How to Optimize Testosterone & Estrogen

00:00:00.000 | - Welcome to Huberman Lab Essentials,

00:00:02.320 | where we revisit past episodes

00:00:04.380 | for the most potent and actionable science-based tools

00:00:07.560 | for mental health, physical health, and performance.

00:00:10.320 | I'm Andrew Huberman,

00:00:12.560 | and I'm a professor of neurobiology and ophthalmology

00:00:15.400 | at Stanford School of Medicine.

00:00:17.440 | This podcast is separate

00:00:18.680 | from my teaching and research roles at Stanford.

00:00:21.080 | Before we begin today,

00:00:22.440 | just want to acknowledge that

00:00:23.640 | if you're watching this on YouTube,

00:00:25.000 | yes, I have a bandage on the left side of my face.

00:00:28.000 | I was trying to cook something for Costello and I,

00:00:30.360 | and I got burned, burned myself.

00:00:32.400 | It was a cooking accident.

00:00:33.460 | I'm fine.

00:00:34.300 | No need to dwell on it.

00:00:35.160 | We can move on.

00:00:36.040 | But I just wanted to let you know,

00:00:37.160 | everybody's going to be okay.

00:00:38.200 | He got a great meal.

00:00:39.280 | I got a burn and a great meal.

00:00:41.060 | Today, we're going to be talking about hormone optimization,

00:00:43.920 | and we're mainly going to be focusing

00:00:45.720 | on estrogen and testosterone and their derivatives.

00:00:48.640 | Now, estrogen and testosterone and their derivatives

00:00:51.360 | are what we call sex steroids.

00:00:53.720 | But I just want to emphasize that estrogen and testosterone

00:00:56.760 | are present in everybody.

00:00:58.500 | It's their ratios that determine their effects.

00:01:01.440 | So today, we're going to talk about

00:01:02.740 | how specific types of exercise,

00:01:04.960 | particular patterns of cold exposure,

00:01:07.200 | as well as particular patterns, believe it or not,

00:01:09.260 | of breathing can impact sex steroid hormones,

00:01:13.080 | both estrogen and testosterone.

00:01:15.080 | So one of the first things to understand

00:01:17.020 | if you want to optimize your hormones

00:01:19.200 | is where they come from.

00:01:20.980 | There are a lot of different glands in the body

00:01:22.720 | that produce hormones.

00:01:23.920 | But when we're talking about the sex steroid hormones,

00:01:25.920 | estrogen and testosterone,

00:01:27.240 | the major sources are ovaries for estrogen

00:01:30.480 | and the testes for testosterone,

00:01:32.100 | although the adrenals can also make testosterone.

00:01:35.880 | Now, there are also some enzymes.

00:01:38.160 | Enzymes are things that can change chemical composition.

00:01:42.520 | And the enzymes that we're going to talk about today

00:01:44.600 | are the aromatases mainly.

00:01:46.680 | The aromatases convert testosterone into estrogen.

00:01:50.240 | So in a male, for instance, that has very high testosterone,

00:01:54.120 | some of that is going to be converted

00:01:55.880 | into estrogen by aromatase.

00:01:57.800 | The important thing to know is that prepubescent females

00:02:00.640 | make very little estrogen.

00:02:02.400 | And when we talk about estrogen,

00:02:03.400 | we mainly talk about estradiol,

00:02:05.080 | which is the most active form of estrogen

00:02:07.280 | in both males and females.

00:02:09.060 | So prepubescent females, very low levels of estrogen.

00:02:12.600 | During puberty, levels of estrogen, aka estradiol,

00:02:16.960 | basically skyrocket.

00:02:18.480 | And then across the lifespan,

00:02:20.960 | estrogen is going to vary

00:02:22.120 | depending on the stage of the menstrual cycle,

00:02:24.060 | but as one heads into menopause,

00:02:25.920 | which typically takes place nowadays

00:02:27.800 | somewhere between age 45 and 60,

00:02:30.560 | levels of estrogen are going to drop.

00:02:32.060 | And then post-menopause levels of estrogen are very low.

00:02:34.860 | As well, testosterone will fluctuate across the lifespan.

00:02:38.600 | Testosterone is going to be relatively low

00:02:40.960 | pre-puberty in males.

00:02:43.080 | During puberty, it's going to skyrocket.

00:02:45.600 | And then the current numbers are that it drops off

00:02:48.920 | at about a rate of 1% per year.

00:02:51.600 | So let's talk about other sources of these hormones,

00:02:54.980 | and then it will make clear what avenues

00:02:58.300 | you might want to take in order to optimize these hormones.

00:03:01.600 | The other glands and tissues in the body

00:03:03.740 | that make these hormones, testosterone and estrogen,

00:03:06.680 | as I mentioned briefly, are the adrenals.

00:03:08.900 | So the adrenals ride up top the kidneys,

00:03:11.180 | and the release of these steroid hormones from the adrenals,

00:03:15.260 | in particular testosterone

00:03:16.540 | and some of its related derivatives,

00:03:19.340 | are mainly activated by competition.

00:03:23.120 | Pretty interesting.

00:03:24.280 | There's a lot of evidence in animals and humans

00:03:27.760 | that competitive scenarios,

00:03:29.400 | at least short-lived competitive scenarios,

00:03:31.480 | can liberate testosterone from the adrenals.

00:03:33.920 | So let's talk about competition,

00:03:35.960 | because it turns out that competition

00:03:38.560 | is a powerful influence on the sex steroid hormones,

00:03:43.040 | and the sex steroid hormones powerfully influence

00:03:45.760 | competition.

00:03:47.240 | So most people don't realize this,

00:03:48.680 | but most males of a given mammalian species

00:03:52.620 | never get to reproduce.

00:03:53.920 | In fact, they never even get to have sex at all.

00:03:56.960 | And we don't often think about that,

00:03:58.640 | but testosterone plays a powerful role

00:04:01.980 | in determining which members of a given species

00:04:04.400 | will get to reproduce,

00:04:05.720 | which ones of that species

00:04:07.880 | will actually get access to females.

00:04:10.520 | And so here I'm not talking about humans specifically,

00:04:13.680 | but it's well-known in species like elephant seals,

00:04:18.240 | in species like antlered animals and rams, for instance,

00:04:23.040 | that the higher levels of testosterone

00:04:24.880 | correlate with access to females.

00:04:27.340 | Now, one interpretation of this

00:04:29.520 | is that the females are detecting

00:04:31.780 | which males have high testosterone and selecting them.

00:04:34.400 | They're more receptive to them.

00:04:35.600 | But it's actually more so

00:04:38.580 | that the males that have higher testosterone

00:04:41.120 | forage further and will fight harder for the females.

00:04:45.880 | And this is really interesting

00:04:47.160 | because there's very good evidence now

00:04:49.080 | that testosterone can reduce anxiety,

00:04:52.640 | promote novelty seeking,

00:04:54.560 | and promote competitive interactions.

00:04:57.960 | And so before you leap too far with this in your mind

00:05:00.380 | and think about all these human behaviors,

00:05:02.200 | just stay with me,

00:05:03.040 | 'cause there's a little bit of biology here

00:05:04.280 | that makes it all make sense.

00:05:05.600 | And it turns out to be pretty simple.

00:05:07.820 | We have a brain region called the amygdala.

00:05:11.840 | In Latin, that just means almond,

00:05:13.280 | but the amygdala is most famous for its role in fear.

00:05:15.840 | We hear a lot about fear and the amygdala,

00:05:18.400 | but the amygdala is really involved in threat detection.

00:05:21.440 | It sets our thresholds for anxiety

00:05:24.160 | and what we consider scary or too much.

00:05:27.660 | Testosterone secreted from the gonads

00:05:30.280 | and elsewhere in the body

00:05:31.600 | binds to the amygdala

00:05:33.560 | and changes the threshold for stress.

00:05:36.400 | So I've said before on previous versions of this podcast

00:05:39.860 | and on other podcasts,

00:05:41.220 | that testosterone has this incredible effect

00:05:43.920 | of making effort feel good.

00:05:46.640 | But what I was really referring to

00:05:48.040 | is the fact that testosterone lowers stress and anxiety

00:05:51.280 | in particular in males of a given species.

00:05:54.800 | Testosterone increases generally lead to more foraging,

00:05:59.440 | more novelty seeking,

00:06:01.160 | increases in libido and increases in desire to mate.

00:06:04.840 | So it is the case that increases in testosterone

00:06:07.520 | promote competitive and foraging type behaviors

00:06:10.640 | in humans and in non-human mammals.

00:06:14.800 | But it's also true that competition itself

00:06:18.840 | can increase androgens such as testosterone.

00:06:21.800 | Now, some people have come to the conclusion

00:06:24.700 | that if you win, your testosterone goes up

00:06:27.040 | and if you lose, your testosterone goes down.

00:06:30.020 | And to some extent that's true,

00:06:31.600 | but that's not a direct effect on the gonads.

00:06:33.680 | That's actually mediated by the neuromodulator dopamine.

00:06:36.460 | We talked about dopamine in the episode

00:06:38.160 | on motivation and drive.

00:06:40.000 | And dopamine and testosterone

00:06:41.400 | have a remarkable interplay in the body.

00:06:44.300 | Dopamine is actually released in the brain

00:06:46.400 | in ways that has the pituitary,

00:06:48.600 | this gland that sits over the roof of your mouth,

00:06:50.880 | release certain hormones that then go on

00:06:52.880 | to promote the release of more testosterone.

00:06:55.360 | And indeed winning promotes more dopamine

00:06:59.120 | and later more testosterone.

00:07:01.840 | However, in the short term,

00:07:03.740 | just competing increases testosterone

00:07:06.320 | independent of whether or not you win or lose.

00:07:09.300 | So testosterone is driving the seeking of sex

00:07:12.040 | and estrogen is promoting the actual act of sex

00:07:16.720 | from female so-called receptivity, consensual receptivity.

00:07:20.360 | In males, it's interesting to point out

00:07:22.360 | that testosterone is promoting seeking of sex,

00:07:25.600 | but it's also estrogen in males

00:07:28.880 | that's important for libido.

00:07:30.280 | If estrogen levels are brought too low,

00:07:32.920 | then men will completely lose their libido.

00:07:35.280 | So it's not simply the case that high levels of testosterone

00:07:38.600 | produce a lot of sex and mating behavior

00:07:41.620 | and low levels of estrogen are good across the board.

00:07:43.900 | You actually need both in both males and females.

00:07:46.740 | It's just that in females,

00:07:48.260 | the testosterone levels are always going to be lower

00:07:50.980 | than the estrogen levels.

00:07:52.020 | And in males, the estrogen levels

00:07:53.800 | are always going to be lower than testosterone levels.

00:07:56.060 | So just as there are behaviors

00:07:57.320 | that can increase testosterone,

00:07:59.440 | there are behaviors that can decrease testosterone.

00:08:02.700 | And one of the most well-characterized ones in humans

00:08:06.460 | is becoming a parent.

00:08:09.200 | So expecting fathers have an almost 50% decrease

00:08:14.200 | in testosterone levels,

00:08:16.080 | both free and bound testosterone.

00:08:18.860 | It turns out that these effects of reduced testosterone,

00:08:22.080 | increased estradiol and reduced cortisol

00:08:24.440 | can all be explained by an increase in prolactin.

00:08:28.060 | It is a well-known phenomenon

00:08:29.880 | that testosterone is going to drop,

00:08:31.520 | prolactin is going to increase,

00:08:33.080 | estradiol is going to increase in males and females

00:08:36.600 | that are expecting children.

00:08:38.300 | The other behavior that markedly reduces testosterone

00:08:41.940 | in both males and females

00:08:43.480 | and markedly reduces the desire for seeking sex

00:08:46.780 | and sex itself is illness.

00:08:49.740 | And many of you might say, well, duh,

00:08:52.020 | when people don't feel sick,

00:08:53.120 | they don't feel like seeking out mates

00:08:54.660 | and they don't feel like having sex.

00:08:56.140 | But have you ever wondered why that actually is?

00:08:58.660 | Well, it turns out that it can be explained

00:09:01.100 | by the release of what are called inflammatory cytokines.

00:09:04.280 | So cytokines are related to the immune system.

00:09:06.800 | They travel in the lymph and in the blood

00:09:08.680 | and they attack invader cells like bacteria and viruses.

00:09:12.460 | And under conditions of illness,

00:09:14.440 | we make a lot of different cytokines.

00:09:16.200 | Some of them are anti-inflammatory,

00:09:18.180 | but some of them are pro-inflammatory.

00:09:20.280 | And the best known example of a pro-inflammatory cytokine

00:09:23.400 | is IL-6.

00:09:25.480 | And it's known that IL-6 when injected into individuals

00:09:29.740 | will decrease the desire for sex

00:09:32.240 | and eventually will reduce levels of testosterone

00:09:34.880 | and estrogen independent of feeling lousy.

00:09:38.120 | Now, IL-6 doesn't just travel to the gonads

00:09:40.480 | and shut down the gonads.

00:09:41.520 | It actually has ways to interact with some of the receptors

00:09:45.160 | that the steroid hormones, estrogen and testosterone,

00:09:47.560 | bind to and impact those receptors

00:09:49.880 | so that the sex steroid hormones can't have their effect.

00:09:52.620 | In short and put simply,

00:09:54.680 | inflammatory cytokines like IL-6

00:09:56.920 | are bad for sex steroid hormones.

00:09:58.920 | One of the main behaviors

00:10:00.720 | that's been shown to be associated

00:10:02.940 | with poor levels of estrogen

00:10:06.760 | relative to age match controls for people with ovaries

00:10:10.080 | or lower levels of testosterone

00:10:12.800 | compared to age match controls for people with testes

00:10:16.160 | is apnea.

00:10:19.380 | So what is apnea?

00:10:20.880 | Apnea is under breathing

00:10:22.580 | or mainly cessation of breathing during sleep.

00:10:26.120 | So people are holding their breath

00:10:27.360 | and then they'll suddenly wake up.

00:10:29.200 | People who are dramatically overweight

00:10:32.420 | also suffer a lot from apnea during sleep.

00:10:35.120 | And it's well-established that going into deep sleep

00:10:40.000 | and getting the proper patterns of slow wave sleep

00:10:42.080 | and REM sleep are important for hormone optimization.

00:10:45.080 | Breathing itself can be adjusted in the daytime waking hours

00:10:49.700 | in ways that can powerfully impact both sleep,

00:10:52.520 | reduce incidence of sleep apnea,

00:10:54.740 | and also help to optimize various hormones

00:10:58.280 | even just by breathing in particular ways while awake.

00:11:01.240 | Believe it or not,

00:11:02.320 | being a nasal breather and avoiding being a mouth breather

00:11:05.480 | can actually positively impact hormones.

00:11:08.400 | And in particular, the hormones, testosterone and estrogen.

00:11:11.440 | Although the way that it does that

00:11:13.680 | is by making you a better sleeper,

00:11:16.240 | which allows you to produce more testosterone

00:11:18.920 | and the appropriate amounts of testosterone and estrogen.

00:11:23.060 | But it does that in part through indirect mechanisms

00:11:27.160 | because deep sleep supports the gonads,

00:11:29.120 | the ovaries and the testicles

00:11:30.840 | and their turnover of cells and the production of cells.

00:11:33.560 | Remember in the ovary particular cells

00:11:36.320 | and the egg follicles themselves make estrogen

00:11:38.720 | and in the testicle that the Sertoli cells

00:11:43.720 | and the Leydig cells are important

00:11:45.760 | for the formation of sperm

00:11:47.320 | and for testosterone respectively.

00:11:49.320 | So what does this all mean?

00:11:51.600 | This means we have to be breathing properly

00:11:54.100 | to get your breathing and sleep right

00:11:55.700 | so that your sleep can actually be deep enough

00:11:57.720 | and you're not entering apnea states.

00:11:59.980 | Getting proper sleep can really offset all the reductions

00:12:03.260 | in testosterone and estrogen

00:12:04.640 | and reductions in fertility that occur

00:12:06.480 | if we don't get enough sleep.

00:12:07.780 | But seldom is it discussed

00:12:09.460 | how sleep actually adjusts things

00:12:11.940 | like testosterone and estrogen.

00:12:13.460 | And it does it by modifying cortisol.

00:12:16.740 | So the molecule cholesterol

00:12:18.820 | can be converted into testosterone or estrogen

00:12:22.700 | but there's a competition

00:12:24.760 | whereby the cholesterol will turn into cortisol

00:12:28.260 | and not testosterone

00:12:29.700 | or it'll turn into cortisol and not estrogen

00:12:33.460 | if stress levels are too high.

00:12:35.420 | So the simple version of this

00:12:36.960 | is getting your breathing right during the waking hours

00:12:40.420 | meaning primarily unless you're working out really hard

00:12:43.620 | or there's some other reason

00:12:44.520 | why you're maybe eating or speaking

00:12:46.660 | that you need to be breathing through your mouth,

00:12:47.860 | you should be a nose breather.

00:12:49.380 | There's really good evidence for that now.

00:12:51.840 | And in sleep, you also want to be a nose breather

00:12:54.740 | because that's going to increase the amount of oxygen

00:12:57.380 | that you're bringing into your system

00:12:58.380 | and the amount of carbon dioxide that you're offloading.

00:13:01.100 | So the simple version of this is get your breathing right.

00:13:03.740 | So how do you do that?

00:13:04.580 | How do you get your breathing right?

00:13:05.540 | Well, for some people that have severe sleep apnea,

00:13:08.540 | they're going to need the CPAP machine.

00:13:10.300 | This is a machine that you actually put on your face

00:13:12.020 | and it helps you breathe properly and sleep.

00:13:14.260 | In the daytime, the best way to get good at nasal breathing

00:13:18.120 | is to dilate the nasal passages

00:13:19.840 | 'cause a lot of people have a hard time

00:13:21.180 | breathing through their nose.

00:13:22.940 | And one way to do this

00:13:24.240 | is to just breathe through your nose more.

00:13:26.020 | And one way to do that is that when you exercise

00:13:28.340 | in particular cardiovascular exercise,

00:13:30.500 | most of the time, provided you're not in maximum effort,

00:13:33.240 | you should be nasal breathing.

00:13:34.940 | Now, for a lot of people,

00:13:36.520 | nasal breathing during exercise is hard at first,

00:13:39.100 | but as you do it because the sinuses

00:13:41.500 | have a capacity to dilate over time,

00:13:44.020 | you'll get better at it.

00:13:45.300 | So my advice would be breathe through your nose

00:13:49.820 | while exercising unless you're in maximum effort.

00:13:52.960 | Pretty soon what you'll find

00:13:54.060 | is you actually can create more output

00:13:56.720 | than you would if you were breathing through your mouth.

00:13:58.640 | Learn to be a nasal breather.

00:14:00.060 | Has positive cosmetic effects.

00:14:01.820 | It reduces apnea.

00:14:03.340 | It offloads more carbon dioxide.

00:14:05.020 | It increases lung capacity.

00:14:06.620 | It dilates the sinuses and it prevents apnea in sleep.

00:14:11.040 | So unless you have severe apnea and you need the CPAP,

00:14:13.820 | becoming a nasal breather

00:14:15.540 | can have all sorts of positive effects

00:14:17.020 | by reducing cortisol, reducing apnea,

00:14:19.860 | and indirectly raising testosterone and estrogen

00:14:23.780 | in the proper ratios.

00:14:25.500 | The second piece of behavioral advice

00:14:27.260 | relates to the viewing of light.

00:14:30.360 | And many of you have heard me talk about this before,

00:14:32.980 | and I'm not going to belabor the point

00:14:34.860 | that viewing bright light within the first hour of waking,

00:14:38.160 | whether or not it's from artificial light

00:14:39.500 | or ideally from sunlight,

00:14:40.780 | has these powerful effects on sleep and wakefulness.

00:14:43.880 | But we have to return to this if you want to understand

00:14:46.780 | how light can impact hormones,

00:14:48.840 | because hormones, light, and dopamine

00:14:52.020 | have a very close-knit relationship,

00:14:53.860 | so much so that your light-viewing behavior

00:14:57.220 | can actually have a direct effect

00:14:59.340 | on hormone levels and fertility.

00:15:01.460 | I think most people don't really understand

00:15:03.700 | how powerful this relationship is

00:15:05.200 | between light, dopamine, hormones.

00:15:07.900 | And when dopamine levels are high, as I mentioned before,

00:15:10.260 | there's a tendency for more

00:15:12.100 | gonadotropin-releasing hormone,

00:15:13.540 | luteinizing hormone, follicle-stimulating hormone,

00:15:15.580 | all the hormones that come

00:15:16.540 | from the hypothalamic-pituitary axis

00:15:18.900 | and stimulate estrogen and testosterone release

00:15:21.660 | from the ovary and testes.

00:15:24.540 | So how does this translate to a protocol?

00:15:27.140 | If you want to optimize testosterone and estrogen,

00:15:30.500 | you need to get your light-viewing behavior correct.

00:15:33.140 | It's not just about optimizing your sleep,

00:15:36.060 | which is also important,

00:15:37.140 | it's about getting a sufficient amount of light in your eyes

00:15:39.860 | so you have sufficient levels of dopamine.

00:15:42.220 | So the simple protocols for that I've reviewed before,

00:15:45.220 | but it means getting anywhere from two to 10 minutes

00:15:47.340 | of bright light exposure in your eyes early in the day.

00:15:50.100 | It is not sufficient to do this with sunglasses

00:15:52.820 | unless you have to do that for safety reasons.

00:15:54.620 | It's fine to wear prescription lenses and contacts.

00:15:57.260 | If you can't get sunlight for whatever reason,

00:15:59.220 | you want to use bright artificial light.

00:16:01.020 | But that is absolutely critical

00:16:03.020 | for timing the cortisol release properly,

00:16:05.420 | limiting cortisol release to the early part of the day,

00:16:07.980 | getting increases in dopamine that are going to promote

00:16:10.760 | the production of testosterone and estrogen

00:16:12.980 | to healthy levels.

00:16:14.220 | The other aspect of light-viewing behavior

00:16:15.940 | that's extremely important

00:16:17.460 | is to avoid bright light exposure to your eyes

00:16:21.620 | in the middle of the night.

00:16:22.740 | If you're viewing bright light in the middle of the night,

00:16:24.580 | you are suppressing dopamine release.

00:16:26.560 | If you're suppressing dopamine release,

00:16:28.300 | you are suppressing testosterone levels.

00:16:30.980 | So you can't even begin to talk about supplements

00:16:33.380 | and other ways to optimize testosterone,

00:16:35.260 | diet and its effects on testosterone and estrogen

00:16:37.420 | and fertility and reproductive behavior, et cetera,

00:16:40.240 | until you get your breathing right,

00:16:42.100 | until you get things like

00:16:43.900 | your light-viewing behavior right.

00:16:45.620 | So bright light early in the day

00:16:47.160 | and throughout the day is great.

00:16:49.060 | And avoiding bright light in the middle of the night

00:16:50.740 | is not just about not disrupting your sleep.

00:16:53.540 | It's also about optimizing the sex steroid hormones.

00:16:56.540 | Okay, so we've talked about breathing.

00:16:58.100 | We've talked about light.

00:16:59.640 | Let's talk about a third element

00:17:02.000 | that there seems to be some excitement about lately.

00:17:05.340 | For other reasons, but that can actually have

00:17:07.660 | some pretty profound influences on hormone levels.

00:17:11.860 | And that's heat and cold.

00:17:13.900 | So as always, rather than just offer a tool,

00:17:16.540 | I'm going to tell you the underlying science

00:17:18.780 | as it relates to naturally occurring phenomenon,

00:17:21.080 | because in understanding that

00:17:22.420 | and understanding the mechanism,

00:17:23.880 | you're going to be in a far better position

00:17:26.220 | to understand the tools and mechanisms

00:17:28.420 | and how you might want to adjust them for your own life.

00:17:31.460 | So now you understand the relationship

00:17:33.860 | between light, day length, dopamine, and hormone levels.

00:17:37.860 | And everyone should realize that temperature

00:17:40.420 | and day length are linked.

00:17:42.260 | Temperature and day length and sunlight,

00:17:45.660 | those are all intimately related

00:17:47.540 | because of the systems that we evolved in, right?

00:17:50.140 | So nowadays there's a lot of interest in using cold

00:17:53.900 | as a way to stimulate testosterone.

00:17:56.140 | Sounds pretty crazy, but believe it or not,

00:17:59.580 | that and things like ice baths and cold showers

00:18:02.300 | can have positive effects on the sex steroid hormones.

00:18:06.580 | What happens is there's a rebound

00:18:08.820 | in vasodilation after cooling.

00:18:10.660 | So cooling causes vasoconstriction.

00:18:13.900 | And then after the cooling, there's a rebound vasodilation

00:18:17.980 | and there's more infusion of blood into the gonads.

00:18:21.540 | Put simply, we don't know whether or not cold and heat

00:18:24.200 | directly affect the production of testosterone and estrogen.

00:18:28.940 | We only know that cold and heat can modulate those

00:18:32.580 | probably through indirect mechanisms

00:18:34.340 | like controlling the amount of blood flow

00:18:36.260 | by way of shutting down or activating the neurons.

00:18:39.540 | Now let's talk about particular forms of exercise

00:18:42.780 | and how they modulate the steroid hormones.

00:18:45.660 | So what's interesting is when you start digging

00:18:48.480 | into the more mechanistic studies,

00:18:50.880 | what you find is that heavy weight trainings,

00:18:54.280 | but not weight training to failure

00:18:56.500 | where completion of a repetition is impossible

00:18:59.780 | leads to the greatest increases in testosterone.

00:19:02.700 | So anywhere from one rep maximum

00:19:04.420 | to somewhere in the six to eight repetition range

00:19:08.180 | in males or females increases testosterone significantly.

00:19:12.140 | And it does it for about a day, sometimes up to 48 hours.

00:19:16.400 | Now, many of you might be endurance athletes

00:19:18.720 | or also enjoy exercise

00:19:21.220 | besides heavy weight-bearing exercise.

00:19:23.580 | And there are several studies exploring

00:19:25.980 | whether or not endurance activity

00:19:29.180 | can increase or decrease androgen levels

00:19:32.380 | and whether or not you combine endurance activity

00:19:35.060 | and weight training,

00:19:35.880 | whether or not that has any effect

00:19:37.380 | if you do the endurance activity first or second.

00:19:40.460 | And the takeaway from all of this

00:19:42.740 | was that endurance activity, if performed first,

00:19:46.600 | leads to decreases in testosterone

00:19:49.360 | during the weight training session

00:19:51.240 | as compared to the same weight training session done first

00:19:53.900 | followed by endurance activity.

00:19:55.220 | In other words, if you want to optimize testosterone levels,

00:19:58.140 | it seems to be the case that weight training first

00:20:00.620 | and doing cardio-type endurance activity afterward

00:20:04.100 | is the right order of business.

00:20:06.040 | Now, when these are done on separate days,

00:20:07.680 | it doesn't seem to have an effect.

00:20:09.500 | They showed no statistical interaction,

00:20:11.820 | but it seems that if you're going to do these

00:20:13.720 | in the same workout episode,

00:20:15.900 | that it's move heavy loads first,

00:20:18.140 | then do cardiovascular exercise.

00:20:20.580 | So there's a little bit of data looking specifically

00:20:23.100 | at how endurance exercise impacts testosterone

00:20:26.260 | and its derivatives.

00:20:27.260 | And it's very clear that high-intensity interval training,

00:20:29.860 | sprinting, et cetera,

00:20:31.060 | which somewhat mimics the neural activity

00:20:33.860 | that occurs while moving heavy weight loads

00:20:36.760 | is going to increase testosterone.

00:20:38.820 | There's ample evidence for that in the literature.

00:20:41.500 | And that endurance exercise that extends beyond 75 minutes

00:20:46.260 | is going to start to lead to reductions in testosterone,

00:20:48.700 | presumably by increases in cortisol.

00:20:51.020 | So now let's switch over to talking about estrogen.

00:20:54.900 | So there are many people

00:20:55.940 | who are trying to optimize their estrogen levels.

00:20:58.620 | And one of the places where this shows up a lot,

00:21:00.620 | and I get a lot of questions about, is menopause.

00:21:03.420 | So menopause, as I mentioned earlier,

00:21:05.280 | is this fairly massive reduction in the amount of estrogen

00:21:09.700 | that is circulating in one's blood,

00:21:11.740 | mainly because the ovary is now depleted

00:21:15.740 | of some estrogen production of its own,

00:21:17.860 | the eggs are not being produced,

00:21:19.560 | they've been depleted, et cetera.

00:21:21.820 | So menopause is characterized by a variety of symptoms.

00:21:24.900 | Things like hot flashes, things like mood swings,

00:21:28.040 | things like headaches, in particular migraine headaches.

00:21:31.340 | There can be a lot of brain fog.

00:21:33.040 | It can be very, very disruptive for people.

00:21:35.380 | So what are the various things

00:21:37.340 | that one can do for menopause?

00:21:38.920 | Well, one of the most common ones

00:21:41.540 | is that physicians will prescribe supplemental estrogen.

00:21:44.940 | So this is hormone therapy

00:21:46.700 | where somebody takes either oral estrogen

00:21:48.780 | or they'll use a patch or a pellet,

00:21:50.980 | some way to secrete estradiol into the system.

00:21:54.380 | And that has varying success, depending on the individual.

00:21:58.260 | Some people respond very well to it.

00:21:59.940 | Other people really have challenges with it.

00:22:02.180 | And there are a lot of side effects associated with it

00:22:04.260 | for some people, not others.

00:22:06.540 | In addition, there's a concern always

00:22:09.140 | about supplementing estrogen

00:22:10.780 | when there's a breast cancer background in the family,

00:22:15.060 | or there's concern about breast cancer for any reason,

00:22:17.140 | because a lot of those cancers are estrogen dependent.

00:22:20.060 | And that's why drugs like tamoxifen and anastrozole

00:22:24.100 | and drugs that block either aromatase

00:22:26.980 | or block, excuse me, estrogen receptors directly

00:22:30.180 | were initially developed.

00:22:31.300 | Okay, so now let's talk about the role of specific compounds,

00:22:34.340 | some of which, many of which,

00:22:35.840 | can be taken in supplementation form

00:22:37.900 | to optimize sex steroid hormones.

00:22:40.460 | It's very clear that certain collections of nutrients

00:22:45.340 | are useful for promoting testosterone and estrogen production

00:22:49.900 | in their proper ratios.

00:22:51.820 | And those things are what I would call

00:22:54.140 | the sort of usual suspects.

00:22:56.020 | Vitamin D, which is important

00:22:57.860 | for so many biological functions,

00:23:00.020 | including endocrine functions,

00:23:01.740 | zinc, magnesium, et cetera.

00:23:05.140 | One of the things that's been shown time and time again

00:23:07.560 | to have very negative effects on sex steroid hormones,

00:23:10.780 | testosterone mainly in men, estrogen mainly in women,

00:23:14.220 | is opioids.

00:23:16.140 | The opioids dramatically reduce levels

00:23:19.460 | of testosterone and estrogen.

00:23:21.420 | And they do that mainly by disrupting the receptors

00:23:25.460 | on gonadotropin-releasing hormone neurons,

00:23:27.740 | these neurons within the hypothalamus

00:23:29.300 | that communicate to the pituitary.

00:23:30.900 | And in fact, people that take large amounts of opioids

00:23:34.220 | or even take low levels of opioids for long periods of time

00:23:37.400 | will develop all sorts of endocrine syndromes.

00:23:39.980 | That's been shown over and over again.

00:23:41.820 | Gynecomastia or male breast development in males,

00:23:44.660 | disruptions to the ovary in females.

00:23:47.060 | It's really a quite terrible situation.

00:23:49.620 | So excessive opioids are very problematic

00:23:54.100 | for sex steroid hormones.

00:23:55.500 | Now there's an entire industry devoted to supplements

00:23:59.020 | and various things that people can take

00:24:00.420 | to increase testosterone.

00:24:01.780 | Some of which have scientific data to support them,

00:24:05.140 | some of which do not,

00:24:06.700 | and some of which have anecdotal support,

00:24:09.140 | and some of which do not.

00:24:10.820 | There are supplements, in particular Tonga Ali,

00:24:14.120 | which has this other name.

00:24:15.700 | It's something I call Tonga Ali.

00:24:17.640 | Sometimes it's called,

00:24:18.580 | and these, forgive me that it's hard to pronounce,

00:24:20.780 | but uricoma longifolia jack.

00:24:25.700 | This has been shown in several studies,

00:24:27.560 | and you can find these on examine.com

00:24:29.100 | or you can go to PubMed if you like.

00:24:30.380 | I've looked at these.

00:24:31.220 | That it does seem to have some pro-fertility,

00:24:33.740 | pro-free testosterone and subtle aphrodisiac effects.

00:24:39.140 | It does also seem to be a slight anti-estrogen.

00:24:42.520 | So the reports of this,

00:24:45.260 | people take this anywhere from 400 to 800 milligrams a day.

00:24:48.380 | Again, I'm not suggesting you do that,

00:24:49.840 | but that's kind of what's out there.

00:24:51.220 | And there is some decent scientific literature

00:24:53.820 | to support the fact that it liberates

00:24:55.660 | some of the bound testosterone

00:24:57.760 | and allows more free testosterone to be available.

00:25:00.500 | Some of the reported quote-unquote side effects

00:25:02.840 | are things like excessive alertness and insomnia

00:25:05.820 | if it's taken too late in the day and so forth.

00:25:07.620 | But I encourage you to explore that further

00:25:09.780 | if increasing free testosterone

00:25:11.500 | is something that you're interested in doing.

00:25:14.060 | People with different backgrounds and conditions

00:25:15.780 | as we talked about for menopause and estrogen

00:25:18.300 | have to be careful

00:25:19.300 | because when you're starting to modulate hormones,

00:25:22.100 | you're starting to modulate not just the tissues

00:25:25.220 | that thrive on binding of those hormones,

00:25:28.100 | but remember, the reason why there's so much breast cancer

00:25:32.420 | and there's a reason why there's so much testicular cancer

00:25:34.540 | is that any tissue that undergoes rapid reproduction

00:25:38.440 | of particular cells.

00:25:39.440 | So there's a lot of reproduction of cells

00:25:41.860 | and shedding of uterine lining

00:25:43.080 | and the reproduction of cells and eggs in the ovary.

00:25:45.760 | And in the testes, there's the production

00:25:47.460 | of Lydig and Sertoli cells.

00:25:50.420 | And there's this kind of ongoing production of sperm.

00:25:53.860 | That's why those tissues are particularly vulnerable

00:25:56.640 | to the development of cancers.

00:25:57.840 | And many of those cancers are androgen sensitive.

00:26:00.060 | That's why one of the major treatments

00:26:02.440 | for prostate overgrowth or prostate cancer

00:26:04.920 | is to give anti-androgenic drugs.

00:26:07.640 | It's really about trying to prevent testosterone

00:26:10.360 | from encouraging growth of tumors.

00:26:12.280 | So I want to really emphasize the caution there

00:26:16.160 | because it is easy when thinking about optimizing estrogen

00:26:19.520 | and testosterone to just think, oh, more is better.

00:26:22.080 | More is definitely not better.

00:26:23.560 | Any tissue that recycles itself is prone to cancers

00:26:28.400 | and those tissues thrive on androgens and estrogens

00:26:32.420 | to create more tumors.

00:26:33.800 | So you have to be careful

00:26:35.040 | anytime you're modulating hormones,

00:26:36.560 | especially androgens and estrogens.

00:26:39.280 | And while we're talking about supplementation,

00:26:41.420 | the effects of supplementation,

00:26:43.020 | I would say in some individuals can be quite dramatic,

00:26:46.720 | but they're always, always, always,

00:26:49.300 | except in extreme cases,

00:26:51.840 | going to be far more subtle than would be,

00:26:54.160 | for instance, just in injecting testosterone

00:26:57.120 | or injecting estrogen, et cetera.

00:26:59.360 | So I think we should just be honest and upfront about that.

00:27:02.700 | So thus far in terms of talking about optimizing hormones

00:27:06.420 | and in the discussion of supplementation,

00:27:08.860 | I haven't really talked about things

00:27:11.220 | that actually affect the brain directly,

00:27:13.160 | that increase the pituitary output and things of that sort.

00:27:16.220 | We've mainly been talking about things

00:27:17.300 | that free up testosterone

00:27:18.900 | or that increase estrogen at the level of the periphery.

00:27:22.020 | But if you remember way back

00:27:23.120 | to the beginning of this episode,

00:27:24.420 | hormones are made in different locations in the body

00:27:26.540 | and there are hormones that promote the release

00:27:29.260 | and the production of hormones

00:27:30.800 | from other tissues in the body.

00:27:31.880 | And one of the main hormones for that is luteinizing hormone.

00:27:35.560 | Luteinizing hormone, again, comes from the pituitary,

00:27:37.760 | circulates, and either goes to the ovary

00:27:40.280 | to promote various aspects of egg maturation,

00:27:45.280 | as well as production of estrogen,

00:27:48.080 | and to the testes to promote testosterone

00:27:51.440 | and sperm production.

00:27:53.140 | And the prescription version

00:27:56.800 | of increasing luteinizing hormone

00:27:59.420 | is something called HCG or human chorionic gonadotropin,

00:28:02.180 | which has been synthesized

00:28:03.340 | and is now available as a prescription drug.

00:28:05.900 | It's taken in various contexts for increasing fertility,

00:28:10.300 | both by males and by females.

00:28:12.460 | It can increase for all the reasons that now make sense.

00:28:16.120 | It can increase sperm production.

00:28:17.460 | It can produce ovulation frequency.

00:28:20.460 | It can produce the number of eggs

00:28:22.300 | even that are deployed in a given ovulation,

00:28:25.060 | although that's not always a good thing.

00:28:27.880 | It basically is pro-fertility, pro-testosterone,

00:28:31.480 | pro-estrogen, depending on your background.

00:28:34.400 | And what's interesting is HCG was initially synthesized,

00:28:39.400 | collected and synthesized from pregnant women's urine.

00:28:43.680 | And believe it or not, before it was synthetically made

00:28:48.440 | and sold as a prescription drug,

00:28:51.160 | there was actually a black market

00:28:53.200 | for pregnant women's urine where people would buy the urine.

00:28:56.700 | I don't know.

00:28:57.540 | I'm guessing that they probably just consumed it,

00:29:01.240 | which is weird.

00:29:02.080 | But in any case, human chorionic gonadotropin

00:29:05.640 | is now available as a prescription drug.

00:29:07.760 | And it's one of the things that many people use

00:29:10.000 | to increase testosterone or estrogen

00:29:12.600 | for increasing fertility.

00:29:14.220 | But there are certain supplements, not many,

00:29:16.800 | that apparently can increase luteinizing hormone

00:29:19.400 | and thereby can increase testosterone and estrogen.

00:29:22.400 | And one of the more well-documented ones

00:29:24.960 | is phytogia agrestis, that's F-A-D-O-G-I-A,

00:29:29.560 | separate word A-G-R-E-S-T-I-S,

00:29:33.320 | which at least according to the literature

00:29:36.320 | that I was able to find,

00:29:37.440 | can increase levels of luteinizing hormone

00:29:39.480 | and thereby levels of testosterone or levels of estrogen.

00:29:42.820 | The side effect profile of phytogia agrestis

00:29:45.160 | hasn't really been documented, so it's a little unclear.

00:29:48.400 | I just want to emphasize that anytime someone's going

00:29:51.720 | to start taking supplements

00:29:53.120 | or modifying sex steroid hormones,

00:29:55.760 | getting blood work done is extremely important

00:29:59.600 | for safety reasons and also just to know

00:30:01.220 | whether or not things are working.

00:30:02.980 | And because all of these things are subject

00:30:05.240 | to negative feedback, talked about this previously,

00:30:08.520 | previous episode, but if testosterone goes high or too high,

00:30:12.440 | it can feed back and shut down luteinizing hormone,

00:30:15.200 | which will then shut down for the testosterone production.

00:30:18.080 | Likewise, if estrogens are going too high

00:30:20.460 | or they're going too high at various phases of the cycle,

00:30:23.020 | that can start to throw off various other hormones,

00:30:26.320 | including FSH, progesterone, LH.

00:30:30.780 | The menstrual cycle itself is a just absolutely

00:30:33.460 | exquisite balance of feedback of luteinizing hormone

00:30:37.100 | kept low and constant,

00:30:38.380 | at least for the first 14 days of the cycle.

00:30:40.680 | Then mid cycle, there's a peak,

00:30:42.220 | and that's typically when ovulation occurs.

00:30:45.040 | That's why pregnancy is most likely

00:30:46.820 | during the middle of the 28-day cycle.

00:30:49.000 | FSH kind of goes up and then down across the first 14 days.

00:30:54.000 | So taking anything or really modifying one's estrogens

00:30:58.040 | or testosterone on that background of the menstrual cycle

00:31:01.240 | is really going to disrupt the way those things interact.

00:31:03.660 | And it's just such an exquisite feedback loop.

00:31:05.960 | So I'm not saying don't do that,

00:31:09.060 | but you definitely want to be aware of what you're doing.

00:31:11.720 | And blood draws are one way to do that.

00:31:13.720 | Monitoring cycles for ovulating females

00:31:16.660 | is another way to do that.

00:31:17.560 | And in males, having a good window

00:31:19.800 | into what's going on with testosterone,

00:31:21.480 | DHT, aromatase, estradiol, LH, et cetera, is just vital.

00:31:26.480 | And it's really part and parcel with the practice

00:31:30.640 | of thinking about optimizing these incredible things

00:31:33.220 | that we call sex steroid hormones,

00:31:34.840 | estrogen, and testosterone, and their derivatives.

00:31:37.240 | So once again,

00:31:38.060 | we covered a tremendous amount of information.

00:31:40.280 | I hope that you'll come away from this

00:31:42.080 | with a deeper mechanistic understanding

00:31:44.160 | of how the brain and body are interacting

00:31:47.040 | to control the output

00:31:49.080 | and the ways in which these incredible things

00:31:52.260 | that we call sex steroid hormones work and influence us.

00:31:55.480 | I hope you'll also come away with some ideas

00:31:57.160 | of things that you can do in particular behavioral practices

00:32:00.680 | that can improve sleep and your relationship to light,

00:32:03.640 | et cetera, because those things really set the foundation,

00:32:07.360 | not just for healthy steroid hormone output,

00:32:11.100 | but for all sorts of health effects

00:32:14.200 | and for both the psychology

00:32:16.300 | and the biology of your nervous system.

00:32:19.480 | In closing, I hope you'll leave today's episode

00:32:21.860 | with a much richer understanding of the mechanisms

00:32:24.580 | that control the endocrine and nervous system

00:32:26.680 | in the context of estrogen and testosterone,

00:32:29.360 | as well as take away various tools

00:32:31.340 | that you might choose to apply.

00:32:32.920 | And as always, thank you for your interest in science.

00:32:35.700 | [upbeat music]

00:32:38.280 | (upbeat music)

How to Optimize Testosterone & Estrogen | Huberman Lab Essentials

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