Food selection based on total antioxidant capacity can modify antioxidant intake, systemic inflammation, and liver function without altering markers of oxidative stress

Abstract

Background: It is unknown whether diets with a high dietary total antioxidant capacity (TAC) can modify oxidative stress, low-grade inflammation, or liver dysfunction, all of which are risk factors for type 2 diabetes and cardiovascular disease. Objective: We studied the effect of high- and low-TAC (HT and LT, respectively) diets on markers of antioxidant status, systemic inflammation, and liver dysfunction. Design: In a crossover intervention, 33 healthy adults (19 men, 14 women) received the HT and LT diets for 2 wk each. Dietary habits were checked with a 3-d food record during both diet periods and the washout period. Results: Fruit and vegetable, macronutrient, dietary fiber, and alcohol intakes did not differ significantly between the 2 diets, whereas dietary TAC, α-tocopherol, and ascorbic acid were significantly (P < 0.001) higher during the HT diet. Plasma α-tocopherol rose during the HT and decreased during the LT diet (P < 0.02 for difference) without changes in markers of oxidative stress except plasma malondialdehyde, which decreased unexpectedly during the LT diet (P < 0.05). Plasma high-sensitivity C-reactive protein, alanine aminotransferase, gamma-glutamyltranspeptidase, and alkaline phosphatase concentrations decreased during the HT compared with the LT diet (mean ± SEM for pre-post changes: -0.72 ± 0.37 compared with 1.05 ± 0.60 mg/L, P < 0.01; -1.73 ± 1.02 compared with 2.33 ± 2.58 U/L, P < 0.01; -2.12 ± 1.45 compared with 5.15 ± 2.98 U/L, P < 0.05; and 1.36 ± 1.34 compared with 5.06 ± 2.00 U/L, P < 0.01, respectively). Conclusion: Selecting foods according to their TAC markedly affects antioxidant intake and modulates hepatic contribution to systemic inflammation without affecting traditional markers of antioxidant status. © 2008 American Society for Nutrition.