Food habits are associated with lipid peroxidation in an elderly population

Objective The purpose of this study was to assess the association between dietary intake and lipid peroxidation.Design Cross-sectional population analysis from an ongoing prospective study. Malondialdehyde (MDA) was measured as a marker of lipid peroxidation. Diet was assessed through direct observation and food frequency questionnaire.Subjects Participants with no missing data were 162 nonsmoking elderly individuals residing in 7 institutions across Asturias (Spain).Statistical analyses performed Comparisons of adjusted group means by tertiles of plasma MDA were made by analysis of variance. Stepwise regression analysis was done using MDA as a dependent variable and food intake as an independent variable. Food intakes were categorized into quartiles and logistic regression was applied to calculate the odds ratio for being in the highest tertile of plasma MDA.Results Consumption of potatoes had an independent direct effect and accounted for a sizeable proportion of the variation in plasma MDA levels (18%, P<.001). In addition to potatoes, other foods that had an apparently independent effect on plasma MDA were eggs, cooked vegetables, and red wine (R-2=0.028, 0.023 and 0.018, respectively). In this study, dietary factors accounted for 25% of the variation in plasma MDA levels.Conclusion Identifying nutritional determinants of oxidative stress is important because of its negative health effect. Consumption of cooked vegetables and moderate intake of wine has been shown to be appropriate for reducing the risk of oxidative damage. On the contrary, caution must be used with the intake of potatoes because we have found a positive association with MDA levels. Further studies are required to investigate the mechanism(s) of this association and whether it is related to the preparation method or to the potato itself.