Effect of increased vegetable and fruit consumption on markers of oxidative cellular damage

The goal of this study was to test the hypothesis that increased consumptio n of vegetables and fruit would reduce markers of oxidative cellular damage that can be assessed in blood or urine, Twenty-eight women participated in a 14 day dietary intervention. The primary end-points assessed were: 8-hyd roxydeoxyguanosine (8-OHdG) in DNA isolated from peripheral lymphocytes, de termined by HPLC with electrochemical detection; 8-OHdG excreted in urine, measured by ELISA; malondialdehyde (MDA) in urine, measured by fluorimetric detection following derivatization with thiobarituric acid and separation via HPLC; urinary 8-isoprostane F-2 alpha (8-EPG) detected by ELISA. Pre- a nd post-intervention plasma levels of selected carotenoids were determined by HPLC. Subjects were free living and consumed a completely defined recipe -based diet that increased their average daily consumption of vegetables an d fruit from 5.8 servings at baseline to 12.0 servings throughout the inter vention. Overall, the level of 8-OBdG in DNA isolated from lymphocytes and in urine and the level of 8-EPG in urine were reduced by the intervention, whereas urine concentrations of MDA were minimally affected. The reduction in lymphocyte 8-OHdG was greater in magnitude (32 versus 5%) in individuals with lower average preintervention levels of plasma a-carotene (56 ng/ml) than in individuals with higher average pre-intervention plasma levels of a lpha-carotene (148 ng/ml), The results of this study indicate that consumpt ion of a diet that significantly increased vegetable and fruit intake from a diverse number of botanical families resulted in significant reductions i n markers of oxidative cellular damage to DNA and lipids.