USDA Study Shows Trans-Fatty Acid is Non-Detectable in Peanut Butter

May 1, 2001

According to a new study by the United States Department of Agriculture/Agricultural Research Service (USDA/ARS), both natural and commercial brands of peanut butter contain no detectable trans-fatty acids. The study, “Non-detectable Levels of transFatty Acids in Peanut Butter,” is published in the May 2001 issue of the Journal of Agricultural and Food Chemistry.

The study examined the fatty acid content of eleven different brands of peanut butter, including Skippy, Jif, Peter Pan and Smuckers, and found no trans-fat in any of the samples. Some peanut butters contain a small amount (approximately 1-2 percent) of partially hydrogenated oil used as stabilizers to prevent oil separation. This produces a smooth and creamy product that most consumers prefer. The amount of trans-fat in peanut butter with 2% stabilizer is less than .0032 g, or 156 times less than what is needed to reach the 0 g trans-fat cut-off.

The study concludes, “Consumption of these products (peanut butter) should, therefore, not be of concern to individuals monitoring trans-fatty acid intake. Natural types and freshly ground peanuts were not found to be different from commercial peanut butters in trans-fatty acid content.” Tim Sanders, PhD, research leader of USDA/ARS, Market Quality and Handling Research Unit located at North Carolina State University, says, “Consumers worried about trans-fats in their diet need not avoid commercial peanut butters.”

Much of the confusion about trans-fatty acid in peanut butters occurs because of the way peanut butter is labeled. Most peanut butters contain only three or four ingredients. By law, peanut butter must consist of at least 90% peanuts. In addition, a minimum amount of salt and sugar is usually added for taste, plus about 1-2% stabilizer to improve texture and increase shelf-life.

A trans-fatty acid results when hydrogen is added to unsaturated vegetable oils. This increases shelf life and improves the texture of food products. The hydrogen is added and crosses (trans) the chemical chain, making the fat more solid at room temperature. Trans fats are found in foods like cookies, crackers, baked goods and fried foods. They are also naturally occurring in small amounts in meat and dairy products. Trans fats tend to increase total and LDL cholesterol, and also may decrease HDL (good) cholesterol. Over 80% of the fat in peanut butter is the cholesterol-lowering, good unsaturated kind, and, as with all plant foods, peanut butter contains no cholesterol. Researchers at Penn State University found that moderate-fat diets with peanuts and peanut butter lowered blood cholesterol levels and was more effective than a low-fat diet in maintaining levels of good HDL-cholesterol and lowering triglyceride levels. As one of America’s favorite foods, we eat more than 800 million pounds of peanut butter each year. Peanut butter was invented around 1890 as a health food for undernourished patients. To this day, peanut butter provides an inexpensive source of plant protein, healthy monounsaturated fats, and an abundance of nutrients like folate, niacin, copper, selenium, zinc, magnesium, and fiber. Peanut products also contain significant amounts of phytosterols thought to protect against heart disease and cancer. The article can be found in the Journal of Agricultural and Food Chemistry, (Volume 49, Number 5, pages 2349-2351) Oil Chemists Society.

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