How Does Alcohol Increase the Risk of Cancer? | Dr. Andrew Huberman
00:00:00.000 | [silence]
00:00:03.240 | One of the really bad effects of alcohol,
00:00:05.720 | but that's extremely well-documented,
00:00:08.340 | is the fact that alcohol,
00:00:10.960 | because of this toxicity of acetyl aldehyde
00:00:13.720 | and related pathways, can alter DNA methylation.
00:00:17.200 | It can alter gene expression.
00:00:18.960 | That can mean many things in different tissues,
00:00:21.380 | but it is associated with a significant increase
00:00:26.380 | in cancer risk, in particular, breast cancer,
00:00:29.160 | and in particular, because breast tissue
00:00:31.720 | is present in both males and females,
00:00:33.240 | but in women, it's especially vulnerable
00:00:36.100 | to some of the DNA methylation changes.
00:00:38.560 | Well, breast cancer in women
00:00:40.820 | has a relationship to alcohol intake,
00:00:42.580 | and alcohol intake has a relationship
00:00:44.040 | to breast cancer in women.
00:00:45.820 | In fact, there has been proposed to be
00:00:50.160 | anywhere from four to 13% increase
00:00:53.860 | in risk of breast cancer
00:00:55.820 | for every 10 grams of alcohol consumed.
00:00:58.640 | How much is 10 grams?
00:00:59.880 | Well, there we need to think a little bit
00:01:01.480 | about the variation in the amount of alcohol
00:01:03.360 | in different drinks across the world.
00:01:05.000 | Different countries serve different sized drinks
00:01:06.880 | and have different concentrations of alcohol
00:01:08.440 | in those drinks.
00:01:09.440 | So without going down too much of a rabbit hole
00:01:11.720 | and just giving you some good rules of thumb to work with,
00:01:14.560 | there've been studies of the percentage of alcohol
00:01:17.760 | included in different drinks
00:01:18.840 | and the sizes of different drinks
00:01:20.180 | that are served in different countries,
00:01:21.360 | and here's a kind of a patchwork of those findings.
00:01:25.480 | In Japan, one beer, one glass of wine,
00:01:29.980 | or one shot of liquor as it's served there
00:01:32.800 | tends to include anywhere from seven to eight grams
00:01:35.480 | of alcohol.
00:01:36.920 | In the US, one beer, which generally is 12 ounces,
00:01:39.980 | if it's in a bottle,
00:01:42.080 | one glass of wine or a shot of liquor
00:01:45.440 | tends to include about 10 to 12 grams of alcohol.
00:01:50.440 | And in Russia, one drink of the various sorts
00:01:55.420 | that I just described,
00:01:57.360 | typically will have as much as 24 grams of alcohol
00:02:01.800 | because of the differences in the concentration of alcohols
00:02:05.520 | and the sizes of drinks that are poured
00:02:07.920 | in these different countries, okay?
00:02:09.560 | Of course, there are other countries in the world,
00:02:10.960 | those countries are also vitally important,
00:02:12.660 | but those are the ones that extracted from the studies
00:02:15.440 | that I could find.
00:02:16.400 | What does this mean?
00:02:18.760 | Well, what we're talking about
00:02:20.020 | is that for every 10 grams of alcohol consumed,
00:02:22.680 | so that's one beer in the US,
00:02:25.240 | maybe a little bit more than one beer in Japan,
00:02:27.640 | or basically a third of a drink in Russia,
00:02:31.640 | there's a four to 13% increase in risk of cancer.
00:02:36.640 | That's pretty outrageous, right?
00:02:39.360 | And you might think, wait,
00:02:40.240 | how could it be that this stuff is even legal?
00:02:43.360 | Well, look, as I described before, it's a toxin.
00:02:46.800 | It's also a toxin that people enjoy the effects of.
00:02:49.880 | I mean, in the US, at least they tried prohibition.
00:02:53.160 | It certainly did lead.
00:02:55.040 | Yes, did lead to a reduction
00:02:57.320 | in alcohol-induced health disorders,
00:03:00.760 | in particular cirrhosis of the liver.
00:03:02.240 | It also led to a lot of crime
00:03:03.920 | because it became a substance
00:03:05.740 | that a lot of people still wanted
00:03:07.760 | and that people were willing to break the law
00:03:09.980 | in order to provide, or I should say to sell and provide.
00:03:13.520 | But the point is that the more alcohol people drink,
00:03:16.940 | the greater their increase of cancer,
00:03:19.240 | in particular breast cancer.
00:03:20.360 | And that's because of the fact
00:03:22.400 | that alcohol has these effects on cells
00:03:26.200 | that include changes in gene expression.
00:03:29.280 | And cancer, that is the growth of tumors,
00:03:32.120 | is a dysregulation in cell cycles, right?
00:03:34.920 | A tumor is a aggregation or the proliferation.
00:03:38.260 | Aggregation is stuff sticking together, by the way.
00:03:40.280 | Proliferation is stuff duplicating.
00:03:42.880 | A proliferation and aggregation of cells
00:03:45.720 | that could be a glioma, is glial cells,
00:03:47.880 | glioma, brain tumor, right?
00:03:49.480 | It could be lymphoma, so within the lymph tissue, et cetera.
00:03:53.380 | The mutations that alcohol induces to cause this
00:03:56.680 | are wide ranging.
00:03:58.000 | Some of those are starting to start to be understood.
00:04:00.000 | For those of you that are interested in cell biology,
00:04:01.680 | I'll just mention that the PD-1 pathway,
00:04:04.240 | again, this is super specialized
00:04:06.920 | and for the aficionados only.
00:04:08.520 | You don't need to know this.
00:04:09.920 | The PD-1 pathway seems to be upregulated.
00:04:12.040 | And, and we knew this from the discussion earlier,
00:04:14.600 | there's a downregulation
00:04:16.200 | in some of the anti-inflammatory molecules
00:04:20.500 | that help suppress this proliferation of cancers.
00:04:24.120 | Nowadays, there's a lot of interest
00:04:25.480 | in the fact that the immune system
00:04:27.920 | is constantly combating cancers
00:04:30.100 | that exist in us all the time.
00:04:31.440 | You know, little tumors start growing
00:04:33.360 | and our immune system goes and gobbles them up.
00:04:35.400 | Little tumors start growing,
00:04:36.780 | the immune system senses inflammation,
00:04:38.620 | sends out these incredible cells,
00:04:40.040 | these killer B cells and T cells and beats them up.
00:04:44.060 | Cancers proliferate and take hold
00:04:46.380 | and cause serious problems
00:04:47.900 | when the proliferation of cells
00:04:50.020 | exceeds the immune system's ability
00:04:52.180 | to gobble up and remove those cells.
00:04:53.680 | There are other mechanisms of regulating cancers,
00:04:55.660 | but that's one of the primary one.
00:04:56.980 | And alcohol hits it, again, it's a two-hit model.
00:04:59.980 | It increases tumor growth
00:05:01.860 | and it decreases the sorts of molecules
00:05:05.380 | that suppress and combat tumor growth.
00:05:08.020 | So again, even low to moderate amounts of alcohol
00:05:11.460 | can be problematic for sake of cancers,
00:05:13.420 | in particular, breast cancers.
00:05:15.080 | Epidemiologists and health specialists
00:05:18.860 | love to try and compare different substances
00:05:21.460 | in terms of how bad they are.
00:05:23.020 | Rarely do they compare substances
00:05:25.040 | in terms of how good they are, but sometimes they do.
00:05:28.460 | And what they'll sometimes tell you
00:05:30.780 | and what you can find in the literature
00:05:32.100 | is that ingesting 10 to 15 grams of alcohol a day,
00:05:35.380 | so that would be like one beer in the US,
00:05:37.140 | one glass of wine,
00:05:38.220 | is the same as smoking 10 cigarettes a day.
00:05:41.260 | Frankly, it's hard to make that direct relationship
00:05:45.780 | really stick because it's a question of
00:05:48.780 | how long people inhale,
00:05:49.980 | do they have a predisposition to a lung cancer, et cetera.
00:05:53.320 | But even if that number is off
00:05:56.180 | by plus or minus two cigarettes,
00:05:59.400 | or even if that number would,
00:06:01.820 | the equivalent of one glass of wine
00:06:03.500 | equals one cigarette per day,
00:06:05.020 | I think there's general consensus now
00:06:07.180 | that nicotine consumed by vaping or by cigarette
00:06:11.240 | it's bad for us in terms of lung cancer
00:06:15.300 | and other forms of cancer.
00:06:16.780 | And for some reason, I don't know why,
00:06:19.260 | because this knowledge about alcohol and cancer
00:06:22.140 | and these established relationships
00:06:24.420 | have been known since the late 1980s.
00:06:26.620 | The first kind of landmark paper on this
00:06:28.980 | was published in 1987.
00:06:30.380 | I can provide a link to that paper,
00:06:31.540 | it's actually quite interesting to read.
00:06:34.580 | Well, the relationship is there
00:06:37.980 | and yet we don't often hear about it, right?
00:06:40.180 | In fact, before researching this episode,
00:06:42.320 | I had heard before that alcohol can increase cancer risk,
00:06:45.720 | but I wasn't aware of just how strong that relationship is.
00:06:49.040 | Because of the serious nature of what we're talking about
00:06:51.560 | and because I would hate to be confusing
00:06:54.540 | or misleading to anybody,
00:06:55.920 | I want to just emphasize that this statistic,
00:06:58.520 | that there is a four to 13%,
00:07:00.600 | depending on which study you look at,
00:07:02.000 | a four to 13% increase in the risk of cancer,
00:07:05.200 | in particular breast cancer,
00:07:06.440 | for every 10 grams of alcohol consumed,
00:07:09.940 | that's 10 grams per day.
00:07:11.480 | So that's one drink per day.
00:07:13.560 | But I do want to emphasize
00:07:15.720 | that if that equates to seven drinks per week
00:07:19.920 | and all those seven drinks are being consumed
00:07:22.540 | on Friday and Saturday,
00:07:23.920 | it still averages to 10 grams per day.
00:07:26.560 | And I also want to emphasize
00:07:27.880 | that there are things that people can do
00:07:29.840 | to at least partially offset
00:07:31.480 | some of the negative effects of alcohol
00:07:33.640 | as it relates to predisposition
00:07:36.080 | to the formation of certain kinds of tumors and cancers.
00:07:39.720 | I also want to be clear before I say it
00:07:42.220 | that doing the things I'm about to tell you
00:07:44.740 | is not a guarantee that you're not going to get cancer,
00:07:48.540 | nor is it a guarantee that alcohol
00:07:51.380 | is not going to lead to an increased predisposition
00:07:55.180 | for certain kinds of cancers.
00:07:56.620 | And the two things are consumption of folate
00:07:59.960 | and other B vitamins, especially B12.
00:08:03.180 | You know, the consumption of folate and B12
00:08:07.300 | has been shown to decrease cancer risk
00:08:09.720 | in people that ingest alcohol,
00:08:11.920 | but not completely offset it.
00:08:14.240 | Why that is isn't exactly clear.
00:08:16.180 | It probably has something to do
00:08:17.400 | with the relationship between folate and B12
00:08:20.760 | and other B vitamins in gene regulation pathways
00:08:24.440 | that can lead to tumor growth.
00:08:26.720 | At some point soon, we will get an expert in cancer biology
00:08:29.840 | and in particular in breast cancer biology on the program,
00:08:33.560 | and we can ask them about this.
00:08:35.160 | But I realize this is going to raise a number of questions
00:08:37.920 | and maybe even cause some of you to go out there
00:08:40.100 | and start taking folate and other B vitamins and B12.
00:08:43.500 | Not incidentally, a lot of the reported hangover supplements
00:08:49.420 | and treatments include folate and B12.
00:08:53.100 | I don't know if they had the cancer literature in mind
00:08:55.580 | when they created those supplements and products.
00:08:58.780 | I doubt they did.
00:09:00.620 | Alcohol really does disrupt B vitamin pathways,
00:09:03.980 | both synthesis pathways and utilization pathways.
00:09:07.000 | So sometimes you'll hear,
00:09:08.140 | oh, you know, if you get your B vitamins,
00:09:09.540 | it helps you recover from hangover more quickly.
00:09:13.020 | Again, the literature doesn't support that,
00:09:15.200 | but also again, there aren't a lot of studies,
00:09:17.300 | but more to the point as it relates to alcohol
00:09:20.820 | and the formation of tumors and cancers,
00:09:22.780 | it does appear that decreased folate
00:09:25.860 | and other B vitamins like B12 are partially responsible
00:09:29.500 | for the effect of alcohol and increasing cancer risk.
00:09:33.700 | And it does appear that consuming adequate amounts
00:09:38.020 | of folate and B12 might, again,
00:09:40.140 | might partially, I really want to bold face
00:09:42.820 | and underline and highlight,
00:09:44.020 | partially offset some of that increased risk.
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