Peanuts are often thought of as high-fat foods; however, not only do peanuts contain the so-called "good" kind of fat, University of Florida (UF) researchers have found they also are high in a wide variety of helpful antioxidants, rivaling the fruits often sought out by health-conscious consumers.
"When it comes to antioxidant content, peanuts are right up there with strawberries," said Steve Talcott, an assistant professor of food science and human nutrition at UF's Institute of Food and Agricultural Sciences. "We expected a fairly high antioxidant content in peanuts, but we were a bit shocked to find that they're as rich in antioxidants as many kinds of fruit."
Talcott and other UF researchers tested the antioxidant content of a dozen peanut varieties in a study published recently in an issue of the journal Food Chemistry.
Antioxidants are chemicals that block the aging effects of free radicals -- unstable molecules naturally occurring in the human body that damage living cells. The damage caused by free radicals has been linked to heart disease, stroke, certain cancers and macular degeneration.
The growing reputation of antioxidants has led an increasing number of people to include more fruits in their diets, particularly those that are orange or red in color, because such foods have been found to be rich in the health-promoting chemicals. Vitamins A, C and E are recognized as antioxidants, and polyphenols -- a family of chemicals commonly found in foods -- also have strong antioxidant properties. Peanuts are a good source of vitamin E, but in the past, they typically have not been considered an antioxidant-rich food, largely because of a lack of data on their polyphenol content.
Now, UF researchers have found that peanuts contain high concentrations of polyphenols -- chiefly a compound called p-coumaric acid. In addition, they found that roasting can increase the level of p-coumaric acid in peanuts, boosting their overall antioxidant content by as much as 22%.
"If you compare them to other foods people think of as rich in antioxidants -- mostly fruits and berries -- peanuts come out somewhere in the middle," Talcott said. "They're no match for the foods at the top of the scale, such as pomegranate, but they do rival other foods that people eat just for their antioxidant content."
Talcott said roasted peanuts are about as rich in antioxidants as blackberries or strawberries, and are far richer in the chemicals than fruits such as apples, carrots or beets.
The findings add to the growing reputation peanuts are getting for their healthy benefits.
"We already know from previous studies that including peanuts and peanut butter in a healthful diet can lower cholesterol, help people lose weight and prevent type 2 diabetes," said Kristen Ciuba, a nutritionist for the Peanut Institute, a nonprofit organization in Albany, Georgia, funded by the peanut industry.