A pecan-enriched diet increases γ-tocopherol/cholesterol and decreases thiobarbituric acid reactive substances in plasma of adults

Consumption of nuts is associated with a reduced risk of coronary heart disease, and dietary intervention studies incorporating pecans show improved lipid profiles. The unsaturated fats in pecans are protected against oxidation by the high concentrations of gamma-tocopherol and polymeric flavanols. The aim of this study was to determine whether plasma concentrations of tocopherols and measures of antioxidant capacity and of oxidative stress are affected by incorporation of pecans in the diet. In a randomized, controlled, crossover feeding study, 24 subjects were assigned to 2 diets, each for 4 weeks: a control diet and a pecan-enriched (20% of energy) diet. Cholesterol-adjusted plasma gamma-tocopherol increased by 10.1% (P < .001), alpha-tocopherol decreased by 4.6% (P < .001), and malondialdehyde concentrations measured as thiobarbituric acid reactive substances decreased by 7.4% (P < .05) on the pecan diet. No changes were observed for ferric-reducing ability of plasma or Trolox equivalent antioxidant capacity values. These data provide some evidence for potential protective effects of pecan consumption in healthy individuals. (c) 2006 Elsevier Inc. All rights reserved.