Effects of Peanut Consumption on Hunger, Ingestive Behavior, Energy Expenditure, and Coronary Heart Disease Risk (PUR 10)
The goal of PUR 10 was to determine the health effects of peanut consumption. The results hold implications for individuals with marginal nutritional status and individuals with concerns about over-nutrition. The indices studied are the effects of peanut consumption on appetitive sensations, food choice, energy balance, and cardiovascular disease (CVD) risk.
Research is underway in the U.S., Ghana, and Brazil to confirm preliminary research that approximately 17% of the energy from whole peanuts was lost in the stool, with 7% lost in peanut butter, and 4.5% in peanut oil. If this data is confirmed, peanuts may be included in the diet with little impact on body weight, and further supports the conclusion and FDA claim that peanut consumption is associated with reduced cardiovascular disease risk. Research on the consumption of oils did not show effect on appetitive responses, but whole peanuts tended to satisfy the appetite which suggests that other fractions of the nuts other than lipids are responsible. In the U.S., HDL-cholesterol/LDL-cholesterol ratios changed in a favorable direction, i.e., towards lower cardiovascular disease risk. In addition no significant weight gain was observed, that was consistent with findings from whole peanuts and supported the recommendations that peanuts may be a healthful component of the diet. In Brazil, the data suggest that peanut oil had no effect on the cholesterol components and did promote weight gains Additional findings with peanut oil show that this nutrient does not hold stronger satiety properties than other oils rich in monounsaturated or polyunsaturated fatty acids; while significant dietary compensation (45-50% of energy) was observed, daily energy and fat intake were significantly increased with addition of oils to the diet; no differences were observed between countries. In another study, the effects of chronic peanut consumption on diet composition as well as serum lipid, magnesium and homocysteine concentrations in free-living subjects were examined. The results showed that regular peanut consumption lowers serum triacylglycerol, augments consumption of nutrients (tocopherol, copper, arginine, and fiber) associated with reduced CVD risk and increases serum magnesium concentration (risk of CVD increases with low magnesium content); i.e., regular peanut consumption can lead to dietary and biochemical changes associated with reduced CVD risk. New studies are comparing peanut consumption patterns, “with meals” specifically lunch, versus “as snacks,” relative to optimal uptake pattern(s) and energy balance. In the peanut meal treatment, hunger during the 2-hour post-lunch interval was suppressed, which suggests peanuts can reduce overall snacking. Snacking prevalence in the U.S.A. adult population has risen 77% to 84% from 1977 to 1996. Mid-afternoon is a common snacking time, therefore including peanut snacks (which have been related to a lower Body Mass Index) in the diet may reduce subjective ratings of hunger and in time reduce Body Mass Index.
Dr. Richard Mattes
Dr. Phoebe Lokko, Food Research Institute, Accra
Dr. Josephina Bressan, Federal University of Viscosa