Previous studies have shown that heavy drinking increases the risk of certain cancers, including breast, colon, liver and mouth cancers. But according to a new study, even light to moderate consumption of alcohol is associated with an increased risk of cancer.
A Large Cohort Study
The study was done as a collaboration between the Harvard T.H. Chan School of Public Health in Boston, and Brigham and Women’s Hospital, also in Boston, Massachusetts. The team of researchers used data from two large U.S. studies that tracked the health of 88,084 women and 47,881 men for up to 30 years.
They then assessed the risk of total cancer as well as other known alcohol-related cancers including colorectum cancer, female breast cancer, liver, oral cavity, pharynx, larynx and esophagus cancer.
The researchers then correlated the data compensating for such influential variables as age, ethnicity, body mass index, family history of cancer, history of cancer screening, smoking, physical activity and diet were also taken into account.
Definition of Light and Moderate
Light to moderate drinking is defined as up to one standard drink (15 grams of alcohol) per day for women and up to two standard drinks (30 grams of alcohol) per day for men. One drink is roughly equivalent to a small (118 milliliter) glass of wine or a (355 milliliter) bottle of beer.
Results
During the follow-up period, a total of 19,269 women and 7,571 men were diagnosed with cancer. The data indicates that light to moderate drinking was associated with a small but statistically non-significant increased risk of total cancer in both men and women, regardless of smoking history.
But for alcohol-related cancers specifically, the risk was increased among light and moderate drinking men who had ever smoked, but not among men who never smoked. For a woman, the risk increased for both those who had ever smoked and those that had never smoked. The risk of alcohol-related cancers such as breast cancer increased even with light drinking, up to one drink per day.
So even light and moderate drinking was associated with an increased risk of certain alcohol-related cancers in both male and woman smokers. And for a woman, the risk of alcohol-related cancers increased for both smokers and nonsmokers.
The study Light to moderate intake of alcohol, drinking patterns, and risk of cancer: results from two prospective US cohort studies has been published in The British Medical Journal.
Objectives
To quantify risk of overall cancer across all levels of alcohol consumption among women and men separately, with a focus on light to moderate drinking and never smokers; and assess the influence of drinking patterns on overall cancer risk.
Design
Two prospective cohort studies.
Setting
Health professionals in the United States.
Participants
88 084 women and 47 881 men participating in the Nurses’ Health Study (from 1980) and Health Professionals Follow-up Study (from 1986), followed until 2010.
Main outcomes and measures
Relative risks of cancer.
Results
19 269 and 7571 (excluding non-advanced prostate cancers) incident cancers were documented among women and men, respectively, over 3 144 853 person years. Compared with non-drinkers, light to moderate drinkers had relative risks of total cancer of 1.02 (95% confidence interval 0.98 to 1.06) and 1.04 (1.00 to 1.09; Ptrend=0.12) for alcohol intake of 0.1-4.9 and 5-14.9 g/day among women, respectively. Corresponding values for men were 1.03 (0.96 to 1.11), 1.05 (0.97 to 1.12), and 1.06 (0.98 to 1.15; Ptrend=0.31) for alcohol intake of 0.1-4.9, 5-14.9, and 15-29.9 g/day, respectively. Associations for light to moderate drinking and total cancer were similar among ever or never smokers, although alcohol consumption above moderate levels (in particular ≥30 g/day) was more strongly associated with risk of total cancer among ever smokers than never smokers. For a priori defined alcohol related cancers in men, risk was not appreciably increased for light and moderate drinkers who never smoked (Ptrend=0.18). However, for women, even an alcohol consumption of 5-14.9 g/day was associated with increased risk of alcohol related cancer (relative risk 1.13 (95% confidence interval 1.06 to 1.20)), driven by breast cancer. More frequent and heavy episodic drinking was not further associated with risk of total cancer after adjusting for total alcohol intake.
Conclusion
Light to moderate drinking is associated with minimally increased risk of overall cancer. For men who have never smoked, risk of alcohol related cancers is not appreciably increased for light and moderate drinking (up to two drinks per day). However, for women who have never smoked, risk of alcohol related cancers (mainly breast cancer) increases even within the range of up to one alcoholic drink a day.
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Light to moderate intake of alcohol, drinking patterns, and risk of cancer: results from two prospective US cohort studies
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