The US Food and Drug Administration (FDA) affirmed a health claim that peanuts and other nuts may reduce the risk of heart disease when consumed daily in small amounts. This action is based on a large body of epidemiological and clinical studies showing a 25-50% reduction in the risk of heart disease when 1 to 2 ounces of peanuts or nuts are consumed 5 or more times a week.
The approved claim says “Scientific evidence suggests but does not prove that eating 1.5 ounces of most nuts, such as peanuts, as part of a diet low in saturated fat and cholesterol may reduce the risk of heart disease. See nutrition information for fat content.” One of the strongest studies presented to FDA was a six-month controlled study done at Pennsylvania State University, which showed that diets that included peanuts and peanut butter daily reduced the risk of heart disease by 21% as compared to the average American diet and by 12% compared to a low-fat diet. Subjects following the “peanut diet” lowered total cholesterol by 11% and the bad LDL cholesterol by 14%. Triglycerides were also lowered but the good HDL cholesterol was maintained. (1) Americans consume an average of six pounds of peanuts and peanut butter per person each year. Recent US Department of Agriculture data shows that 68% of the “nuts” eaten in the United States are split evenly between peanuts and peanut butter, about 6% are almonds, 6% are coconuts, 5% are pecans, 5% are walnuts, and 10% are all other nuts combined. (2) This data is consistent with an earlier study by Harvard researchers that shows that about half of the nuts eaten by women in the Nurses’ Health Study were peanuts. (3)
Data from The Nurses’ Study has shown that substituting peanuts and nuts for saturated fat can reduce risk of heart disease by 45% or 30% when substituted for refined carbohydrate. Other large population studies, such as the Adventists Health Study, the Iowa Women’s Health Study and the Physicians Heath Study, all show a linear relationship between cardioprotective benefits and peanut and nut consumption. (4-6) A growing database of clinical studies indicates that part of the beneficial effect of peanuts and nuts may be due to their fatty acid composition, particularly when they replace food sources of saturated fatty acids, as well as refined carbohydrates, in the diet.
Since peanuts are technically a legume, they have the highest amount of protein of any “nut.” They also are highest in the amino acid arginine, a precursor to nitric oxide, which helps to dilate blood vessels and improve blood flow. Peanuts are also a good way to consume many other beneficial micronutrients in the diet. In addition to containing over 75 percent of the good unsaturated fat, peanuts are a good source of fiber, as well as vitamin E, folate, potassium, magnesium, and zinc, all which are thought to be important to health. Peanuts also contain bioactive components such as resveratrol, beta sitosterol, flavonoids, and antioxidants, the benefits of which nutrition scientists are only beginning to discover. For example, a recent study done at Purdue University showed that subjects with low levels of magnesium in their blood were brought up into normal ranges when they ate peanuts every day.