How risky is that pint of beer? Report links alcohol to increased cancer risk

In his final weeks as U.S. surgeon general, Vivek Murthy released his Parting Prescription for America, a 30-page document that urges the American people to look for connection, purpose, and service for a happier and healthier life. That message, however, was overshadowed by another of Murthy's prescriptions, given a few days earlier, on Jan. 3: Reduce alcohol consumption to reduce risk of cancer. Come together, the advisories seem to say—just not over a pint.

According to the Office of the Surgeon General, less than 50% of Americans are aware that alcohol increases their risk of cancer, despite the growing body of evidence. To increase awareness, Murthy suggests updating the warning label on alcoholic beverages to state the cancer risk, akin to what we're used to seeing on packs of cigarettes.

This comes after a paper published by a working group of the World Health Organization's International Agency for Research on Cancer (IARC) reported that quitting or reducing alcohol consumption reduced the risk of a striking list of cancers.

"They concluded that there was a high likelihood—and there's good scientific correlation to suggest—that alcohol causes breast cancer, colon cancer, rectal cancer, esophageal cancer, and liver cancer," says Otis Brawley, a Johns Hopkins Bloomberg Distinguished Professor of oncology and epidemiology and associate director of community outreach and engagement at the Sidney Kimmel Comprehensive Cancer Center. "We have known since the 1920s that alcohol, especially hard alcohol, causes cancer, but no one had brought together all the literature."

Still, Brawley notes that he's encountered a lot of "shock" and disbelief surrounding the recent advisory.

"The precautionary principle is, if it might cause cancer, you should warn people that it might cause cancer. Now, this is not a 'might cause cancer.' This is 'it does cause cancer.' Therefore, many of us feel that we should be warning people," Brawley says.

An estimated 741,300 cancer cases in 2020 were linked to alcohol consumption. It is ranked the third leading preventable cause of cancer.

Research shows that alcohol can cause cancer by breaking down into a metabolite that ultimately damages your DNA, which can lead to the formation of tumors. And the effects of alcohol seem to compound. One of the studies that the IARC working group looked at found that the absolute risk of developing alcohol-related cancer among women rose nearly 3% for individuals who drank daily versus those who drank fewer than one drink per week.

But when it comes to risk involved in something we enjoy, how does that affect our personal decisions? Is a beer safer than a martini? What about red wine, which has been raised up for its heart-healthy benefits? The Hub caught up with Brawley about the risk of imbibing.

What does this research tell us about the risk involved in drinking alcohol?

I'll tell you that the concept of carcinogenicity is not to eliminate all carcinogens entirely, but to try to manage exposure to them. [The IARC] came to the conclusion that spirits and hard alcohol are worse, but wine and beer are not safe.

The analogy I would [give] is, I walked across Charles Street earlier today. If you cross a busy street, you are putting your life at risk. You are taking a chance. Now, you know you're taking a chance, and you've made a calculation that crossing the street with adequate safeguards is worthwhile.

I want people to be able to go to a cocktail party, enjoy a glass of red wine or white wine and realize it's not totally safe. But I also want them to know that drinking three or four is worse. Binge drinking is clearly worse than mild-to-moderate drinking.

What effect does stopping drinking have on that risk?

Research shows that quitting drinking reduces the risk of esophagus and oral cavity cancers. But for several of the cancers [like pharynx and liver cancer] in this paper, they actually said, "We have evidence that drinking increases the risk of this cancer. We don't have as strong evidence that to stop drinking reduces the risk." I can't say cessation does not reduce risk; I can just say we don't have the scientific evidence to prove it.

What amount of alcohol would you recommend as safer to your patients?

I would recommend that if you choose to drink, please do it in moderation. Moderation is one drink or less a day for women, two drinks or fewer a day for men. (A drink is defined as a jigger of hard alcohol, 5 ounces of wine, or 12 ounces of beer.) Just realize you do increase your risk of a number of cancers by doing that. You also increase your risk of stomach ulcers. But it's a mild increase at best and may very well be worth the pleasure associated with [drinking].

What questions do you still have, as an oncologist, about alcohol and cancer risk?

I would still be interested in [learning more about] the question of spirits versus wine versus beer. I would also be interested in learning the relative risk of red wine usage for causing cancer versus reducing cardiovascular disease risk. IARC believes there is no net benefit. Others have suggested there may be one .

How likely is it that a warning label would result in a change in consumer behavior?

Probably not much. It might reduce the number of binge drinkers. I especially worry about teenagers and young adults binge drinking. What I want is for people to stop expressing shock and surprise when told that alcohol consumption increases the risk of cancer.