Kinetics of omega-3 polyunsaturated fatty acids when co-administered with saturated or omega-6 fats

Absorption of long chain omega-3 polyunsaturated fatty acids (LCn-3PUFA) has been shown to be potentiated when consumed with a high fat meal. However, the effect of different dietary fats on n-3PUFA absorption and postprandial kinetics has not been previously studied.

In a randomized cross-over design intervention, postprandial incorporation of LCn-3PUFA into plasma lipids following consumption of a meal rich in either saturated fat or omega-6 polyunsaturated fatty acids (n-6PUFA) was investigated. Healthy adult male and female subjects (n=26) were fed an isocaloric meal containing equivalent amount of either butter or sunflower seed oil supplemented with 1.8grams of LCn-3PUFA (300mg eicosapentaenoic acid, 20:5n-3 and 1500mg docosahexaenoic acid, 22:6n-3).

Postprandial plasma lipids were enriched with saturated fatty acids and linoleic acid (18:2n-6) following consumption of the butter and the sunflower oil containing meals respectively. The increase in plasma 20:5n-3 and 22:6n-3 levels over the 6hour study period was similar in both the saturated and the n-6 fat groups.

These results suggest that the expected competition between LCn-3PUFA and n-6PUFA at the absorption level is unlikely; therefore competition at the enzymatic level should be primarily responsible for differences in their metabolic and clinical effects. Trial registered with the Australia New Zealand Trial registry as ACTRN12612000654853.