Up Close and Edible: Peanut Butter

Researchers are going nuts for peanut butter. Once reviled as a fat-laden, food no-no, it turns out that the creamy (or crunchy) comfort food can actually reduce your risk of heart disease and diabetes and even keep you from gaining weight.

Peanut butter contains about 90 percent peanuts. And that lowly legume is packed with vitamins A and E, folic acid, calcium, magnesium, zinc, iron and fiber. And though peanut butter is loaded with fat, it's monounsaturated, the so-called "good fat" that doesn't raise blood cholesterol levels. Better yet, contrary to what you may think, peanut butter—even commercial varieties—is virtually trans-fat free, according to the U.S. Department of Agriculture. "When it comes to healthy eating, peanut butter rocks," says Dave Grotto, a spokesperson for the American Dietetic Association.

All that good news should be enough to lure back any peanut butter defectors who were scared off in February, when a salmonella outbreak was reported in two brands of the treat—Peter Pan and Great Value. (The recalled jars have a product code on the lid that begins with the number 2111.) But if you're still looking for an excuse to revisit this childhood fave, there are also some encouraging new studies. At Penn State University, researchers compared a low-fat diet to one that was higher in monounsaturated fat from peanuts and peanut butter. They found that both diets will lower total and LDL-cholesterol (the bad cholesterol) levels. But the peanut and peanut-butter diet had the added benefit of lowering triglyceride levels. High triglycerides are linked with heart disease. Overall, the low-fat dieters lowered cardiovascular disease risk by only 12 percent, while the peanut and peanut-butter dieters lowered their risk by 21 percent.

Researchers at Harvard University's School of Public Health found that eating a half serving (one tablespoon) of peanut butter or a full serving of peanuts or other nuts (an ounce), five or more times a week, lowers the risk of developing type-2 diabetes by as much as 20 to 30 percent. "Peanut butter got a bad rap when everyone was on a low-fat kick," says lead researcher Dr. Frank Hu, associate professor of nutrition and epidemiology. "But the body of evidence is overwhelming that peanuts and nut butters can reduce the risk of serious disease."

And it seems to be good for your waistline, too. Penn State researchers found that peanut eaters had lower body mass indexes (BMIs), compared to non-peanut eaters. The higher your BMI (25 and lower is considered optimal), the greater your risk of obesity-related problems like heart disease or diabetes.

But don't fall prey to eating too much of a good thing. Peanut butter is high in calories. A single serving, or two tablespoons of low-fat or regular peanut butter, has about 190 calories. "The point is not to go through the whole jar in one sitting," says Dr. Penny Kris-Etherton, distinguished professor of nutrition at Penn State. She recommends peanut butter as a snack alternative or as a meal, such as a PB&J on whole-wheat bread. Good news for those of us who like our foods comfortable and sticky.