Lack of effect of supplementation with EPA or DHA on platelet-monocyte aggregates and vascular function in healthy men

- We investigated the separate effects of EPA and DHA (3 g/d, 6wks) on vascular and platelet function in healthy men.
- Neither EPA nor DHA influenced platelet monocyte aggregates or capillary density.
- EPA, but not DHA, improved a marker of insulin sensitivity.

Background and AimsEicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) found in fish oil are postulated to have favourable effects on platelet, endothelial and vascular function. We investigated whether EPA has differential effects on in vivo platelet aggregation and other markers of cardiovascular risk compared to DHA.Methods and ResultsFollowing a 2 wk run-in taking encapsulated refined olive oil, 48 healthy young men were randomly allocated using a parallel design to receive EPA-rich (3.1 g EPA/d) or DHA-rich (2.9 g DHA/d) triglyceride concentrates or refined olive oil (placebo), for a total supplementary lipid intake of 5 g/d. The specified primary outcome was change in platelet monocyte aggregates (PMA); secondary outcomes were capillary density, augmentation index, digital pulse volume measurements, 24 h ambulatory BP, plasma 8-isoprostanes-F2α. Changes in the proportions of DHA and EPA in erythrocytes and non-esterified fatty acid composition indicated compliance to the intervention. There was no significant treatment effect on PMA (P = 0.382); mean changes (%) (95% CI) were placebo −0.5 (−2.0, 1.04), EPA 0.4 (−0.8, 1.6), DHA 0.3 (−1.5, 2.0). R-QUICKI, an index of insulin sensitivity, was greater following EPA compared to placebo (P < 0.05). No other significant differences were noted.ConclusionNeither EPA- nor DHA-rich fish oil supplementation influence platelet-monocyte aggregation or several markers of vascular function after 6 wk in healthy young males. This trial was registered at clinicaltrials.gov as NCT01735357.