Pinto beans are one of the finest alternative vegetarian protein sources. 100 grams of pinto beans carry 347 calories, and 21.47 g or 38% of recommended daily values of protein.
The beans are moderate sources of antioxidant isoflavones. Total isoflavones is 0.18 mg per 100 grams of beans; daidzein and genistein at levels 0.01 mg and 0.17 mg respectively. Isoflavones have been found to reduce post-menopausal cancers and osteoporosis.
Pinto beans are minor sources of O-methylated isoflavone compound, Biochanin-A (0.28 mg per 100 g). Biochanin-A is a plant-estrogen. Studies suggest that it plays a definitive role in anti-cancer diet programs.