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Krill oil increases omega-3 index in healthy adults, study shows


  • Krill oil supplementation significantly increases omega-3 index in healthy adults
  • Omega-3 index increase with krill oil is over 1%, twice as much as with fish oil
  • Effective omega-3 dosage is 600 mg/day (providing 155 mg/day EPA and DHA combined)


This randomized, double-blind, placebo-controlled, crossover trial was designed to assess the effects of krill oil compared to fish oil or a placebo on plasma and red blood cell (RBC) fatty acid profiles in healthy adults.

For this study, researchers recruited 24 healthy young adults, mean age 28 years, who were given one of three treatments in random order: krill oil, fish oil, or a placebo (corn oil).  The daily dosages of krill oil (3 g/day) and fish oil provided 600 mg/day omega-3 fatty acids with similar amounts of EPA and DHA in the krill oil (98 mg/day EPA and 57 mg/day DHA) and fish oil (81 mg/day EPA and 52 mg/day DHA) treatments. Krill oil also provided 1,800 mcg/day of astaxanthin in addition to the fatty acids. Each treatment lasted 4 weeks, separated by 8-week washout phases.

All participants (12 men and 12 women) completed the study. No adverse or serious adverse events related to the treatments were reported.

Compared to fish oil, krill oil significantly (P<.05) increased plasma and RBC levels of EPA and DHA and reduced the omega-6:omega-3 ratio in plasma and RBCs. Compared to fish oil, krill oil also significantly (P<.05) increased the omega-3 index by 1.04%, which was twice the increase seen with fish oil (0.47%). The omega-3 index is an emerging indicator of heart health.

No changes were reported for triglycerides or HDL-cholesterol with any treatment. Krill oil, similar to fish oil, resulted in a slight but statistically significant (P<.05) increase in total cholesterol (average increase 13 mg/dL) and LDL cholesterol (average increase 8 mg/dL) compared to corn oil without altering the HDL-cholesterol or triglycerides with no change in TC/HDL ratio.

These findings suggest that supplementation with krill oil is more effective than fish oil for improving the omega-3 index.


Ramprasath VR, Eyal I, Zchut S, Jones PJ. Enhanced increase of omega-3 index in healthy individuals with response to 4-week n-3 fatty acid supplementation from krill oil versus fish oil. Lipids Health Dis. 2013;12:178.

PMID: 24304605