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

Randomized, double-blind, crossover, single-center trial at King's College London in the United Kingdom. Each active meal arm included 16 nonsmoking healthy men aged 35-70 years with higher than optimal fasting triglyceride concentrations; mean age was 49.9 ± 11.4 years and mean BMI was 27.3 ± 3.9 kg/m2.

Participants consumed single oral high-fat test meals enriched with either 5 g EPA plus DHA from fish oil (Incromega TG4030-(LK)) or 5 g DHA from marine microalgal oil (DHASCO). Outcomes were followed for up to 6 h postprandially, with comparison against a high-oleic acid control meal and a linoleic-acid-rich meal in the crossover design.

Overall, EPA plus DHA fish oil and DHA-only algal oil produced different acute postprandial oxidative stress responses, but neither meal consistently improved postprandial lipemia or vascular function. Compared with the high-oleic acid control meal, TAG decreased after fish oil at 4, 5, and 6 h (P < 0.05), while algal oil reduced the magnitude of NEFA suppression during 0-3 h and showed higher NEFA at 1, 2, and 3 h vs control. The key divergence was 8-isoprostane F2alpha: fish oil increased it at 6 h vs control, whereas algal oil reduced it vs both control and fish oil. No differences were reported for NOx, AIx, or digital volume pulse indices, and no adverse effects occurred.

The active arms were small (16 participants each), which limits precision and power for secondary endpoints. This was an acute single-meal crossover study with only 6 h of follow-up, so it does not address longer-term cardiometabolic effects. Generalizability is limited to middle-aged, nonsmoking men with elevated fasting triglycerides from a single UK center.