Healthnotes Newswire (December 6, 2001)—Eating more legumes, such as beans and peas, reduces the risk of coronary heart disease (CHD), according to a study recently published in the Archives of Internal Medicine.¹ The new research, based on data culled from the First National Health and Nutrition Examination Survey (NHANES I), is the first to examine the relationship between dietary legume intake and the development of CHD.

A total of 9,632 men and women participated in the study. The frequency of their legume consumption was estimated by a three-month food frequency questionnaire. Respondents were asked how often "dry beans and peas like pinto beans, red beans, black-eye [sic] peas, peanuts, and peanut butter" were usually consumed. The incidence of CHD and cardiovascular disease (CVD) death and hospital admissions was tracked as well. Eating legumes four times a week or more compared with less than once per week was associated with a 22% lower risk of CHD and an 11% lower risk of CVD.

CHD is the single largest killer of men in the United States and one of the leading causes of permanent disability. CHD-related medical expenses among Medicare beneficiaries alone exceeds $10 billion per year.² Primary prevention of CHD is a major public health issue in the United States and worldwide.

Why beans?

Legumes are high in several constituents, such as soluble fiber, that have been linked to benefits in the cardiovascular system. Soluble fiber has been shown to lower total and low-density lipoprotein (LDL, or "bad") cholesterol.³

Legumes are also a major dietary source of folic acid, which is important for reducing the levels of homocysteine in the blood. Homocysteine is a toxic amino acid byproduct that is not meant to accumulate unchecked in the body. Rather, homocysteine needs to be transformed into safer amino acids, such as methionine and cysteine. High homocysteine levels increase the risk of cardiovascular disease, as well as many other diseases.

Legumes are generally low in sodium and high in other minerals, like potassium, calcium, and magnesium. Low sodium intake and high dietary intake of potassium, calcium, and magnesium reduce the risk of CVD.^{4 5 6}

Other constituents might also contribute to the protective effects of legumes against CVD. For example, soybean protein has been shown to reduce total cholesterol, LDL cholesterol and triglycerides in an analysis of 29 clinical trials.⁷ This review also found that substituting protein from vegetable sources, particularly soybeans, for protein from animal sources lowers blood cholesterol levels.

The results of the study emphasize the importance of including legumes in a balanced diet as a way of preventing heart disease. An easy way to increase the amount of legumes consumed is to replace animal protein with beans or bean products (e.g., tofu, tempeh) a couple of times per week.