Isomerization increases the postprandial oxidation of linoleic acid but not α-linolenic acid in men

Abstract

Human lipid intake contains various amounts of trans fatty acids. Refined vegetable and frying oils, rich in linoleic acid and/or α-linolenic acid, are the main dietary sources of trans-18:2 and trans-18:3 fatty acids. The aim of the present study was to compare the oxidation of linoleic acid, α-linolenic acid, and their major trans isomers in human volunteers. For that purpose, TG, each containing two molecules of [1-13C]linoleic acid, α-[1-13C]linolenic acid, [1-13C]-9cis,12trans-18:2, or [1-13C]-9cis,12cis,15trans-18:3, were synthesized. Eight healthy young men ingested labeled TG mixed with 30 g of olive oil. Total CO2 production and 13CO2 excretion were determined over 48 h. The pattern of oxidation was similar for the four fatty acids, with a peak at 8 h and a return to baseline at 24 h. Cumulative oxidation over 8 h of linoleic acid, 9cis,12trans-18:2, α-linolenic acid, and 9cis,12cis,15trans-18:3 were, respectively, 14.0 ± 4.1%, 24.7 ± 6.7%, 23.6 ± 3.3%, and 23.4 ± 3.7% of the oral load, showing that isomerization increases the postprandial oxidation of linoleic acid but not α-linolenic acid in men.—Bretillon, L., J. M. Chardigny, J. L. Sébédio, J. P. Noël, C. M. Scrimgeour, C. E. Fernie, O. Loreau, P. Gachon, and B. Beaufrère. Isomerization increases the postprandial oxidation of linoleic acid but not α-linolenic acid in men.

Keywords

• human
• oxidation
• trans fatty acid