Oxidized Lipid and its Association with Markers of Adiposity NHANES-2005-06

Background: Polyunsaturated fatty acids (PUFA) are found in nuts and seeds, salad dressings and vegetable oil and are prone to oxidation during storage and food preparation. Evidence supports that consumption of oxidized lipids promotes atherosclerosis and glucose intolerance in animal models. However there is a dearth of evidence with regard to the amount of oxidized lipids consumed and its association with parameters of adiposity and glucose homeostasis in humans. Objective: The objective of this study is to estimate the amount of oxidized lipids in common foods and the oxidized lipid consumption in the US population using the data from National Health and Nutrition Examination Survey (NHANES) 2005-06. The second objective of this study is to investigate if there is an association between consumption of oxidized lipids with markers of adiposity and glucose tolerance. MethodsFoods with possible high oxidized lipid content were selected from the NHANES food frequency questionnaire. Oxidized lipid content /Peroxide Values (PV) of these foods were determined from published values in the literature. Oxidized lipid consumption was stratified into tertiles to determine the relationship between consumption of oxidized lipids and markers of adiposity. Regression analysis was used to explore to the extent to which body fat % and HOMAIR scores could be attributed to oxidized lipid intake. ResultsThe estimated mean daily consumption of oxidized lipids was 0.625 meq/kg of fat for the US population. Estimated mean consumption of oxidized lipids was significantly greater in men compared to women, in children compared to adults and among African Americans compared to other races. In both men and women it was observed that the markers of adiposity like body fat%, waist circumference, triceps skinfold decreased significantly with increased consumption of oxidized lipids. However in women (below 18 years) there was a significant increase in HOMA-IR with increased consumption of oxidized lipids. ConclusionIncreased consumption of oxidized lipids is associated with decreased fat mass but increased glucose intolerance in women, but not in men. Consumption of Oxidized lipid and its Association with Markers of Adiposity NHANES-2005-06 By Payal Arora A Thesis Submitted to the Graduate Faculty of Georgia State University in Partial Fulfillment of Requirements for the Degree of Master of Science in Health Sciences College of Health and Human Sciences Division of Nutrition Georgia State University Atlanta, Georgia 2011