Alcohol Consumption by Beverage Type and Risk of Breast Cancer: A Dose-Response Meta-Analysis of Prospective Cohort Studies.
Level 3 - non-randomized controlled study
Systematic review and meta-analysis of prospective cohort studies (Level 3 evidence)
PubMed 32090238 · doi:10.1093/alcalc/agaa012
What was done
A systematic review and dose-response meta-analysis of prospective cohort studies retrieved from PubMed and Web of Science up to December 1, 2018. Researchers evaluated 22 cohort studies comprising 45,350 breast cancer cases to calculate summary relative risks (RRs) and attributable risk percentages (ARPs) for total alcohol and beverage types (beer, wine, spirits), with subgroup analyses across estrogen receptor (ER) status, menopausal status, and geographical region.
What was found
Linear dose-response analysis demonstrated that breast cancer risk increased progressively with higher consumption of total alcohol and wine: - Total alcohol: Each additional 10 g/day increased risk by 10.5% (RR = 1.10, 95% CI 1.08–1.13). - Wine: Each additional 10 g/day increased risk by 8.9% (RR = 1.08, 95% CI 1.04–1.14); the abstract reports that among specific beverage types, only wine showed this similar significant effect (no numerical estimates provided for beer or spirits). - Postmenopausal women: Risk increased by 11.1% per 10 g/day increase in total alcohol (RR = 1.11, 95% CI 1.09–1.13). - Receptor status: Current drinkers had elevated risk compared with never drinkers specifically for ER+ breast cancer. - Region: The alcohol-attributable percentage was higher in Europe than in North America and Asia.
Why it matters
This meta-analysis quantifies a linear ~9–11% breast cancer risk increase per 10 g/day of total alcohol or wine, underscoring that risk begins at modest daily intakes and is particularly pronounced for postmenopausal and ER-positive disease.
Limits
The underlying studies are observational cohorts susceptible to residual confounding from diet, parity, hormone therapy, and other lifestyle factors. Alcohol consumption was self-reported, risking measurement error and underreporting. Numerical effect sizes and confidence intervals for beer and spirits were not reported in the abstract.
Cited by
- supports Alcohol consumption is classified as a Group 1 carcinogen and increases the risk of developing breast cancer.