Pinto beans may help lower cholesterol

Elevated blood lipid levels increase risk of developing cardiovascular disease. Although cholesterol-lowering drugs are typically prescribed, a recent study by Dr. Vicki Schlegel and colleagues suggests that whole pinto beans may also effectively lower cholesterol.

By supplementing diets rich in saturated fat with whole pinto beans and their hulls, the researchers investigated changes in cholesterol metabolism and the molecular mechanisms responsible for the cholesterol-lowering effects.

The study results, published in the June 2019 issue of The Journal of Nutrition, suggest that pinto beans effectively lower cholesterol by decreasing cholesterol synthesis in the liver and cholesterol absorption in the small intestine.

Forty-four 9-wk-old male hamsters were randomly assigned into 4 groups based on diet, which included a normal-fat diet, a diet rich in saturated fat, a high saturated fat diet supplemented with whole pinto beans, and a high fat saturated fat diet supplement with pinto bean hulls. Plasma, liver, intestinal, and fecal samples were collected to evaluate multiple cholesterol markers and gene targets.

The plasma non-high-density lipoprotein concentration was significantly reduced in the whole pinto bean group and those fed pinto bean hulls by 31.9% and 53.6%, respectively, compared to hamsters fed diets high in saturated fats. Analyses of mechanistic pathways indicated that bioactive components present in pinto beans downregulated genes associated with cholesterol synthesis by the liver and cholesterol absorption by the small intestine. Another important cholesterol regulatory pathway, excretion of cholesterol via feces, was also reduced in hamsters fed diets supplemented with pinto beans.

The results of this study provide additional support for pinto beans as an effective cholesterol lowering agent. Another noteworthy finding was the cholesterol-lowering effect of pinto beans is partially exerted by hulls. Pinto beans can easily be incorporated into the everyday diet for the prevention of elevated cholesterol or for use as an adjunct therapy for those with existing hypercholesterolemia.

Reference
Nguyen AT, Althwab S, Qiu H, Zbasnik R, Urrea C, Carr TP, Schlegel V. Pinto Beans (Phaseolus vulgaris L.) Lower Non-HDL Cholesterol in Hamsters Fed a Diet Rich in Saturated Fat and Act on Genes Involved in Cholesterol Homeostasis. The Journal of Nutrition. 2019;149(6):906-1003. https://doi.org/10.1093/jn/nxz044