Remaining questions on moderate alcohol drinking and cancer risk

In a commentary piece published in the Journal ‘Cancer Causes, Control’, Edward Giovannucci of the Department of Nutrition and Epidemiology, Harvard TH Chan School of Public Health, Boston argues that while high levels of alcohol consumption are broadly recognised as harmful, the effects of low-to-moderate intake (up to 2 drinks/day for men and 1 for women) remain debated. Some studies suggest health benefits such as reduced cardiovascular disease and type 2 diabetes risk. However, these benefits are contested, and growing evidence shows that even modest alcohol use can increase the risk of certain cancers, particularly breast cancer in women. 25% of global alcohol-related cancer cases in 2020 occurred in people drinking at moderate levels. In moderate alcohol consumers, four modifying factors merit consideration: tobacco use, drinking frequency, whether drinking is with meals or on an empty stomach, and beverage type.
Smoking significantly amplifies the cancer risks associated with alcohol. A synergistic effect between alcohol and tobacco raises acetaldehyde levels and cancer risk, especially for upper aerodigestive tract cancers. Among non-smokers, moderate alcohol consumption contributes relatively little to cancer risk, particularly in men. However, in women, primarily due to breast cancer, risk increases even without smoking. These differences underline the need to assess alcohol-related cancer risk in the context of tobacco use.
How alcohol is consumed—regularly with meals versus infrequent binge drinking—substantially affects health outcomes. People with a “favourable” drinking pattern (regular, moderate intake with meals) show lower cancer and mortality risk compared to those with “unfavourable” patterns (e.g., binge drinking). Timing and frequency influence the body’s metabolic response and the exposure of organs to alcohol, particularly in the gastrointestinal tract.
Different types of alcoholic beverages may influence cancer risk differently. Red wine, for example, contains phenolic compounds like resveratrol that may offer protective effects against oxidative stress and metabolic dysfunction. Observational and interventional studies suggest that red wine may be less harmful—or even beneficial—in some contexts compared with liquor or beer. Breast cancer risk, however, remains significant regardless of beverage type.
Giovannucci concludes that current public health recommendations often generalise alcohol risk by average daily intake, without accounting for key modifiers such as smoking, drinking patterns, meal timing, and beverage type. These factors can significantly alter the relationship between alcohol and cancer risk. For truly informed guidance on low-to-moderate alcohol use, future research must better account for these variables and explore biologically plausible mechanisms, rather than relying on simplistic dose–response models.
Source: Giovannucci, E. Commentary: remaining questions on moderate alcohol drinking and cancer risk. Cancer Causes Control, 2025, 36:743–745,