Health Benefits of Legumes
Legumes are members of the pea family (Fabaceae or Leguminosae). Often just the bean is consumed, but sometimes it is consumed with the pod, as in the case of snow peas or green beans. These latter edible-podded legumes are classified as vegetables (because of their culinary and nutritional properties), so here, let’s hone in on pulse-type legumes, i.e., beans!
Across studies, beans have demonstrated a great number of health benefits, likely due to their combination of fiber and phytonutrients. A high consumption of beans is associated with a lower risk of all-cause mortality, reduced waist size, lower risk of obesity, and lower systolic blood pressure. In a cross-cultural study of adults in Japan, Sweden, Greece, and Australia, legume consumption was the only consistent significant predictor of longer lifespan (a 7% to 8% reduction in mortality hazard ratio for every 20 grams increase of daily legume consumption)! And in animal models, beans (especially black beans and navy beans) have demonstrated potential anti-cancer properties for colon tumor growth.
In epidemiological studies, consumption of legumes is frequently associated with better health and greater longevity. This is attributable to their amazing nutrient-density (especially fiber, vitamins and minerals) and the fact that they’re particularly great for increasing growth of probiotic bacteria in our guts. A large 2017 meta-analysis showed that all-cause mortality (a general indicator of health and longevity) decreased by 16% with increasing intake of legumes up to 150 grams (3 servings) per day. And, in a 2021 study, eating 3+ servings of legumes per week reduces all-cause mortality by 17% compared to 2 servings per month, also lowering cardiovascular disease mortality, cancer incidence and cancer mortality.
For example, lentils and peas have been shown to protect against cardiovascular disease, with cholesterol-lowering effects being attributed to their soluble fiber, oligosaccharide, isoflavone, and phospholipid content; lentils and peas alike possess ACE inhibitor activity, contributing to their blood-pressure lowering activity. Lentils have also been shown to improve glycemic control among diabetics, and encourage lower food intake (due to promoting satiety), while peas and legumes both have anti-cancer activities related to their polyphenol and saponin content.
Importantly, beans can be a fantastic food for supporting gut health. In rats, researchers tested the effects of fiber and resistant starch on the gut microbiota by feeding animals isocaloric diets containing peas, common beans, garbanzo beans, lentils, or a control diet with casein and cellulose. The legumes were all cooked and freeze-dried before use in the study. After 28 days, all legumes resulted in lower counts of Enterobacter and Bacteroides compared to the casein/cellulose control.
Examples of Legumes
- black bean
- black-eyed pea
- common bean
- cranberry bean
- fava bean
- Great Northern bean
- kidney bean
- lima bean
- navy bean
- mung bean
- pigeon pea
- pinto bean
- runner bean
Nutrients in Legumes
Expand to see all scientific references for this article.
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Darmadi-Blackberry, I., M.L. Wahlqvist, A. Kouris-Blazos, et al. 2004. “Legumes: the most important dietary predictor of survival in older people of different ethnicities.” Asia Pacific Journal Clinic of Nutrition. 13(2):217-220.
Li, H., J. Li, Y. Shen, J. Wang, and D. Zhou. 2017. “Legume Consumption and All-Cause and Cardiovascular Disease Mortality.” BioMed Research International. 2017:8450618. doi:10.1155/2017/8450618.
Liu W, Hu B, Dehghan M, Mente A, Wang C, Yan R, Rangarajan S, Tse LA, Yusuf S, Liu X, Wang Y, Qiang D, Hu L, Han A, Tang X, Liu L, Li W; PURE-China Investigators. Fruit, vegetable, and legume intake and the risk of all-cause, cardiovascular, and cancer mortality: A prospective study. Clin Nutr. 2021 Jun;40(6):4316-4323. doi: 10.1016/j.clnu.2021.01.016.
Monk, J.M., D. Lepp, W. Wu, K.P. Pauls, L.E. Robinson, and K.A. Power. 2017. “Navy and black bean supplementation primes the colonic mucosal microenvironment to improve gut health.” Journal of Nutritional Biochemistry. 49:89-100. doi:10.1016/j.jnutbio.2017.08.002.
Monk, J.M., D. Lepp, W. Wu; et al. 2017. “Chickpea-supplemented diet alters the gut microbiome and enhances gut barrier integrity in C57Bl/6 male mice.” Journal of Functional Foods. 38:663-674. doi:10.1016/j.jff.2017.02.002.
Papanikolaou, Y., and V.L. Fulgoni III. 2008. “Bean Consumption Is Associated with Greater Nutrient Intake, Reduced Systolic Blood Pressure, Lower Body Weight, and a Smaller Waist Circumference in Adults: Results from the National Health and Nutrition Examination Survey 1999-2002.” Journal of the American College of Nutrition. 27(5):569-576. doi:10.1080/07315724.2008.10719740.
Schwingshackl L, Schwedhelm C, Hoffmann G, Lampousi AM, Knüppel S, Iqbal K, Bechthold A, Schlesinger S, Boeing H. Food groups and risk of all-cause mortality: a systematic review and meta-analysis of prospective studies. Am J Clin Nutr. 2017 Jun;105(6):1462-1473. doi: 10.3945/ajcn.117.153148.