The US Food and Drug Administration (FDA) has affirmed a qualified health claim that peanuts and some other nuts may reduce the risk of heart disease when consumed regularly. This action, according to the Peanut Institute, 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 five or more times a week.
Some labels will soon carry the government-approved message, "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. 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.
The principal investigator, Penny Kris-Etherton, PhD, RD, says, "the overall results of our study show that diets that include peanuts and peanut butter daily reduce the risk of heart disease by 21% as compared to the average American diet, whereas a low-fat diet reduces the risk by only 12% compared to the average American diet."
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. Data from Harvard School of Public Health's Nurses' Health Study has shown that substituting peanuts and nuts for saturated fat or refined carbohydrates can reduce risk of heart disease by 45% and 30%, respectively.
A growing database of clinical studies indicates that part of the beneficial effect of peanuts and nuts may not only be due to their fatty acid composition, but other key nutrients, particularly when they replace less healthful foods in the diet.
Researchers at Purdue University found that subjects who snacked on peanuts self-adjusted their caloric intake spontaneously and did not add extra calories to their daily diets. The fat and protein in peanuts contributes to their high satiety value, making portion-control packs of peanuts an ideal snack for dieters.
Researchers at Harvard School of Public Health found that dieters who included a moderate amount of good fat in their diets from foods like peanuts, nuts and unsaturated oils, were able to lose more weight and keep it off over the long term.
The recommended daily dose to help your heart is a small handful of most nuts, which is about 60 peanuts. Manufacturers have moved quickly to provide consumers with small, portion-control packets, such as the Planters one-ounce on-the-go packets and single serve tubes of peanuts that can now be found in grocery stores, airports and vending machines.
Pat Kearney, MEd, RD, senior nutritionist for The Peanut Institute, notes that this health claim follows recent dietary advice to eat good unsaturated fats in place of saturated fat and refined carbohydrates. Kearney says, "This health claim should guide consumers to make more healthful food choices. Small dietary changes can lead to big rewards when it comes to health. Snack on peanuts in the afternoon to satisfy hunger, or sprinkle nuts on salads instead of croutons or cheese."
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% 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. 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.
Like all plant foods, peanuts and nuts are cholesterol-free. Peanuts also contain bioactive components such as resveratrol (the substance also found in red wine), beta sitosterol, flavonoids, and antioxidants, the benefits of which nutrition scientists are only beginning to discover.
Over half of the "nuts" eaten in the United States each year are peanuts. Recent US Department of Agriculture data shows that 68% of the "nuts" eaten 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.