Dietary fat manipulation has a greater impact on postprandial lipid metabolism than the apolipoprotein E (epsilon) genotype–insights from the SAT genε study

Scope Our aim was to determine the effects of chronic dietary fat manipulation on postprandial lipaemia according to apolipoprotein ( APO ) E genotype. Methods and results Men (mean age 53 ( SD 9) years), prospectively recruited for the APOE genotype ( n = 12 E 3/ E 3, n = 11 E 3/ E 4 ), were assigned to a low fat ( LF ), high fat, high‐saturated fat ( HSF ), and HSF diet with 3.45 g/day docosahexaenoic acid ( HSF ‐ DHA ), each for an 8‐week period in the same order. At the end of each dietary period, a postprandial assessment was performed using a test meal with a macronutrient profile representative of that dietary intervention. A variable postprandial plasma triacylglycerol ( TAG ) response according to APOE genotype was evident, with a greater sensitivity to the TAG ‐lowering effects of DHA in APOE 4 carriers ( p ≤ 0.005). There was a lack of an independent genotype effect on any of the lipid measures. In the groups combined, dietary fat manipulation had a significant impact on lipids in plasma and Svedberg flotation rate ( S f ) 60–400 TAG ‐rich lipoprotein fraction, with lower responses following the HSF ‐ DHA than HSF intervention ( p < 0.05). Conclusion Although a modest impact of APOE genotype was observed on the plasma TAG profile, dietary fat manipulation emerged as a greater modulator of the postprandial lipid response in normolipidaemic men.