Bioavailability of marine n-3 fatty acid formulations.
Level 2 - randomized trial
Individual controlled clinical trial comparing multiple formulation arms
PubMed 20638827 · doi:10.1016/j.plefa.2010.06.007
What was done
In a controlled clinical trial, 72 volunteers received approximately 3.3 g/day of eicosapentaenoic acid (EPA) plus docosahexaenoic acid (DHA) for 2 weeks across different preparations. Three concentrated formulations (ethyl esters, free fatty acids, and re-esterified triglycerides) were compared with placebo oil in a double-blinded design, and with natural fish body oil and cod liver oil in single-blinded arms. The primary outcome was the increase in absolute amounts of EPA and DHA in fasting serum triglycerides, cholesterol esters, and phospholipids.
What was found
Relative to natural fish oil, the bioavailability of EPA+DHA was superior for re-esterified triglycerides (124%) and inferior for ethyl esters (73%). Free fatty acid bioavailability was 91% (no statistically significant difference from natural triglycerides). Fatty acid stereochemistry in acylglycerols did not influence EPA and DHA bioavailability.
Why it matters
This study demonstrates that the chemical formulation of omega-3 supplements significantly impacts systemic lipid absorption, with re-esterified triglycerides showing higher short-term bioavailability than ethyl esters.
Limits
The intervention lasted only 2 weeks, sample size was relatively small (72 participants split across multiple arms), some comparison arms were single-blinded rather than double-blinded, and clinical endpoints or long-term tissue incorporation were not evaluated.
Cited by
- supports The human body absorbs significantly less omega-3 in ethyl ester form compared to the re-esterified triglyceride form.