immune response temporarily. So you can use them cautiously if you have an event within the next day or two. Long-term use, it causes multiple problems. It causes thinning of the skin and can increase the risk of the acne scar forming.

And you can have rebound acne from topical steroids used all over the face. Oftentimes we see a lot of people who are in the public eye asking for steroid injections of their acne. I, as a surgeon, usually see a lot of the consequences of that, so I tend not to utilize steroid injections for acne.

The reason for that is if you place just a little too much, and we're talking less than 0.1 milliliter difference, you can have a permanent atrophic divot in the skin that is only fixed by surgery. So I see a lot of young patients that come in who had an acne spot injected here and now that divot is left and that's permanent.

If it's gonna be done, it should be done by a dermatologist who knows what they're doing. Low concentrations, usually bottom half of the face can be effective in getting rid of a really bad pimple that needs to be gone immediately. You just gotta know the risks. - Assuming sterile technique and other safety measures in place, are tattoos inherently bad for skin?

- No, I don't think so. I think tattoos are an awesome form of art and I think it used to be linked to, you know, stereotypes that are no longer true. I think the challenge with tattoos is two things, making sure that what is being placed underneath the skin is not an allergen.

We see this mostly with the reds that use cinnamates. They produce a lot of granulomatous reactions or foreign body reactions. One, making sure obviously they're using clean, safe equipment that's sterile. You know, you don't want the bloodborne pathogens. The real challenge is surveying for growths. In patients who have a lot of tattoos, it's hard to see small skin cancers form or changes in moles because usually the tattoos are of dark color.

So the surveillance part becomes a little bit more challenging. So if you have a lot of tattoos, just make sure to see your dermatologist and somebody who feels comfortable and confident in screening. But other than that, no. They've been around for hundreds and hundreds of years and I think they're fine if done correctly.

- That's a good segue into surveying for skin cancers. Earlier, you talked about some of the more common forms of skin cancer, squamous cell carcinoma, basal cell carcinoma. But then there's the one no one truly wants, which is melanoma. So I was taught to keep an eye on my moles.

If they change, change in border, change in size, et cetera, to notify a dermatologist. I get my moles checked about, I don't know, I just had it done less than a year ago. But what about getting all skin checked? I mean, what do you, this is your area of expertise.

So if you had a magic wand to help prevent skin cancers, what would you have people do? - That's a great, great question. So obviously there are many forms of skin cancer, but the three most common, like we talked about, basal cell carcinoma, squamous cell carcinoma, and melanoma. There are other types like Merkel cell and et cetera, but they're far less common.

Now, historically, melanoma has been our number one killer for skin cancer until about a few years ago, around 2018, when the Nobel Prize was won for the new drugs that treated melanoma. This year, we expect three times as many deaths in the United States from squamous cell carcinoma than we do melanoma, but nobody talks about that.

We lose a patient every about 62 minutes to melanoma, but one every 37 minutes to squamous cell carcinoma. First and foremost, the thing that you wanna look for in terms of skin cancer risk and predisposition is look at family history. Your family history and your genetics plays the largest role in predisposition for skin cancer development.

If you can gather a family history, you can understand your risk in developing it, and it can help dictate your screening. Now, if you can't get a family history or you don't know your family history, not a problem. Generally, we recommend an annual skin exam by a good, reputable, board-certified dermatologist, and that includes every square inch of your skin, including your hair between your toes in the genital area.

We can develop a skin cancer anywhere. Bob Marley died of a melanoma on his toenail that was thought to be a soccer injury. Jimmy Buffett died of a Merkel cell carcinoma, one of these rarer types that occur in sun-exposed areas. Anybody can get them. Obviously, there's predispositions in higher-risk populations, but it's such an easy, non-invasive exam to do that everybody should get one at least once a year.

The other reason why I bring this up is skin cancers can develop in sun-protected areas. One of the areas that I see a rapid increase in skin cancer development is in genital areas and in the mouth due to HPV, and we see this a lot in younger and younger patients.

Probably in the last month, I've operated on six or seven young patients under the age of 40 with squamous cell carcinomas caused by HPV in the genital region. This is obviously not sun-driven. It's not something you can put sunscreen or take a product to protect you from, but it's something that's easily monitored or surveyed.

So I would say at the very minimum, get a family history or a personal history, get an annual surveillance exam. If you have a lot of moles, I used to direct the pigmented lesions in melanoma clinic. This is something that was really hard for a lot of dermatologists and patients to follow when they're covered with moles, see which one is changing.

There are tools that can be utilized, including whole body photography, mole mapping, and some new AI-based softwares that basically track the moles and look for changes as you feed the software more and more pictures from the patients. It's fascinating. A lot of the stuff is developing from our, well, I should say my alma mater, but up at Stanford is these AI-based software apps that allow us to survey some of the most challenging patients.

So if you have a lot of moles, your screening may be more than once a year. If you have a lot of moles, you inherently have a slightly increased risk for melanoma. Now, we always use these terms interchangeably, melanoma, skin cancer, basal, squamous, et cetera. Importantly to know, for every one melanoma, there's 10 non-melanoma skin cancers.

That's namely basal cell and squamous cell. About 5 million Americans will be diagnosed with one of the non-melanomas this year alone. - 5 million. - 5 million. - It's a big number. - Yeah, it's about one in four. One in four Americans at some point in their lifetime will develop a skin cancer, encroaching one in three Americans by the end of 2030.

So it's a lot. Majority of these are not life-threatening, but they're functionally and cosmetically disfiguring. They arise on sun-exposed areas, so surveillance is really important. - For the HPV that eventually becomes squamous cell, carcinoma, is the HPV vaccine effective even at older ages? - Yeah, great question. So we are seeing HPV become a real problem in many cancers in the body, not just the original cervical cancer, which was the number one killer in young women for cancer until the vaccine came out, but we're seeing it now as the number one cause of throat cancer in young adults and sexually active adults, significantly increased risk of squamous cell carcinomas in sun-protected areas, immunosuppressed patients.

The vaccine, the Gardasil vaccine, which treats or builds immunity to HPV covers the strains that cause cancer, 16, 18, 31, 33, and so on. I recommend anybody who is either sexually active or anybody who, in population, literally anyone, should get vaccinated. The new guidelines have extended the age up until I think late 40s for both men and women.

It used to be only for young women because the cervical cancer risk, but now we've found that so many things are implicated with HPV that the on-label use is up to the late 40s. So if you have any concern, I highly recommend getting the vaccine. - As I recall, planter's warts, which are these warts that burrow a kind of root into the bottom of the foot.

They're very painful. That actually can be caused by HPV. It's a form of HPV, and it's not sexually transmitted. It's locker room transmitted. - Yeah, so HPV comes in about 200 strains or like 190 strains. Strains one, two, and four, for example, cause warts on the hands and feet.

What you see like gym goers and kids, they get warts. HPV six and 11, for example, cause genital warts. HPV strains 16, 18, 31, and 33 cause cancer. The question is when you get something, does it come with its brothers or its siblings? And that's the question we don't know.

The vaccine was made to treat high-risk strains, but because of cross-antigenicity, we see that patients who get vaccinated, their warts go away. And we saw this in the hospital in transplant patients who were covered with warts because of their immunosuppressed effect. When we would vaccinate them, their warts would get better.

- So warts on their fingers, warts on their, planter's warts on their feet. - Yeah, transplant patients and anybody who is immunosuppressed, they have a tough time fighting plantar's warts, finger warts, any sort of viral-based condition because their immune system is suppressed from medications or otherwise. So they usually have a tough time fighting these things.

They have a higher incidence of a lot of things, but the vaccine was cool, eradicating it. Now, I'm not saying go get a vaccine cause you have a plantar wart, that's silly and overkill. Usually warts we treat with freezing in office procedures, easy things, but. - Plantar's warts can be burnt out.

- Yeah, we burn them or freeze them or scrape them, use a little medication, but the vaccine does improve some of the burden of disease, even though it doesn't target that strain. - Do you think soon we will be in the landscape of vaccines for all forms of skin cancer?

- I think we're on the forefront. And the term vaccine is a really big umbrella term. - Loaded term too. - Yeah, I know, it's gonna garner a lot of questions. I think, yes, absolutely. There was a new study that showed that an mRNA vaccine, and that is already pretty controversial, was shown to improve melanoma survival after surgery and chemotherapy.

So what the goal of all these things is to prime your immune system and have the immune system know what to target. It's to teach the immune system, hey, this is bad, next time you see this, go attack it. It's like showing a bloodhound a steak and then going on the hunt.

The bloodhound now knows what to scent for and what is normal and what isn't. So the vaccines have a lot of controversial things. I think for medicine and cancer biology, it's gonna be revolutionary. We see it for brain tumors, we see it for glioblastoma, incredible changes with dendritic cell vaccines.

We see it for melanoma now. And in the future, it may be used for all skin cancers with an asterisk, depending on how much we can activate the immune system to target it. - Fascinating, and a good place for us to probably pause until the next time we have you back to talk about where that technology evolves.

Because today you've taught us so much about skin, what it is, its anatomy, its physiology, what it reflects in terms of our internal workings, health, or in some cases, challenges with health. Talked about various conditions such as psoriasis, acne, eczema, dandruff, as it's sometimes called, and what we can do, the role of nutrition, avoiding certain things like excess alcohol, nicotine, et cetera, but also some of the newer and more exciting treatments that exist for all these conditions, some merely cosmetic and uncomfortable, some truly life-threatening and dangerous like melanoma.

So for all those reasons, and also for taking time out of your very busy clinical schedule to come talk to us, I really appreciate it, and I want to voice my appreciation, both for myself and for those listening and viewing. I know people will have many, many questions, so we will refer them to your social media accounts and links to your clinic and so forth so that they can have those questions addressed and who knows, maybe even get the chance to work with you.

In the meantime, I just want to say thank you for this public education gift that you've given us. I'm thinking about skin very differently now, and I plan to do and not do certain things in light of today's conversation, no pun intended. - Thank you for the opportunity. I'm incredibly grateful to be here.

I think teaching is really important. Having evidence-based discussions is really important. Challenging dogma is also important, done in the right way, in the evidence-based way. I love what I do. I love everything about the skin. I love seeing patients and also challenging the status quo on certain things. So thank you for the opportunity.

It's been a lot of fun. There's a lot to talk about in skin. We can probably talk for a decade if you let me, but I appreciate it, thank you. - Well, we will certainly bring you back to further the discussion. Meanwhile, thank you ever so much, Dr. Soleimani.

- Thank you. - Thank you for joining me for today's discussion about how to improve and protect your skin with Dr. Teo Soleimani. To learn more about his work and find links to his clinic, please see the show note captions. If you're learning from and/or enjoying this podcast, please subscribe to our YouTube channel.

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