Effects of fish oil supplementation on apolipoprotein B100 production and lipoprotein metabolism in normolipidaemic males

Objective: To evaluate the effects of four weeks of fish oil supplementation on apolipoprotein B100 production and lipoprotein metabolism in normolipidaemic males. Design and subjects: Very low density lipoprotein (VLDL) apolipoprotein B100 (apoB100) kinetics in ten healthy, white males, aged 22-43 y (mean 32 y) were investigated using a ¹³C-leucine technique and gas chromatography-mass spectrometry before and after fish oil supplementation. Intervention: All subjects received 10 g (1.8 g EPA, 1.2 g DHA)/d of fish oil concentrate for four weeks. Results: Fish oil supplementation resulted in a decrease of total plasma VLDL (mean ± s.d. 1.11 ± 0.41 vs 0.87 ± 0.28 mmol/l, P < 0.05) and triacylglycerol concentrations (0.74 ± 0.27 vs 0.48 ± 0.21 mmol/l, P < 0.01). VLDL apoB100 pool size was decreased without alteration of the fractional synthetic rate but a significant decrease of apoB100 production (2.23 ± 0.90 vs 1.54 ± 0.52 mg/dl/h, P < 0.02). Following fish oil supplementation plasma concentrations of glucose and insulin as well as lipoprotein and hepatic lipase activities were unchanged. Fasting plasma concentrations of non-esterified fatty acid (NEFA) were decreased (0.45 ± 0.12 vs 0.33 ± 0.10 mmol/l, P < 0.05). Conclusions: Dietary supplementation with fish oil in healthy males results in decreased VLDL-triacylglycerol concentrations through a decrease in VLDL particle synthesis. The decrease in NEFA substrate supply also contributes.