Beans & Heart Health

Beans are simply delicious, naturally nutritious food that promotes heart health because of what they contain (fiber and potassium) as well as what they don’t contain (no saturated fat, trans fat, cholesterol, or sodium).

Maintaining healthy blood pressure levels promotes heart health and reduces risk of cardiovascular disease and stroke. The D.A.S.H. (Dietary Approaches to Stop Hypertension) study found that a diet lower in sodium and rich in fruits, vegetables, legumes, fat-free and low-fat dairy, whole grains foods, fish, poultry, seeds, and unsalted nuts reduced blood pressure compared to the control diet, which was modeled after the typical American diet. (Moore et al, 1999) Many of the food groups included in the D.A.S.H. eating plan are natural sources of potassium, including beans.

Legumes like dry beans have been shown to improve serum lipid profiles in patients with coronary heart disease (CHD). (Anderson, 2002, Bazzano, 2011) A growing body of evidence supports the positive the effects of dietary legume consumption on health, particularly in relation to risk for CHD.

One epidemiological study has directly examined the relationship between bean consumption and occurrence of cardiovascular disease. Kabagambe et al. (2005) reported that one serving (1/2 cup) per day of beans was associated with a 38% lower risk of myocardial infarction (a.k.a. heart attack), while more than one serving per day did not provide any further decreased risk.

Bazzano et al (2001) reported that individuals consuming legumes at least four times per week had a 22% lower risk of heart disease than individuals consuming legumes less than once per week. In the epidemiological studies where legumes are consumed as part of a healthier diet plan, consistent reductions in heart disease risk have also been observed. In the Health Professionals Follow-up Study, men who adhered to a more “prudent” diet that included greater consumption of whole grains, legumes, fish, and poultry had a 30% lower risk of heart disease. Conversely, individuals following a more “Western” diet, characterized by increased consumption of red meat, refined grains, sweets, French fries, and high fat desserts had a higher risk of heart disease. (Hu, 2000) Similar trends were seen in the Nurses Health Study. Those who consistently ate the “prudent” diet had half the risk of developing heart disease compared to those that most often ate the “Western” diet. (Fung, 2001)

Data from several human intervention trials indicate that consumption of canned and cooked beans reduces serum cholesterol. Eleven (11) studies found small, but statistically significant reductions in total and LDL cholesterol by eating beans. (Anderson, 1987; Shutler, 1989; Anderson, 1999; Winham, 2007; Simpson, 1981; Jenkins, 1983; Anderson, 1990; Bingwen, 1981; Jimenez-Cruz, 2004; Winham, 2007; Finley, 2007)

Epidemiologic studies support the cardioprotective effects of legumes as part of a healthy diet. In particular, one study examined the relationship between bean consumption and occurrence of cardiovascular disease (CVD) and reported that one serving (1/2 cup) per day of beans was associated with a 38% lower risk of myocardial infarction. (Kabagambe, 2005) A second study reported that individuals consuming legumes at least four times per week had a 22% lower risk of heart disease than individuals consuming legumes less than once per week. (Bazzano, 2001)

The number of randomized, crossover research studies that have examined the effects of legumes on blood cholesterol levels is increasing. Many of the initial trials included legumes as only one part of a high-plant, low-cholesterol-type diet. However, more recent studies have focused on the cholesterol lowering effects of legumes as part of a controlled or normal diet. Overall, data from these studies indicate that consumption of canned or cooked beans will lower total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) levels. (Anderson, 1987; Anderson, 1999; Shutler, 1989; Winham, 2007a; Anderson, 1990; Bingwen, 1981; Finley, 2007; Jenkins, 1983; Jimenez-Cruz, 2004; Simpson, 1981; Winham, 2007b; Jenkins, 1983; Anderson, 1984)

The amount of legumes used in these feeding studies has generally ranged from ½ cup to 1 cup per day, which fits within the NCEP ATP III guidelines. Reductions in TC and LDL-C have varied from 5-8% in the studies that had participants consume ½ cup of legumes (Winham, 2007; Jenkins, 1983) to 19-24% when 1 cup per day was consumed. (Anderson, 1990; Anderson, 1984)

There are several possible mechanisms that may explain the cholesterol lowering effects of legumes.

  1. Saturated fat displacement from the diet
  2. Viscous fibers binding to dietary cholesterol in the intestine
  3. Interruption of bile acid enterohepatic circulation
  4. Inhibition of endogenous cholesterol synthesis by short chain fatty acids (SCFA)

However, it has yet to be determined which mechanism or combination of mechanisms is responsible for the legumes’ cholesterol lowering abilities. Overall, research studies support the benefits of legumes in promoting heart health.

Legumes are inexpensive, readily available, and have been shown to reduce blood cholesterol. Making simple dietary changes to include increased legume consumption to improve risk for CHD appears very practical compared to more traditional interventions like drug therapy. It should be noted that some individuals, particularly those with excessively elevated serum lipoprotein profiles and genetic predisposal to lipid abnormalities, will likely require the help of medications such as statins, to achieve normal, healthy serum lipoprotein profiles. However, this type of therapy does not appear to be optimal for everyone due to safety concerns and cost constraints (National Cholesterol Education Program, 2002). Therefore, individuals who do not require the use of such medications should be encouraged to make reasonable diet and physical activity changes, as they are generally safer, more affordable and provide a wide array of health benefits.

Additionally, eating beans may provide protection from cardiovascular disease beyond what can be explained by a small depression in blood cholesterol (Kabagambe, 2005). It is possible that the wide variety of phytochemicals in beans provide protection against developing cardiovascular disease, and studies are beginning to explore these additional protective properties.

It is essential that the current recommendations established by governmental agencies for increased, frequent legume consumption be conveyed to the public, who can use this simple dietary modification to improve their health.

REFERENCES

Anderson JW, Gustafson NJ, Spencer DB, Tietyen J, Bryant CA. Serum lipid response of hypercholesterolemic men to single and divided doses of canned beans. Am J Clin Nutr. 1990;51:1013-1019.

Anderson JW, Major AW. Pulses and lipaemia, short- and long-term effect: Potential in the prevention of cardiovascular disease. Br J Nutr. 2002;88(Suppl 3):S263-S271.

Anderson JW, Ratliff P. High-carbohydrate, high-fiber diets decrease insulin requirements of type-1 diabetic individuals. Clin Res. 1987;35(6):A898-A898.

Anderson JW, Smith BM, Washnock CS. Cardiovascular and renal benefits of dry bean and soybean intake. Am J Clin Nutr. 1999;70(3):464S-474S

Anderson JW, Story L, Sieling B, Chen W-JL, Petro MS, Story J. Hypocholesterolemic effects of oat-bran or bean intake for hypercholesterolemic men. Am J Clin Nutr. 1984;40:1146-1155.

Bazzano LA, He J, Ogden LG, et al. Legume consumption and risk of coronary heart disease in US men and women. Arch Intern Med. 2001;161(21):2573-2578.

Bazzano LA, Thompson AM, Tees MT, Nguyen CH, Winham DM. Non-soy legume consumption lowers cholesterol levels: a meta-analysis of randomized controlled trials. Nutr Metab Cardiovasc Dis. 2011; 21(2):94-103.

Bingwen L, Zhaofeng W, Wanzhen L, Rongjue Z. Effects of bean meal on serum cholesterol and triglycerides. Chinese Med J. 1981;94:455-458.

Finley JW, Burrell JB, Reeves PG. Pinto bean consumption changes SCFA profiles in fecal fermentations, bacterial populations of the lower bowel, and lipid profiles in blood of humans. J Nutr. 2007;137(11):2391-2398.

Fung TT, Willett WC, Stampfer MJ, Manson JE, Hu FB. Dietary patterns and the risk of coronary heart disease in women. Archives of Internal Medicine. 2001;161(15):1857-1862.

Hu FB, Rimm EB, Stampfer MJ, Ascherio A, Spiegelman D, Willett WC. Prospective study of major dietary patterns and risk of coronary heart disease in men. American Journal of Clinical Nutrition. 2000;72(4):912- 921.

Jenkins DJA, Wolever TMS, Jenkins AL, et al. The glycemic index of foods tested in diabetic-patients – a new basis for carbohydrate exchange favoring the use of legumes. Diabetologia. 1983;24(4):257-264.

Jenkins DJ, Wong GS, Patten R, et al. Leguminous seeds in the dietary management of hyperlipidemia. Am J Clin Nutr. 1983;38:567-573.

Jimenez-Cruz A, Turnbull WH, Bacardi-Gascon M, Rosales-Garay P. A high-fiber, moderate-glycemic-index, Mexican style diet improves dyslipidemia in individuals with type 2 diabetes. Nutr Res. 2004;24(1):19-27.

Kabagambe EK, Baylin A, Ruiz-Narvarez E, Siles X, Campos H. Decreased consumption of dried mature beans is positively associated with urbanization and nonfatal acute myocardial infarction. J Nutr. 2005;135(7):1770-1775.

Moore TJ, Vollmer WM, Appel LJ, Sacks FM, Svetkey LP, Vogt TM, Conlin PR, Simons-Morton DG, Carter-Edwards L, Harsha DW. Effect of dietary patterns on ambulatory blood pressure: reulsts from the Dietary Approachs to Stop Hypertention (DASH) Trial: DASH Collaborative Research Group. Hypertension. 1999 Sep;34(3):472-7.

National Heart, Lung, and BloodInstitute (2005). Your Guide to Lowering Your Cholesterol With TLC (NIH Publication No. 06-5235).

Shutler SM, Bircher GM, Tredger JA, Morgan LM, Walker AF, Low AG. The effect of daily baked bean (Phaseolus vulgaris) consumption on the plasma lipid levels of young, normo-cholesterolemic men. Br J Nutr. 1989;61:257-265.

Simpson HCR, Lousley S, Geekie M, et al. A high-carbohydrate leguminous fiber diet improves all aspects of diabetic control. Lancet. 1981;1(8210):1-4.

Van Horn L, McCoin M, Kris-Etherton PM, Burke F, Carson JS, Champagne CM, et al. The evidence for dietary prevention and treatment of cardiovascular disease. J Am Diet Assoc. 2008;108:287-331.

Winham DM, Hutchins AM. Baked bean consumption reduces total cholesterol in mildly hypercholesterolemic men and women. Nutr Res. 2007;27:380-386.

Winham DM, Hutchins AM, Johnston CJ. Pinto bean consumption reduces biomarkers for heart disease risk. J Am Coll Nutr. 2007;26(3):243-249.