What’s the Truth About Alcohol, Cancer, and Your Health?
there’s a significant need for nuance and care in interpreting these findings. The relationship between alcohol and cancer is complex, and while it may be prudent to raise awareness about potential risks, it’s critical to approach this issue with a careful understanding of the data.
Alcohol ambivalence has been with us for almost as long as alcohol itself. In fact, quote, “It is hard to say whether wine does good to more people than it harms. Medical opinion is very divided,” end quote. Who do you think said that? It sounds like something Surgeon General Vivek Murthy might say in 2024, but it was actually the Roman author Pliny the Elder writing in the first century AD, according to a very plain language translation.
More than 400 years before Pliny, Eubilus, a Greek comic poet of the fourth century BCE, remarked that, quote, “Although two bowls of wine bring love and pleasure, five lead to shouting, nine lead to bile, and ten produce outright madness in that it makes people throw things.” End quote. The question of how much alcohol is good for us is one we’ve been grappling with for at least 2,400 years.
In the late 20th century, however, conventional wisdom shifted dramatically in favor of the idea that moderate drinking, especially red wine, was beneficial to health. In 1991, Morley Safer, a correspondent for CBS, recorded a segment for 60 Minutes titled “The French Paradox.” In it, he highlighted how the French, despite their rich diets filled with meat and fats, managed to live longer with lower rates of cardiovascular disease compared to Americans or their northern European peers.
For years, it became widely accepted among doctors in many countries that alcohol, particularly red wine, could lower the risk of heart disease. This notion seemed to be confirmed as research indicated that wine affects the platelets, the smallest of the blood cells, leading to a flushing effect that potentially aids arterial health. Following this report, the demand for wine in the U.S. soared, with red wine purchases reportedly climbing by 40% in the years that followed. The idea that a glass of red wine each night was akin to taking heart medicine became a universally embraced belief.
However, this belief had its critics, who pointed out the need for further understanding. Over time, the idea that moderate drinking is unambiguously good for one’s health became entrenched in science and popular culture, to the point where doubting the protective effects of alcohol was likened to conspiracy theories. Tim Stockwell, a behavioral psychologist and health researcher in Canada, once scoffed at the need for more research, noting the growing body of J-shaped curve studies that suggested light to moderate drinking extended life expectancy.
The J-curve became a celebrated construct in health research. However, Stockwell’s perspective evolved, leading him to join a growing number of researchers questioning the validity of the J-curve. To understand why, one must recognize that many of these conclusions stemmed from averaging results from multiple observational studies. As Stockwell explained, observational studies involve examining people over a prolonged period, collecting data about their behaviors, backgrounds, and health statuses, but they inherently lack control groups, making definitive conclusions difficult.
While these studies can yield valuable insights, they often oversimplify complex relationships. This was exemplified by studies that correlated mouthwash use with mouth cancer. As researchers later discovered, it wasn’t the mouthwash causing cancer but rather a confounding factor related to poor dental hygiene and unhealthy behaviors.
When applying this logic to alcohol, it became clear that conclusions derived from the J-curve might also be overly simplistic. Moderate drinkers might have healthier profiles for myriad reasons unrelated to their alcohol consumption. This inherent complexity in public health data means that drawing firm conclusions about alcohol consumption and health can be fraught with challenges.
In light of these revelations, Stockwell and his team undertook an extensive review of health studies. In their analysis, they discovered two critical truths: first, that moderate drinkers could be healthier for reasons unrelated to their alcohol use, and second, that many non-drinkers were not abstaining for health-related reasons but rather because of prior health issues.
This led to a staggering conclusion—the J-curve, long thought to represent a protective effect from moderate drinking, effectively vanished. Stockwell’s research suggested that moderate drinking does not provide the previously assumed benefits and may even carry increased risks for certain conditions, such as cardiovascular disease and cancer.
As our understanding of alcohol’s health implications evolved, public health messages began to shift. In Canada, guidelines recommending safe levels of drinking have drastically changed. From endorsing up to 15 drinks a week for men to now suggesting no more than two drinks per week, the advice reflects a growing consensus in the health community.
Simultaneously, the U.S. Surgeon General’s recent report on alcohol aimed to raise awareness about cancer risks associated with drinking. While the report is well-intentioned, it underscores the complexities involved in the relationship between moderate drinking and cancer.
The nuances of alcohol consumption, health risk, and cultural perceptions are vast and merit careful examination. For those navigating this terrain, it becomes essential to parse through conflicting data with a discerning eye, recognizing that the story of alcohol is one steeped in history, complexity, and constant inquiry. The journey to understanding the impact of moderate drinking is far from over, and a balanced approach is crucial as we strive to navigate personal and public health outcomes. is that if you enjoy a glass of wine each evening, you might be trading a few months of life expectancy for the pleasures and social interactions that come with it.
It’s important always in this space to distinguish between absolute risk and relative risk. Owning a swimming pool dramatically increases the relative risk that somebody in the house will drown. But the absolute risk of drowning in your own backyard swimming pool is blessedly low.
And in a similar way, some analyses have concluded that moderate drinking can increase a person’s odds of getting mouth cancer by about 40%. That sounds pretty dramatic. But the lifetime absolute risk of developing mouth cancer is less than 1%. That means one drink per day increases the typical individual’s chance of developing mouth cancer by 0.3 percentage points. Very low.
The Surgeon General report also says that moderate drinking, say one drink per night, increases the relative risk of a woman getting breast cancer by 10 to 20%. Again, that sounds pretty dramatic. But it only raises the absolute lifetime risk of getting breast cancer from about 11% to 13%. Assuming the math is sound, I think that’s a good thing to know. But if you pass this information along to a friend, I think it’s okay if they say, sorry, I like drinking Chardonnay on Tuesdays more than I fear a two percentage point increase in my odds of getting breast cancer in 20 years, which by the way is a percentage point increase with a low confidence interval.
Now there’s one more claim about alcohol and health that I didn’t have a chance to cover in my Atlantic essay and I want to cover here. If you’re in the health and wellness and self-optimization space, you’ve probably heard about another finding, which is that alcohol, even small amounts of it, can cause brain degeneration. Here’s the celebrity psychiatrist, Dr. Daniel Amen, on the Diary of a CEO podcast.
Alcohol causes damage in the brain. Really? Even a little bit of alcohol causes damage in the brain. It disrupts something called white matter. So gray matter, nerve cell bodies, white matter, nerve cell tracks. So white matter is the highways in your brain that transmit information and impulses. And even a little bit of alcohol has been shown to disrupt the white matter in your brain.
Is this right? Does even a little bit of alcohol disrupt the white matter in your brain? Well, let’s look at it. The title of the study in question is Associations Between Alcohol Consumption and Gray and White Matter Volumes in the UK Biobank. It’s a mouthful, but we’ll add a link in the show notes. What the study did is it got tens of thousands of healthy middle-aged and older adults in the UK. It asked them how much alcohol they drank. It gave them MRIs to look at the white and gray matter levels in their brain. And then it found the association.
What they found, in fact, was a positive association between self-reported drinking and reduced volume of white matter and gray matter even at low levels of drinking. All right? It’s a good study. It clearly shows this strong link, especially between heavy alcohol use and brain degeneration. But there’s at least two problems with saying that this study proves that a glass of wine a night is killing your white and gray matter.
First, the study relied on self-reports, as many of these observational studies do. And there are minimal controls for what participants define as one unit of alcohol. Right? You’re taking this large group of people, some of whom are having a big martini every night, and some of whom are, like, cracking open a beer that they don’t finish while they watch NBC primetime. And both those individuals might self-report, I had one drink a night, but they’re consuming a wildly different amount of alcohol, which is going to muddy the final data.
Second, the strongest effect size by far in this study was for folks who had more than three or four drinks a day. In one table in the paper, the authors actually did something kind of nice. They calculated the equivalent effect of brain aging in terms of additional years for an average 50-year-old individual. So this is smart. It’s kind of like, how fast is your drinking habit aging your brain? And they calculated that people who have four drinks a day are increasing this one measure of brain aging by 10 years. So when they turn 50, their brain will turn 60.
That’s for people having four, five, six drinks a day. But what about people having one drink a day? Well, after excluding the heavy drinkers from the analysis and rerunning the regression, the authors found that one drink a day increases your brain age by four or five months by the time you turn 50. So I’m thinking about this for my own life, right? I was born in May. I turned 50 in 2036. My body will turn 50 that May. According to this study, my brain will turn 50 in January.
Should that discovery get me to stop drinking wine forever? I think it’s fine to be crystal clear about the health effects of moderate drinking, but if my brain’s going to turn 50 the same year my body turns 50, but just like a few months earlier, that is a much more acceptable risk to me than some of the fear-mongering that I hear among health influencers for anybody who has a glass of wine at night.
So, to sum up, because this has been a lot of information, there was an old conventional wisdom represented by the J-curve that moderate drinking was clearly good for you. But this was based on observational studies that had a ton of problems, especially in that moderate drinkers were healthier for reasons that had nothing to do with their drinking, and non-drinkers are often less healthy for reasons that had nothing to do with their abstinence.
When you failed to control for this, well then, of course, the moderate drinkers looked healthier. But when the J-curve died, when it went away, it was replaced by a new, emerging conventional wisdom that now is telling us that moderate drinking is dangerous. And I think that conventional wisdom is also overconfident. It includes frequent warnings about the effects of moderate drinking on cancer rates and brain health that I think are worth noting, but I think also misrepresent in the media the effect size of moderate drinking on cancer mortality and brain disease, an effect size which is often very, very low.
So where does this leave us? Well, for Tim Stockwell, the upshot is pretty simple. The safest thing to do now is just to assume there’s some slight risks if you drink a little bit and it’s up to you whether you take those risks. Look, I think that’s fair. But I also think that life isn’t—or at least it should not be—about avoiding every single activity that has the tiniest amount of risk. Cookies have risk. Going out into the sun, going to the beach has risk. Trying to bench your body weight when you have a bad shoulder has risk. Getting in a car to go hang out with a friend. All of these involve a real possibility of risk and injury.
So I pressed Tim to define his most cautious conclusions in a memorable way. A way that I could remember after our conversation even if I felt he might be overconfident in his caution. One drink a day for men or women will reduce your life expectancy on average by about three months. If I have the math right, every drink reduces your expected longevity by about five minutes. Does that seem about accurate? Yeah, that’s the same as just saying the same thing in a different way. You look at all the minutes that you might live; the average person lives, and all the drinks they might consume over a life course. At a low level of drinking, we calculate about five minutes of life lost every time you take a drink.
If you drink at a heavier level, you know, two or three drinks a day, that goes up to like 10, 15, or 20 minutes per drink—not per drinking day, but per drink. Every drink takes five minutes off your life. It’s hard to forget that one. Every drink takes five minutes off your life. Now maybe the thought scares you, but personally and honestly, I find comfort in it, even as I think it probably suffers from the same flaws of overconfidence that plague this entire field.
Several months ago, I had the Stanford University scientist Ewan Ashley on this podcast. He studies the cellular effects of exercise, and if you recall, Ewan told me that according to the observational data that he consulted, one minute of exercise adds five minutes to your expected lifespan. This data is based on a population of more than half a million people, so that’s pretty big, who were followed for over 10 years.
The investigators basically looked at the amount of exercise that was done, which was generally moderate to higher intensity exercise—like a brisk walk plus—and considered the number of minutes every day that those people exercised followed by how long they lived. There was a very clear correlation. When you looked at how much that exercise bought you in terms of extra life, it indeed mapped out: one minute of exercise at a brisk walking pace would buy you five minutes. In fact, if you exercised at a higher intensity, you could get seven or eight minutes of extra life.
So, check this out: when you put these two statistics together—Tim Stockwell and Ewan Ashley—you get the following lovely bit of longevity math for moderate drinkers. Every drink reduces your life by the same five minutes that one minute of exercise can add back to your life. Right? Now there’s a motto for healthy moderation: have a drink, have a jog. But I think even this kind of arithmetic can absolutely miss a bigger point and a deeper point.
I want to end here by quoting the article that I wrote for the Atlantic because I tried very, very hard to capture in words something more profound about this whole exercise. To reduce our existence to a mere game of minutes gained and lost is to squeeze the life out of life. Alcohol is not a vitamin or a pill that we swiftly consume in the solitude of our bathrooms, which could be straightforwardly evaluated in a controlled lab setting. At best, moderate alcohol consumption is enmeshed in activities that we share with other people: cooking, dinners, parties, happy hours, celebrations, rituals, get-togethers—life.
It is pleasure, and it is people; a social mortar for our age of social isolation. An underrated aspect of the Surgeon General’s report is that it is following rather than trailblazing a national shift away from alcohol. As recently as 2005, Americans were more likely to say alcohol was good for them than bad; last year they were five times more likely to say it was bad than good.
In the first seven months of 2024, alcohol sales declined for beer, wine, and spirits, and the decline seems especially pronounced among young people. To the extent that alcohol carries a serious risk of excess and addiction, less booze in America seems purely positive. But healthy drinking is social drinking, and the decline of alcohol seems related to the fact that Americans now spend less time socializing face-to-face than in any period in modern history.
Some Americans are trading the blurry haze of intoxication for the crystal clarity of sobriety. This might be a blessing for their minds or their guts, but in some cases, they may be trading an ancient drug of socialization for the novel intoxicants of isolation.
Thank you for listening. We’ll talk to you next week, and I’ll see you next week. Next week, next week, next week, we’ll see you next week. You next week. Bye.