The association between alcohol and breast cancer risk: Evidence from the combined analysis of six dietary case‐control studies

Data from 1,575 cases and 1,974 controls enrolled in 6 previously conducted case‐control studies of diet and breast cancer have been analysed with respect to alcohol intake. There appears to be an absence of any association between consumption of up to 40 g of alcohol per day and risk of breast cancer, and a highly statistically significant and consistent elevated risk of breast cancer for drinkers of 40 g or more of alcohol per day, for whom the relative risk, as compared with that of non‐drinkers, is 1.69 (95% confidence interval 1.19 to 2.40). This association is not due to confounding by a number of diet‐related factors, including total calories, fat, fibre and vitamin C.