Evaluation of the postprandial effects of a fast-food meal on human plasmaF-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 lipoprotein s, it is possible that 8-epi-PGF(2 alpha) derived from polyunsaturated fatt y acid-rich food may become incorporated within these lipoproteins during s ynthesis and could contribute to the levels detected in plasma. In this stu dy, we evaluated the postprandial effect of a single fast-food meal (McDona ld'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 extractio n and gas chromatography-mass spectrometry. Fasting plasma 8-epi-PGF(2 alph a) (875 +/- 25 pM) increased postprandially (956 +/- 23 pM, p < .05), altho ugh no significant change was observed in the normalized concentrations (2. 78 +/- 0.1 vs. 2.95 +/- 0.3 nmol/mmol arachidonic acid). Plasma lipid hydro peroxides, fatty acids, vitamin E, total antioxidant status, cholesterol, a nd 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 overal l contribution of this lipid-rich meal to plasma 8-epi-PGF(2 alpha), and ot her lipid peroxidation markers was small. (C) 2000 Elsevier Science Inc.