New research summarized in a supplement to this month’s issue of the Journal of Nutrition talks about the health benefits of peanuts, peanut butter, and nuts. The new articles highlight a consistent body of evidence showing why peanuts contribute to decreasing chronic disease risk, how they improve nutrient quality in the diet and how they are included in the diet without posing a threat to weight gain.
Technically a legume, peanuts are still America’s most popular nut of the 10 main types eaten. Over two-thirds of the nuts eaten are peanuts and peanut butter. New data from the USDA “What We Eat in America” survey of almost 20,000 people shows that the average “intake of specific types of nuts eaten as snacks was led by peanuts.“ Nut consumption was divided into three categories: “eaten as snacks”,” peanut butter”, or as “recipe ingredient.” Over half of the snack nuts are peanuts. Peanut eaters consume about 25.8 grams per day (g/d) versus consumers of mixed nuts, which contain about half peanuts (10.4 g/d), cashews (6.3 g/d), almonds (4.1g/d), pistachios (3.5 g/d), pecans (1.3 g/d), and walnuts (1.1 g/d).
A review of the population studies established peanuts, peanut butter, and other nuts as significantly contributing to prevention of chronic disease. The data shows that “all epidemiologic studies conducted in the U.S. have reported a beneficial relationship” and that “peanut consumption also was associated with lower relative risk of CHD.” Eating about a handful of peanuts or a serving of peanut butter 5 times per week can cut heart disease risk by up to a half. Diabetes risk is also cut by almost a quarter with an ounce serving of peanuts per day or just a half serving (1 tbsp) of peanut butter.
With the obesity epidemic, some may say that nuts should not be included in the diet due to their fat and calorie content. An ounce of peanuts per day, however, has only about 160 calories. Peanuts have healthy fat, which improves cholesterol levels. New evidence also suggests that these healthy fats are “oxidized more readily than saturated fats.”
Furthermore, evidence consistently shows that people who eat peanuts have a lower body mass index (BMI). “Female peanut users had a significantly lower BMI than nonusers and for men, there was a trend for a lower BMI in peanut users.” BMI was also “lower in children (both males and females) who were peanut users relative to nonusers. ”This could be due to many reasons. Research shows that peanuts have had the highest effect of nuts on dietary compensation, which means that people naturally eat less at other times of the day after consuming them. Up to two-thirds of the energy in peanuts may be offset. Peanuts also have more protein than any other nut and have fiber, both of which may contribute to reducing hunger or providing long lasting energy. Higher protein diets may be promising for weight loss because of a thermogenic effect.
Peanut research has also led the way in explaining the area of resting energy expenditure, which is the amount of energy the body needs in a 24-hour period while at rest. In two different studies, the data has shown peanuts to be the only nut with a statistically significant difference in REE. “Peanuts led to an 11% increment in REE over 19 wk. In another trial, peanut consumption for 8 wk was associated with a significant 5% increment in REE but only among obese individuals (the increment was 11% among males).” In addition, it’s estimated that 10-15% of what’s consumed is undigested.
Peanuts bring healthy fats, plant protein, and fiber to the diet, but they also bring hard-to-get nutrients like magnesium, potassium, and vitamin E, as well as bioactive compounds, such as resveratrol, the “anti-aging” molecule, and arginine, a precursor to nitric oxide, which can expand blood vessels.
The published research was summarized by top nutrition scientists that came together to discuss these benefits at the 2007 Nuts and Health Symposium organized and hosted by the US Department of Agriculture Research Service, Western Nutrition Research Center at the University of California, Davis. The Peanut Institute was an organizer of the conference.
The Peanut Institute is a non-profit organization that supports nutrition research and develops educational programs to encourage healthful lifestyles.