Omega-3 Fatty Acid Supplementation and Exercise Training Attenuate Postprandial Lipemia in Sedentary Individuals

Abstract

Omega-3 fatty acid (n-3fa) supplementation and exercise training each can attenuate postprandial lipemia (PPL), but the combination effect is not clear in sedentary individuals. PURPOSE: We examined the effects of four weeks of n-3fa supplementation alone or in combination with aerobic training on the PPL response and high density lipoprotein cholesterol (HDL-C) in previously sedentary individuals. METHODS: Previously sedentary subjects (N=20, 12 women, 8 men, mean age 33y, mean BMI 26 kg/m2) were randomly assigned to one of two treatment groups: n-3fa supplementation alone (FO, n=10) or n-3fa supplementation plus exercise training (FO + ExTr, n=10). Both groups consumed 4 g/d n-3fa, while exercise training consisted of 45 min/d, 5d/wk of walking and/or treadmill jogging at 60% VO2max. Before treatment subjects performed a baseline PPL (Pre-PPL) and an acute exercise PPL (Pre-ExPPL), after a 24h controlled diet including a 12h fast overnight. In Ex-PPL, an acute exercise session at 60% VO2max for 60 min was performed 12h prior to the PPL. Subjects were administered a high fat meal (standardized high fat shake, 1.3 g fat/kg), and blood samples were collected pre, 2h, 4h, 6h, and 8h after the high fat meal for triglyceride (TG) analyses. After treatment, the two PPL trials (Post-PPL and Post- ExPPL) were repeated. PPL response was quantified as total area under the TG curve (TG-AUCTol) and TG peak response. HDL-C and subfractions were analyzed in pre high fat meal samples. RESULTS: Acute exercise did not attenuate the PPL response. Together treatments significantly attenuated the PPL response measured as total TG-AUCTol; FO: Pre-PPL 1121.7 ± 84.1 mg/dl *; 8hr (means ± SE), and Post-PPL 1021.2 ± 57.7; FO + ExTr: Pre-PPL 1580.5 ± 184.3, and Post-PPL 1168.1 ± 115.0. There was no significant main effect for group or group by week interaction. Both groups had higher HDL-C and HDL2-C after treatment than before treatment. CONCLUSION: N-3fa supplementation or the combination of n-3fa with aerobic exercise training attenuates the PPL response and improves HDL-C in previously sedentary people. Combination treatment neither magnifies nor attenuates the effect of n-3fa alone on postprandial lipemia. Supported by Food for the 21st Century, MU HES Margaret Mangel Grant, and NIH T32 AR48523.