Despite alarming figures and trends, public awareness of alcohol as a carcinogen remains low.
In 1988, alcohol was designated as a carcinogen by the International Agency for Research on Cancer.1 It and its by-products have been identified as contributors to the development of at least 7 cancers including oropharynx, larynx, esophageal squamous cell, liver, colon, rectum and breast. Other types, such as gastric, pancreatic, and lung cancer, are being considered for inclusion in the list.2 Globally, alcohol contributes to 4.1% of all cancers, modeled to be 741,300 potentially avoidable cancer cases.3
Alcohol use increased dramatically among US women during the COVID-19 pandemic due to greater uncertainty and stress around providing care for dependents.4
Since the pandemic began, we have seen more cases of alcoholic hepatitis and liver transplants as a result of alcohol use. Regrettably, this will lead to more alcohol-associated cancers in approximately 10 to 20 years. We know from prior catastrophic events, like Hurricane Katrina5 and the 9/11 attacks, that increased alcoholic intake will continue after the inciting incident has passed.6
Despite these alarming figures and trends, public awareness of alcohol as a carcinogen remains low, according to surveys by the National Cancer Institute, the American Society of Clinical Oncology, and others.7,8 Only about 30% of Americans know that alcohol is a carcinogen and that risk varies by beverage type compared with those who understand that UV light (63%) and cigarettes (81%) increase the risk of cancer. Even more alarming, these surveys showed that some individuals believe alcohol may prevent cancer.7,8
The reason to increase awareness—aside from motivating individual change—is that those who realize that alcohol is a carcinogen are more likely to support policies to control alcohol consumption.9
Physicians, especially oncologists, rarely discuss alcohol use with patients.10 An illuminating series by Mother Jones staff reporter Stephanie Mencimer discusses the questions she was asked and dietary counseling she received about breast cancer.11 Unlike tofu and broccoli, alcohol was never mentioned. The alcohol she had been consuming, as she says in the series, might have contributed to her breast cancer, and she would have liked to have known about this risk. If we don’t ask about it, patients may not realize the significance of alcohol intake. Briefly asking how much alcohol a patient consumes can have a positive impact on patient behavior.
People probably don’t know about the risks posed by alcohol because of studies that say small amounts of red wine, which contains resveratrol, may be good for the heart. This has resulted in large epidemiologic studies showing a J-shaped curve, with lower cardiovascular mortality rates among low-level drinkers than among nondrinkers.12
However, if we look at all-cause mortality and not just cardiovascular risk, other studies demonstrate that there is no safe amount of alcohol consumption.3 A recent meta-analysis by Zhao et al has shown that the problem with such epidemiologic studies resides in the control group. Individuals who currently abstain but used to drink (sometimes called sick quitters) are very different from lifelong abstainers.13
Individuals who don’t drink now because of comorbid illness, medication(s), or prior problematic use may have sustained damage from prior consumption or have higher risk due to concurrent illness that drives mortality or cardiovascular risk. This group of individuals should not be included in the same control group as those who never drank or drank very rarely over their lifetime. As Zhao et al showed, when the control arm consists of only those who rarely or never drank, the J-shaped curve disappears.
For decades oncologists have been able to state definitively that to prevent cancer, no amount of regular alcohol consumption is safe. Now, we can also say that regular alcohol intake does not appear to confer any cardioprotective benefit.
Noelle LoConte, MD, FASCO, is an associate professor at the University of Wisconsin School of Medicine and Public Health and Outreach Program Leader at UW Carbone Cancer Center in Madison.