How Cavities Form & How to Prevent Them

00:00:00.000 | Okay, let's talk about how cavities form,

00:00:05.080 | because I think this is the major question

00:00:06.840 | that people ask when asking about

00:00:09.500 | or thinking about oral health.

00:00:11.200 | As I mentioned before, cavities are literally holes,

00:00:13.760 | they're fenestrations, as the nerds call them,

00:00:17.280 | nerds like me call them.

00:00:18.840 | Little fenestrations, little holes down into the enamel

00:00:21.160 | that if they make it down to the dentin layer of the tooth,

00:00:23.440 | most likely do need to be drilled and filled

00:00:27.720 | and presumably billed, okay?

00:00:30.560 | But your goal, I think all of our goal

00:00:32.880 | is to try and keep our teeth

00:00:34.720 | in a state of remineralization by keeping the pH,

00:00:39.040 | that is the relative acid-alkaline balance of the mouth,

00:00:43.600 | such that the saliva supports remineralization.

00:00:47.300 | Now, let's think about how a cavity actually forms.

00:00:51.040 | Turns out that no specific food,

00:00:54.320 | not even sugar, causes cavities.

00:00:56.980 | Cavities are not caused by sugar.

00:00:59.680 | Cavities are caused by bacteria that feed on sugar.

00:01:04.240 | And now that's not just a little bit

00:01:05.400 | of a twist in the mechanism, that's a critical point.

00:01:09.120 | There's no specific food, not even pure sugar,

00:01:12.360 | not even like a hard candy, like a delicious Jolly Rancher,

00:01:15.680 | I used to like those when I was a kid,

00:01:17.240 | that gets stuck in your tooth that causes cavities.

00:01:19.520 | No, it's the bacteria that feed on sugar

00:01:23.160 | that then produce acid that burrows down through,

00:01:27.460 | that degrades, that demineralizes the tooth

00:01:31.020 | in this very focal area that we call a cavity, okay?

00:01:35.340 | Now, if that isn't surprising enough, get this.

00:01:38.620 | The bacteria that causes cavities by eating sugar

00:01:43.580 | and releasing this acid, while there are several of them,

00:01:46.500 | the major one is called streptococcus mutans,

00:01:48.740 | or what I'll call strep mutans for short.

00:01:52.020 | Strep mutans is not something you're born with.

00:01:54.780 | It's actually a communicable bacteria.

00:01:58.560 | That's right, you give it to one another through how?

00:02:01.760 | Sharing of glasses, sharing of bottles,

00:02:04.940 | kissing on the mouth, et cetera.

00:02:07.600 | Now, I am not here to tell you not to do any of those things.

00:02:10.600 | I'm certainly not here to tell you that.

00:02:12.840 | However, and by the way, in researching this episode,

00:02:16.020 | I did learn that there is a specific category

00:02:18.040 | of person out there.

00:02:19.000 | Typically, they are a dentist or married to a dentist.

00:02:21.920 | That have opted, believe it or not,

00:02:23.980 | to never kiss their children near or on the mouth

00:02:27.460 | so as to help their children not get streptococcus mutans

00:02:32.220 | because almost all adults carry it, not all,

00:02:34.640 | but it's communicable like a STI or like a flu

00:02:38.720 | or like a cold.

00:02:39.560 | It's communicated between individuals.

00:02:41.480 | We are not born with it.

00:02:42.480 | Now, that's a whole area of,

00:02:44.680 | let's just call it bio-social ethics decision-making

00:02:49.000 | that I think most people are not going to be too concerned

00:02:51.900 | with or at least act on because let's face it,

00:02:55.720 | most people are not going to change their overall behavior

00:02:59.480 | of kissing or usage of bottles or glasses

00:03:04.080 | in order to avoid getting strep mutans.

00:03:05.660 | Most people in the world have strep mutans

00:03:08.080 | or will get strep mutans and it lives in the mouth, okay?

00:03:12.140 | It just resides there.

00:03:13.320 | Strep mutans is there and it's hungry.

00:03:16.780 | What's it hungry for?

00:03:17.760 | Sugar.

00:03:19.320 | When there's sugar present, it eats it, it produces acid.

00:03:23.380 | The acid produces cavities,

00:03:25.060 | taking teeth from a state of remineralization

00:03:28.780 | to demineralization or, and by the way,

00:03:31.060 | this is really important.

00:03:31.940 | If your mouth is already in a state

00:03:34.380 | that's more demineralization mode, so to speak,

00:03:39.380 | well, then it will capitalize on that

00:03:42.460 | and it will cause cavities much faster, okay?

00:03:46.140 | So keep in mind that acidity is bad for the mouth.

00:03:50.320 | Does that mean that you should never consume a lemon or,

00:03:53.360 | and by the way, yes, I'm guilty of every once in a while

00:03:55.400 | I'll chew a lemon slice or drinking water with lemon in it

00:03:58.280 | or carbonated drinks or sodas or tea

00:04:01.760 | or anything that has acidic flavor?

00:04:04.100 | No.

00:04:04.940 | Likewise, should you completely avoid ingesting

00:04:07.880 | any kind of sugar because strep mutans love sugar?

00:04:11.440 | No.

00:04:12.280 | It turns out strep mutans like sugars

00:04:13.680 | in the form of complex carbohydrate sugars too.

00:04:16.280 | So if you eat pasta or rice or oatmeal

00:04:19.080 | and some bread every once in a while, as I do,

00:04:21.240 | I'm an omnivore, I eat meat and fish and eggs

00:04:23.680 | and also starches and vegetables and fruits.

00:04:25.960 | I'm an omnivore, as most people are.

00:04:29.400 | Well, then strep mutans has an opportunity

00:04:31.380 | to eat the sugars that come from those other carbohydrates.

00:04:34.180 | Does that mean that if you were to have

00:04:35.560 | a zero carbohydrate diet, no sugars, no starches, et cetera,

00:04:39.080 | you would reduce the opportunity for strep mutans

00:04:42.880 | to consume sugar and release acid?

00:04:45.640 | Maybe, maybe.

00:04:47.480 | However, most people won't do that.

00:04:49.640 | And strep mutans is a very clever,

00:04:52.160 | maybe even diabolical bacteria.

00:04:53.880 | And if you were on a zero carbohydrate, zero sugar diet,

00:04:56.240 | there's some evidence that strep mutans

00:04:57.960 | will figure out ways to feed on other components of food

00:05:02.440 | in order to create this acid

00:05:04.220 | to then create cavities in your teeth.

00:05:06.460 | So the key thing to understand here

00:05:08.160 | is that cavities form not from foods,

00:05:10.800 | not from sugars per se,

00:05:12.760 | but from strep mutans and other bacteria

00:05:15.020 | that eat those sugars and create acid.

00:05:16.920 | Hence the critical need to keep your mouth

00:05:19.720 | as alkaline as possible,

00:05:21.160 | which does not mean that you can ever drink

00:05:23.320 | some lemon water or coffee or tea.

00:05:25.240 | Here's the key point that everyone needs to remember,

00:05:27.760 | because this dovetails beautifully

00:05:29.280 | into how often you should brush and floss

00:05:31.640 | and when you should brush and floss specifically.

00:05:34.180 | The key point is the degree to which your mouth

00:05:37.520 | is in a de-min state or a re-min state,

00:05:40.280 | and the degree to which cavities

00:05:42.840 | have the opportunity to form

00:05:44.240 | is dependent on the amount of time,

00:05:46.900 | the amount of time in which your mouth

00:05:49.640 | is net acidic or net alkaline,

00:05:52.680 | the amount of time that you are in a de-mineralization mode

00:05:56.760 | or re-mineralization mode.

00:05:59.320 | Okay, so it's the amount of time.

00:06:01.280 | No one, no one can avoid

00:06:04.120 | having their mouth be acidic every once in a while

00:06:06.160 | or ingesting a sugar or a food that strep mutans

00:06:09.400 | can feed on and produce acid.

00:06:11.000 | The key is to try and reduce the amount of strep mutans

00:06:14.120 | and reduce the amount of acid in the mouth.

00:06:17.400 | That's the best way to reduce cavities

00:06:19.600 | and even reverse cavities that have started to form.

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How Cavities Form & How to Prevent Them | Dr. Andrew Huberman

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