Consuming as little as one-half cup of cooked dry beans every day helped volunteers lower their total cholesterol levels in an Agricultural Research Service (ARS) study in North Dakota. These results, published in the November issue of the Journal of Nutrition by the ARS scientists and their colleagues, add to a growingand convincingbody of evidence that beans are a heart healthy food choice.
The lead authors, chemist Philip Reeves and nutritionist John Finley (no longer with ARS), conducted the study at the agency's Grand Forks Human Nutrition Research Center in Grand Forks, N.D. ARS is the U.S. Department of Agriculture's chief scientific research agency.
Experts consider a lipid profile, which provides a complete cholesterol count based on blood tests, to be a valid biomarker for the risk of cardiovascular disease. Because cardiovascular disease is a lifestyle-related disease, interventions that improve cholesterol profiles are considered beneficial to health. Positive changes in physical activity and diet may result in substantial improvements.
The researchers tested 80 volunteers aged 18 to 55 years. Half were healthy, while half had at least two symptoms that lead to metabolic syndrome, a combination of conditions that signal a risk for cardiovascular disease. Those with "pre-metabolic-syndrome" had abdominal obesity and either high triglyceride levels, low HDL "good" cholesterol, high blood sugar, or high blood pressure.
For 12 weeks, half of the group was randomly selected to eat one-half cup of cooked dry pinto beans daily along with their regular daily diet. The others ate a replacement serving of chicken soup instead of the pinto beans. The findings show that, compared to measures taken prior to the 12-week test phase, all the volunteersthe healthy ones as well as those with symptomswho ate pinto beans saw a reduction in their cholesterol levels.
While the findings confirm earlier studies by other researchers showing that eating beans lowers cholesterol levels, the mechanisms that underlie the effect require further study.