A study published in Lipids in Health and Disease compares the bioavailability of fatty acids from krill oil and fish oil in healthy humans.
Krill contains two marine omega-3 polyunsaturated fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), mainly bound in phospholipids. Typical products from krill are krill oil and krill meal. Fish oils contain EPA and DHA predominantly bound in triglycerides. The difference in the chemical binding of EPA and DHA has been suggested to affect their bioavailability, but little is known on bioavailability of EPA and DHA in krill meal. In this study, the researchers set out to compare the acute bioavailability of two krill products, krill oil and krill meal, with fish oil in healthy subjects.
A randomized, single-dose, single-blind, cross-over, active-reference trial was conducted in 15 subjects, who ingested krill oil, krill meal, and fish oil, each containing approximately 1,700 mg EPA and DHA. Fatty acid compositions of plasma triglycerides and phospholipids were measured repeatedly for 72 hr.
The researchers found that EPA and DHA in krill oil had a higher 72-hr bioavailability than in krill meal or fish oil. Their findings that bioavailabilities of EPA and DHA in krill meal and fish oil were not different argues against the interpretation that phospholipids are better absorbed than triglycerides. They noted that longer-term studies using a parameter reflecting tissue fatty acid composition, like erythrocyte EPA plus DHA, are needed.