Information about Krill Oil

Since fish oil capsules are so common, manufacturers keep trying to come up with products that stand out from the crowd in order to justify a premium price. Thus you see widely promoted Norwegian or Icelandic brands of fish oil supplements, for instance, though there's no clear evidence that these supplements are superior.

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When it comes to marketing, krill oil supplements have been making the loudest claims.

A better fish oil?

Krill are thumb-sized, shrimp-like crustaceans that thrive especially in Arctic and Antarctic waters and feed off plankton. In turn, whales, penguins, seals, and fish eat krill. Like other marine oils, krill oil is rich in heart-healthy omega-3 fats. According to the marketers' websites, krill oil is more potent, better tolerated and better absorbed than fish oil, and also richer in antioxidants.

It's claimed that krill oil is better at lowering cholesterol, reducing arthritis pain and stiffness, and boosting the immune system and brain function—not that any marine oil can do all this.

Contributing to the hype about krill was the recent approval by Health Canada (which functions like the U.S. FDA) for a wide variety of these health claims—at least for one particular product, Neptune Krill Oil (NKO), whose Canadian producer sought the agency's okay.

What's the real deal? Chemically, krill oil differs somewhat from fish oil. It contains tiny amounts of astaxanthin (a carotenoid and reddish pigment), as well as some choline (related to the B vitamins) and an unusual type of flavonoid. But none of this necessarily means that krill oil supplements have significantly different biological effects from fish oil.

Three other krill concerns

About the same time that Health Canada gave NKO a thumbs up, the supplement-testing company gave it a thumbs down. It found that NKO capsules contained lower levels of omega-3s than stated on the label and often had signs of spoilage—even in newly opened bottles. Another krill product was found to contain little krill oil (12 percent krill, the rest fish oil), despite a premium price.

Then there's the ecological issue. Though the industry says that krill populations are plentiful, there's been concern that krill, essential in the marine food chain, have been declining due to climate change. Excessive harvesting of krill for supplements may worsen the situation.

Finally, krill supplements can trigger reactions in people who are allergic to shrimp and other crustaceans.

Source: Originally published in The University of California, Berkeley Wellness Letter (July 2011

Publication Review By: the Editorial Staff at

Published: 22 Jun 2011

Last Modified: 17 Mar 2015