Incorporation of cis-9, trans-11 or trans-10, cis-12 conjugated linoleic acid into human erythrocytes in vivo

The purpose of this study was to determine the incorporation into erythrocytes of cis (c)-9,trans (t)-11 conjugated linoleic acid (CLA) and t10,c12 CLA consumed as supplements highly enriched in these isomers. Healthy men (31 ± 8 years) consumed 1, 2, and 4 capsules containing approximately 80 g/100 g of either c9,t11 CLA or t10,c12 CLA for sequential 8-week periods. Fatty acid concentrations in erythrocyte total lipids were determined at baseline and after consumption of the highest dose. The increase in c9,t11 CLA concentration (0.31 g/100 g) was significantly greater than that in t10,c12 CLA (0.19 g/100 g). This was associated with minor changes in concentrations of some fatty acids of chain length greater than 20 carbons. These data suggest selective assimilation of individual CLA isomers into erythrocyte lipids and partial substitution for specific saturated and polyunsaturated fatty acids.