International Journal of Epidemiology

The role of diet in breast cancer aetiology is unclear; recent studies have suggested associations may differ by estrogen receptor status. In this large prospective study LEAP, a consortium brought together by the Oxford Martin Programme on the Future of Food, systematically examined associations of 10 foods and eight macronutrients with breast cancer risk, overall and by estrogen receptor status.

The strongest finding was a positive association of alcohol consumption with breast cancer risk, in line with previous evidence. None of the 17 other foods and macronutrients examined was strongly associated with breast cancer risk; both fruit and fibre intakes, which are correlated, showed inverse associations with risk, but it is unclear if these associations are causal.