By Mark Gold, MD
Cancer is a serious public health risk, and approximately 7 million deaths per year around the world are attributed to smoking each year. In recent decades we have come to better understand the link between smoking and cancer; 22% of all cancers are linked to a person’s smoking and 70% of people globally now understand that link, up from just 40% in 1966. This relationship has often clouded a discussion of cancer risks. But as far as we have come in understanding how smoking, genetics, and even stress affect our chances of developing life-threatening cancers, we still understand very little about the relationship between alcohol and cancer. Only 13% of adults surveyed in the UK believe that cancer is a health risk of drinking alcohol, despite research linking it directly to multiple different forms of cancer that affect both men and women. Smoking and drinking both have second-hand effects to consider as well - 40,000 deaths each year attributed to non-smokers exposed to smoke. Alcohol and its effects on drivers is also significant, as auto and motorcycle traffic injuries are the ninth cause of death across all age groups, globally, and many are alcohol and/or drug-related. Despite a decrease in driving under the influence of alcohol prevalence over the past decades, DUIA prevalence still remains very high in the United States.1
Cancer and alcohol, both highly prevalent and societally expensive, pose public health risks in their own right, but recent research shows that drinking may compound the risks of cancer. Researchers at the University of Southampton recently found that alcohol is a powerful carcinogen - and even very moderate drinking can have a profound impact, comparable to smoking, on a person’s likelihood to develop cancer.
What did the study find about the link between alcohol and cancer?
This study found that even moderate levels of drinking, measured as one bottle of wine per week, increased the likelihood of men and women developing cancer - and women experienced an increased likelihood that was double that of men who drank a comparable amount, with an increased lifetime risk of 1.0% for men and 1.4% for women.
This increased risk of drinking one bottle of wine per week, for women, was equivalent to the increased risk of smoking 10 cigarettes; for men, it was equivalent to 5. These researchers also found that as consumption increases, so does risk. Alcohol consumption of three bottles of wine per week is associated with a 1.9% increased lifetime risk for men, and a 3.6% lifetime risk increase for women. To put that into perspective, if 1,000 men and 1,000 women each drank 3 bottles of wine a week, 19 men and 36 women would develop cancer as a result - similar numbers as you would find in men who smoke 10 cigarettes a week, and women who smoke 30.
Driving a large portion of the increased risk in women was a disproportionately increased risk of developing breast cancer - a 0.08% risk for moderate drinkers, and a 2.4% increase in risk for heavy drinkers. This study also found that while men are more affected by tobacco, alcohol, even moderately consumed, affected women more strongly.
Note: As the above figures show, smoking does not affect the body in the same way as alcohol, and the researchers are not equating the effects - cigarettes merely give a well-understood point of comparison, as most people understand that cigarettes are directly linked to cancer, while many don’t understand the same causal link with alcohol.
Why are these findings important?
Alcohol, like smoking, is a major cause of morbidity and mortality. They are extremely dangerous on a global scale. Each year harmful alcohol use kills 3.3 million people, accounting for 5.9% of all deaths - and the increase in cancer deaths that add to this death toll has yet to be measured. Despite it being well understood that heavy drinking is not good for your health, there is little understanding about the effects that moderate drinking can have on your health as well - some even believing, despite the robust evidence against the belief - that moderate consumption of alcohol is good for your health. This research, showing that even moderate drinking can increase the lifetime risk of cancer, reinforces the recommendation of the World Health Organization and the International Agency for Research on Cancer, that there is no safe amount of alcohol.
This study, appears to conflict with earlier data from Harvard and elsewhere on reductions in all cause mortality among drinkers.2 Guidelines suggesting safe levels of drinking have also confused both consumers and experts. These data, however, suggest that even moderate consumers increase your cancer risks and reinforces alcohol as a public health concern. In addition to all its other known health effects, the lifetime risk increase of cancer is an important but often overlooked consideration when educating both youth and adults about the possible ramifications of even moderate alcohol use. Women who drink are especially at risk, in large part due to the increased breast cancer risks.3 It is a good time to do what NIAAA calls “re-thinking drinking”. Just like reducing alcohol intake, or harm reduction point of view, encouraging people who drink alcohol to pick for beverages with lower alcohol content, harm reduction is also a key strategy in lowering people’s risk of developing alcohol-associated cancers.
References:
( Park J.Y., Wu L.T., (May 4, 2019) Trends and correlates of driving under the influence of alcohol among different types of adult substance users in the United States: a national survey study. BMC Public Health
Rimm, E.B. Giovanucci, E.L. Willett, W.C., Et al. (1991) Prospective study of alcohol consumption and risk of coronary disease in men. Lancet
Meyer, S.B., Foley, K., Olver, I., Ward, P.R., McNaughton, D., Mwanri, L., Miller. E.R., (2019) Alcohol and breast cancer risk: Middle-aged women’s logic and recommendations for reducing consumption in Australia. PLOS ONE
Citation:
Hydes, T.J., Burton, Inskip, R.H., Bellis, M.A., Sheron, N., (2019). A comparison of gender-linked population cancer risks between alcohol and tobacco: how many cigarettes are there in a bottle of wine? BMC Public Health
Dr. Mark S. Gold is a teacher of the year, translational researcher, author, mentor and inventor best known for his work on the brain systems underlying the effects of opiate drugs, cocaine and food. Read more by Dr. Gold here.