Evaluation of the postprandial effects of a fast-food meal on human plasma F-2-isoprostane levels

Measurement of the F-2-isoprostane, 8-epi-PGF(2 alpha) is increasingly used as a sensitive and reliable marker of lipid peroxidation in vivo. Because che majority of 8-epi-PGF(2 alpha) in plasma is associated with lipoproteins, it is possible that 8-epi-PGF(2 alpha) derived from polyunsaturated fatty acid-rich food may become incorporated within these lipoproteins during synthesis and could contribute to the levels detected in plasma. In this study, we evaluated the postprandial effect of a single fast-food meal (McDonald's Big Mac meal, McDonald's Corp., London, England) on plasma total 8-epi-PGF(2 alpha) in nine healthy subjects. Blood was collected before and 2 h postprandially. 8-Epi-PGF(2 alpha) was measured by immunoaffinity extraction and gas chromatography-mass spectrometry. Fasting plasma 8-epi-PGF(2 alpha) (875 +/- 25 pM) increased postprandially (956 +/- 23 pM, p < .05), although no significant change was observed in the normalized concentrations (2.78 +/- 0.1 vs. 2.95 +/- 0.3 nmol/mmol arachidonic acid). Plasma lipid hydroperoxides, fatty acids, vitamin E, total antioxidant status, cholesterol, and triglycerides were nor altered. Plasma glucose increased postmeal (4.4 +/- 0.1 vs. 4.9 +/- 0.1 mM, p < .05). These results indicate that the overall contribution of this lipid-rich meal to plasma 8-epi-PGF(2 alpha), and other lipid peroxidation markers was small. (C) 2000 Elsevier Science Inc.