“Western” and “prudent” dietary patterns are associated with breast cancer among Mexican pre- and postmenopausal women

Abstract

Breast cancer (BC) is the leading cancer worldwide among women. “Prudent” dietary patterns have been consistently and negatively associated with the risk of BC. However, prospective studies have shown a positive association between “Western” dietary patterns and the risk of BC, but only among postmenopausal women. In this regard, evidence from Latin America is scarce. Our aim was to assess the hypothesis that 2 dietary patterns (Western or prudent) were contrastingly associated with BC in pre- and postmenopausal women from Northern Mexico. We recruited 1045 BC incident cases and 1030 age matched (±5 years) population controls. Sociodemographic, reproductive, and dietary characteristics were obtained by direct interviews. We used a semiquantitative food frequency questionnaire to obtain information about diet 1 year before diagnosis for cases and 1 year before the interview for controls. Dietary patterns were identified through factor analysis. A Western-like pattern, which was mainly determined by positive loads in red and processed meats and foods rich in fats and sugars, was positively associated with BC both in pre- (odds ratio [OR] =23.47; 95% CI, 14.01-36.96) and in postmenopausal women (OR = 18.85; 95% CI, 13.74-25.87). In contrast, a prudent-like pattern, which was characterized by positive loads of vegetables, legumes, and corn, was negatively associated with pre- (OR = 0.35; 95% CI, 0.26-0.49) and postmenopausal BC (OR = 0.25; 95% CI, 0.19-0.32). Our results show the importance of dietary patterns in BC development regardless of menopausal status.