Legume intake and cancer risk in a network of case-control studies

Evidence on the relationship between legume consumption and risk of specific cancer sites is inconclusive. We used data from a series of case-controls studies, conducted in Italy and in the Swiss Canton of Vaud between 1991 and 2009 to quantify the association between legume consumption and several cancer sites including oral cavity, esophagus, larynx, stomach, colorectum, breast, endometrium, ovary, prostate and kidney. Multiple logistic regression models controlled for sex, age, education, smoking, alcohol, body mass index, physical activity, comorbidities, and consumption of fruit, vegetables, processed meat and total calorie intake were used to estimate the odds ratios (OR) for different cancer sites and their corresponding 95% confidence intervals(CI). For female hormone-related cancers, the models also included adjustments for age at menarche, menopausal status and parity. Although most of the estimates were below unity, suggesting a protective effect, only colorectal cancer showed a significant association. Compared to no consumption, the OR for consuming at least one portion of legumes was 0.79 (95% CI: 0.68-0.91), the OR for consuming two or more portions was 0.68 (95% CI: 0.57-0.82) and the estimate for an increment of one portion per week was 0.87 (95% CI: 0.81-0.93). The inverse association between legume consumption and colorectal cancer suggests a possible role of legumes in preventing cancer risk.