Study: Krill Oil Omega-3s More Bioefficient than Fish Oil?

Omega-3s from krill oil may be more bioefficient than omega-3s from fish oil, according to research published in the January issue of the journal Lipids.

Partially funded by krill oil ingredients supplier Aker Biomarine (Oslo, Norway), the study assessed the effects of krill oil and fish oil on blood plasma levels of the omega-3s EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid) in 113 subjects. Differences in markers of oxidative stress and inflammation were also evaluated.

Subjects were randomized for daily supplementation of either six capsules of krill oil (3.0 g/day, 543 g of EPA and DHA), three capsules of fish oil (1.8 g/day, 864 g of EPA and DHA) or control for seven weeks.

As expected, krill and fish oil subjects experienced increases in plasma omega-3 levels, but control subjects did not.

Within the active groups, even though the dosage of EPA and DHA from krill oil was only 63% that of fish oil, both groups maintained similar levels of each omega-3. This finding would suggest that krill oil might be a more bio-efficient omega-3 source than fish oil.

Markers for oxidative stress and inflammation were comparable for both active groups.

“Essentially, while fish oil and krill oil are both excellent sources of EPA and DHA, there are differences,” said Eric Anderson, vice president of sales and marketing for Aker Biomarine’s North American market in an interview with Nutritional Outlook. “In fish oil, the fatty acids are predominantly bound to triglycerides, while in pure krill oil the EPA and DHA is bound mostly to phospholipids…The phospholipid form seems to be more bio-efficient, resulting in similar circulating levels at a smaller dose.

Anderson notes that previous research studies have confirmed these findings.

For more coverage of omega-3 dietary sources, and the differences that may exist, look for Nutrition Outlook’s upcoming May print issue.