Light to moderate intake of alcohol, drinking patterns, and risk of cancer: results from two prospective US cohort studies.
Level 3 - non-randomized controlled study
Prospective longitudinal cohort study
PubMed 26286216 · doi:10.1136/bmj.h4238
What was done
Researchers tracked 88,084 women from the Nurses' Health Study (1980–2010) and 47,881 men from the Health Professionals Follow-up Study (1986–2010) over 3,144,853 person-years. The study evaluated relative risks (RR) of total incident cancer and a priori defined alcohol-related cancers across levels of alcohol intake and drinking patterns, stratified by smoking status.
What was found
During follow-up, 19,269 incident cancers in women and 7,571 in men (excluding non-advanced prostate cancers) were documented. Compared with non-drinkers, light to moderate drinking had relative risks of total cancer of 1.02 (95% CI 0.98 to 1.06) for 0.1–4.9 g/day and 1.04 (95% CI 1.00 to 1.09; P trend = 0.12) for 5–14.9 g/day in women. In men, RRs for total cancer were 1.03 (0.96 to 1.11) for 0.1–4.9 g/day, 1.05 (0.97 to 1.12) for 5–14.9 g/day, and 1.06 (0.98 to 1.15; P trend = 0.31) for 15–29.9 g/day. For alcohol-related cancers among never-smoking men, light-to-moderate drinking showed no significant increase (P trend = 0.18). In never-smoking women, alcohol intake of 5–14.9 g/day was associated with an increased risk of alcohol-related cancer (RR 1.13, 95% CI 1.06 to 1.20), driven largely by breast cancer. Heavy episodic drinking frequency showed no extra association after adjusting for total intake.
Why it matters
It demonstrates sex-specific differences in alcohol-associated cancer risk, showing that even light-to-moderate drinking (up to one drink daily) is linked to elevated alcohol-related cancer risk in women due to breast cancer, whereas risk in never-smoking men is not appreciably elevated at moderate levels.
Limits
The study relies on self-reported dietary questionnaires, which are susceptible to measurement error and recall bias. The cohorts consisted entirely of US health professionals, limiting generalizability to broader or more socioeconomically diverse populations, and observational analyses remain vulnerable to residual confounding.
Cited by
- supports Consuming more than one alcoholic drink per night is associated with a higher incidence of cancers, especially in women.