Legume consumption is inversely associated with type 2 diabetes incidence in adults: A prospective assessment from the PREDIMED study.

Summary Background & aims Legumes, a low-energy, nutrient-dense and low glycemic indexfood, have shown beneficial effects on glycemic control and adiposity. As such, legumesare widely recommended in diabetic diets, even though there is little evidence that their consumption protects against type 2 diabetes. Therefore the aim of the present study was to examine the associations between consumption of total legumesand specific subtypes, and type 2 diabetesrisk. We also investigated the effect of theoretically substituting legumesfor other protein- or carbohydrate-rich foods. Methods Prospective assessment of 3349 participants in the PREvencion con DIeta MEDiterranea ( PREDIMED) study without type 2 diabetesat baseline. Dietary information was assessed at baseline and yearly during follow-up. We used Cox regression models to estimate hazard ratios (HRs) and 95% confidence intervals (95% CIs) for type-2 diabetesincidence according to quartilesof cumulative average consumption of total legumes, lentils, chickpeas, dry beans and fresh peas. Results During a median follow-up of 4.3 years, 266 new cases of type 2 diabetesoccurred. Individuals in the highest quartileof total legumeand lentil consumption had a lower riskof diabetes than those in the lowest quartile(HR: 0.65; 95% CI: 0.43, 0.96; P- trend = 0.04; and HR: 0.67; 95% CI: 0.46–0.98; P- trend = 0.05, respectively). A borderline significant association was also observed for chickpeas consumption (HR 0.68; 95% CI: 0.46, 1.00; P -trend = 0.06). Substitutions of half a serving/day of legumesfor similar servings of eggs, bread, rice or baked potato was associated with lower riskof diabetes incidence. Conclusions A frequent consumption of legumes, particularly lentils, in the context of a Mediterranean diet, may provide benefits on type 2 diabetesprevention in older adults at high cardiovascular risk. Trial registration The trial is registered at http://www.controlled-trials.com (ISRCTN35739639). Registration date: 5th October 2005.