Evaluation of the postprandial effects of a fast-food meal on human plasma F2-isoprostane levels

Measurement of the F2-isoprostane, 8-epi-PGF2α is increasingly used as a sensitive and reliable marker of lipid peroxidation in vivo. Because the majority of 8-epi-PGF2α in plasma is associated with lipoproteins, it is possible that 8-epi-PGF2α 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-PGF2α in nine healthy subjects. Blood was collected before and 2 h postprandially. 8-Epi-PGF2α was measured by immunoaffinity extraction and gas chromatography–mass spectrometry. Fasting plasma 8-epi-PGF2α (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 not 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-PGF2α and other lipid peroxidation markers was small.