High-fat meals rich in EPA plus DHA compared with DHA only have differential effects on postprandial lipemia and plasma 8-isoprostane F2α concentrations relative to a control high–oleic acid meal: a randomized controlled trial

The American Journal of Clinical Nutrition

Aug 2014

DOI: 10.3945/ajcn.114.091223

Citations:30

Influential Citations:2

Interventional (Human) Studies

Enhanced Details

Methods

Randomized, controlled, double-blind crossover trial at King’s College London; 16 nonsmoking men aged 35–70 years with fasting triglycerides >1.2 mmol/L; completed four test-meal visits separated by at least one week.

Intervention

Four isoenergetic high-fat meals (4.6 MJ) with different fat/oil compositions: HOS (high-oleic sunflower oil, control); FO (HOS + fish oil delivering 5 g EPA+DHA); AO (HOS + algal oil delivering 5 g DHA); HLS (high-linoleic acid sunflower oil). FO provided 5 g EPA+DHA; AO provided 5 g DHA. Meals were served as a muffin plus strawberry-flavored milkshake; administered on four separate study visits at least one week apart.

Results

Postprandial triglyceride rise was modestly reduced after FO and HLS versus control; AO did not differ from control. NEFA decreased after all meals, but AO attenuated this decrease (1–3 h). 8-isoprostane F2a rose after FO but fell after AO versus control; no differences in NOx. No consistent differences in vascular function (AIx, DVP measures) or NO metabolites across meals. Conclusion: EPA+DHA-rich fish oil and DHA-rich algal oil have different acute effects on postprandial oxidative stress, but these differences did not translate into consistent improvements in postprandial lipemia or vascular function. More research is needed to understand DHA- vs EPA-derived lipid mediators and their cardiovascular relevance.

Limitations

Male-only sample; small study size with 16 participants and missing Arteriograph24 data in 2 participants, limiting power for vascular endpoints; no pure EPA vs pure DHA comparison available; results reflect acute postprandial responses and may not generalize to long-term effects or women.

Abstract

Background: Eicosapentaenoic acid (EPA) plus docosahexaenoic acid (DHA) supplementation has beneficial cardiovascular effects, but postprandial influences of these individual fatty acids are unclear. Objectives: The primary objective was to determine the vascular effects of EPA + DHA compared with DHA only during postprandial lipemia relative to control high–oleic acid meals; the secondary objective was to characterize the effects of linoleic acid–enriched high-fat meals relative to the control meal. Design: We conducted a randomized, controlled, double-blind crossover trial of 4 high-fat (75-g) meals containing 1) high–oleic acid sunflower oil (HOS; control), 2) HOS + fish oil (FO; 5 g EPA and DHA), 3) HOS + algal oil (AO; 5 g DHA), and 4) high–linoleic acid sunflower oil (HLS) in 16 healthy men (aged 35–70 y) with higher than optimal fasting triacylglycerol concentrations (mean ± SD triacylglycerol, 1.9 ± 0.5 mmol/L). Results: Elevations in triacylglycerol concentration relative to baseline were slightly reduced after FO and HLS compared with the HOS control (P < 0.05). The characteristic decrease from baseline in plasma nonesterified fatty acids after a mixed meal was inhibited after AO (Δ 0–3 h, P < 0.05). HLS increased the augmentation index compared with the other test meals (P < 0.05), although the digital volume pulse–reflection index was not significantly different. Plasma 8-isoprostane F2α analysis revealed opposing effects of FO (increased) and AO (reduced) compared with the control (P < 0.05). No differences in nitric oxide metabolites were observed. Conclusions: These data show differential postprandial 8-isoprostane F2α responses to high-fat meals containing EPA + DHA–rich fish oil compared with DHA-rich AO, but these differences were not associated with consistent effects on postprandial vascular function or lipemia. More detailed analyses of polyunsaturated fatty acid–derived lipid mediators are required to determine possible divergent functional effects of single meals rich in either DHA or EPA. This trial was registered at clinicaltrials.gov as NCT01618071. show less