Protein, Good Fats in Peanuts Reduce Blood Pressure and Heart Disease

Nov 17, 2005

The OmniHeart Study (Optimal Macronutrient Intake Trial for Heart Health), which tested optimal diet patterns, was released in the latest issue of the Journal of the American Medical Association. OmniHeart was conducted at two major medical centers, Johns Hopkins Medical Institution in Baltimore, MD and Brigham and Women’s Hospital in Boston, MA. It compared three diet patterns; the first diet was based on the Dietary Approaches to Stop Hypertension (DASH) diet and emphasized carbohydrates; the second diet had higher protein levels, particularly from plant sources; and the third had a higher fat level from good unsaturated fats.

In the OmniHeart Study, peanuts and peanut butter were part of all three diets, but contributed most to the optimal diet higher in plant protein, which came out with the top score. In the higher protein diet, over half of the protein came from increases in plant sources. Nutritionist Janis Swain, MS, RD, at the Brigham and Women’s Hospital said, “Peanuts and peanut butter made an important contribution to the overall increase in plant protein in the higher protein diet.” Approximately 4 ounces of peanuts/peanut butter were consumed by the study participants on the higher protein diet per week.

The DASH diet is one of the best-studied diet patterns and was included in the 2005 U.S. Dietary Guidelines as an excellent eating model. However, the two modified diet patterns in this study actually turned out to be an improvement over the DASH diet. Lead investigator, Frank Sacks, M.D., at Brigham and Women’s Hospital, Harvard Medical School, said, “all three diets are good; it’s just that the higher protein and unsaturated fat diets are somewhat better.” All diets reduced blood pressure and coronary heart disease risk. The higher protein diet also decreased “bad” LDL cholesterol and triglycerides, while the diet with good unsaturated fat increased “good” HDL cholesterol and lowered triglycerides. The diet estimated 10-year coronary heart disease risk was lowered on both of these diets, compared to the one with higher carbohydrates, thus they scored better.

Peanuts and peanut butter are tasty and convenient sources of plant protein. Technically, peanuts are legumes and have high protein content that is comparable or better to a serving of beans. In addition, peanuts have the highest protein content of any nut. Furthermore, peanuts, peanut butter, and peanut oil are excellent sources of good monounsaturated fats that were used in the third diet pattern (high in good unsaturated fat) and can thus be excellent heart-healthy choices in both of the optimal diets.

Consumption of peanuts and peanut butter represents over two thirds of nut consumption in the United States. They are among America’s favorite “comfort” foods and are ideal as a food or snack to be included every day or in a variety of meals. For example, peanuts can be sprinkled on salads or cereals and peanut butter can be spread on a bagel or whole grain bread instead of butter.

Previous studies have shown that a small amount of peanut consumption per day, about 1 to 1 1/2 ounces, reduces the risk of heart disease and diabetes. The protein and fiber in peanuts improves satiety and maintains weight loss. Including peanuts in the diet also makes it easier to achieve important nutrient goals set by the U.S. government in the U.S. Dietary Guidelines. Incorporating peanuts in the diet improved the status of hard-to-get nutrients such as vitamin E, folate, magnesium, zinc, iron, and dietary fiber.

The OmniHeart Study was supported by the National Heart, Lung, and Blood Institute of the National Institutes of Health.

The Peanut Institute is a non-profit organization that supports nutrition research and develops educational programs to encourage healthful lifestyles.