Flavonoids and lignans are bioactive polyphenols that are contained in plant based foods such as fruits, vegetables, nuts, legumes, cocoa, and cereals, and in beverages such as tea, wine, and juices. It has been proposed to have a potential role in the prevention of type 2 diabetes through diverse biological effects, including antioxidant and anti-inflammatory properties and insulin sensitivity enhancing effects.

The EPIC-InterAct study, the European Prospective Investigation into Cancer and Nutrition-InterAct case-cohort study included 12,403 incident type 2 diabetes cases and a stratified sub cohort of 16,154 participants. At baseline, country-specific validated dietary questionnaires were used. A flavonoid and lignan food composition database was developed from the Phenol-Explorer, the U.K. Food Standards Agency, and the U.S. Department of Agriculture databases. On analysis, a trend for an inverse association between total flavonoid intake and type 2 diabetes was observed but not with lignans. This suggests a potential protective role of eating a diet rich in flavonoids, a dietary pattern based on plant based foods, in the prevention of type 2 diabetes.