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

Abstract Evidence on the relationship between legume consumption and risk of specific cancer sites is inconclusive. We used data from a network 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 and consumption of fruit, vegetables, processed meat and total calorie intake were used to estimate the odds ratios (OR) of different cancer sites and their corresponding 95% confidence intervals(CI). For female hormone-related cancers, the models included also adjustments for age at menarche, menopausal status and parity. For all cancer sites considered, except endometrium, the OR for ≥ 2 portions of legumes per week vs < 1 portion were below unity, and were significant for oral cavity (OR: 0.71, 95% CI: 0.52–0.97), esophagus (OR: 0.50, 95% CI: 0.29–0.86), larynx (OR: 0.55, 95% CI: 0.34–0.89), colorectum (OR: 0.70, 95% CI: 0.58–0.83) and kidney (OR: 0.69, 95% CI: 0.49–0.95). For esophagus, colorectal, ovarian and kidney cancers we found a significant trend (OR for 1 portion per week: 0.82,0.88, 0.89 and 0.88 respectively. The analysis stratified by sex showed that most associations were limited to men. The inverse association found for several cancers suggest a possible role of legumes in preventing cancer risk. The sex-specific pattern of association requires further research.