Heart-Healthy Peanuts Make Top Grades in Weight-Loss Diets

Apr 19, 1999 | News

Researchers at Pennsylvania State University are finding that a weight-loss diet that is high in monounsaturated fat (MUFA) and includes peanuts and peanut butter can not only lower cholesterol levels, but can also help subjects lose weight. These ground-breaking results were announced at the annual Experimental Biology Conference in Washington, D.C.

The study tested two calorically-controlled diets that were low in saturated fat and cholesterol. One of the diets was low-fat (less than 20% calories from fat) and one was higher in total fat (35% of calories from fat, which was mainly monounsaturated). Both groups lost an average of two pounds per week over the six week study period. Both diets lowered total and LDL cholesterol, known risk factors for cardiovascular disease.

The healthy monounsaturated fat was added to Mediterranean-style diets by using peanut butter on bagels and toast instead of butter and jam, snacking on peanuts instead of pretzels, cookies or crackers, using peanut butter in sandwiches instead of lean luncheon meats and using peanutbased dressing with salads and vegetables.

According to Dr. Penny Kris-Etherton, Distinguished Professor of Nutrition at Penn State, “There is now compelling evidence that a high-MUFA ‘Mediterranean-style’ diet is as good as a low-fat diet for weight loss and improving cardiovascular risk factors. This means that healthy diets can include favorite foods, such as peanuts and peanut butter, while promoting weight loss and weight maintenance.”

This study adds to the growing body of evidence linking high-monounsaturated fat diets to heart health. A previous study at Penn State showed that a diet including peanuts, peanut butter, and peanut oil can lower total cholesterol by 10% and LDL (bad) cholesterol by 14% and does not increase triglycerides as occurs with a low-fat diet. The peanut diet reduced heart disease risk factors as effectively as the diet high in olive oil.

Furthermore, the results of a free-living weight-loss study at Harvard Medical School and Brigham and Women’s Hospital in Boston found that after 18 months, almost three times as many subjects on the high-MUFA diet, as compared to the low-fat diet, were still in the study. And, those on the high-MUFA “Mediterranean-style” diet were able to maintain their weight loss of 11 pounds, while those following the low-fat diet gained almost half of the lost weight back. Incorporating more palatable, more satisfying foods into weight loss diets is important for long-term benefits in both losing weight and lowering cholesterol.

Dr. Tom Pearson, Kaiser Professor, Department of Community and Preventive Medicine at the University of Rochester and co-investigator of the study, notes, “The antioxidant vitamin E, folic acid, fiber, and many phytochemicals and hard-to-get minerals may all somehow contribute to peanuts’ heart disease protection.”

The Peanut Institute is a non-profit organization that supports nutrition research and develops educational programs to encourage healthful lifestyles