Nuts Are a Heart-Healthy Food
November 19, 1998/PRNewswire, New York

Researchers from Harvard University's Nurses' Health Study published results in the recent British Medical Journal showing that women who eat more than 5 oz of nuts a week have a 35% reduction in risk of total coronary heart disease, compared to women who eat only 1 oz of nuts a month or none at all. This study adds to a large and growing body of evidence suggesting that nuts can be an integral part of a heart-healthy diet.

Started in 1976, the Nurses' Health Study regularly collects medical and lifestyle data from close to 120,000 women to help identify risk factors for diseases such as coronary heart disease and cancer. In this current British Medical Journal study, questionnaires were mailed four times between 1980 and 1990 to assess the frequency of nut consumption among female nurses who were free from heart disease and cancer at the start of the study. The subjects' coronary heart disease status was reported from 1980 to mid-1994 and was verified by medical review.

The findings were similar to those from several other large-scale epidemiological studies and from dietary interventions. The Iowa Women's Health Study, another large study of women, reported a 57% reduction in coronary heart disease risk among those consuming two to four servings of nuts weekly. Intervention studies in which heart-healthy diets have been supplemented with relatively large amounts of almonds have shown significant reductions in total blood cholesterol and low-density lipoprotein cholesterol ( the so-called "bad cholesterol") levels but preservation of high-density cholesterol (the so-called "good cholesterol") levels.

Although the exact mechanism behind the protective effects of nuts is not known, there are several possibilities. First, most commonly consumed nuts have a heart-healthy fat profile. They are a good source of unsaturated fats, including monounsaturated and polyunsaturated, and contain little saturated fat. Moreover, as a plant-based food, they contain absolutely no cholesterol. Second, most nuts are rich sources of the amino acid arginine, a precursor of nitric oxide. Nitric oxide helps increase blood flow to the heart and helps inhibit blood clotting. Third, nuts contain significant amounts of magnesium, vitamin E, fiber, potassium, and alpha-linoleic acid, all of which are beneficial to coronary health.

Source: Harvard School of Public Health