Both fish-oil pills and krill-oil supplements supply the healthful omega-3 fatty acids DHA and EPA. But there are differences. Krill oil comes from small crustaceans, not fatty fish, and typically contains more EPA. And unlike conventional fish-oil pills, krill oil’s omega-3s are linked to an antioxidant and other potentially beneficial substances called phospholipids, which sound appealing.
But we found a surprising dearth of recently published clinical research comparing the potential health benefits of krill-oil supplements with fish oil. Here’s a roundup of some early studies:
Heart health. Omega-3s from fish-oil pills and fatty fish can reduce the risk of heart attacks and strokes, research has found. Now investigators have demonstrated that it’s possible to attain the same heart-healthy levels of omega-3s recommended by the American Heart Association from krill-oil supplements, according to a study in the January 2011 issue of the journal Lipids. In a clinical trial lasting seven weeks, researchers from Norway and Sweden analyzed the data from 113 female and male volunteers.
Tests found that blood levels of DHA and EPA increased just as significantly in both the groups that took krill oil and fish oil compared with people in a control group, suggesting that omega-3s from krill oil are at least as available to the body as those from fish oil.
Arthritis symptoms. Krill oil helped people with arthritis by reducing pain, stiffness, loss of function, and inflammation as measured by serum C-reactive protein, or CRP, which is linked with chronic inflammation, according to a clinical trial at the University Health Network in Toronto. Among the findings: Neptune brand krill oil reduced pain much more than a placebo, and CRP levels fell a significant 31 percent among those taking krill oil compared with a 25 percent rise among those in a placebo group, according to the study, published in the February 2007 issue of the Journal of the American College of Nutrition.
Premenstrual syndrome. Neptune brand krill-oil supplements reduced PMS symptoms and painful menstruation much more than fish-oil pills, according to a report in the May 2003 issue of Alternative Medicine Review. (The Canadian team included two authors who worked for the company that sold Neptune Krill Oil.) Krill-oil supplements were statistically more effective in managing self-reported emotional symptoms, breast tenderness, and joint pain. There was no significant difference between the two oils in managing weight gain, abdominal pain, or swelling.
Neptune Technologies’ Neptune Krill Oil supplement was listed in a Food and Drug Administration “import alert” issued in July 2011, which advised field personnel that they could detain shipments of allegedly unapproved and/or misbranded products. A Neptune Technologies representative says the matter involved marketing material for its supplement. Since then, Neptune claims to have modified labels and advertising materials and is working with the FDA to lift the import alert. (June 11, 2012, update: Representatives for Neptune Technologies informed Consumer Reports that the June 8, 2012, FDA import alert no longer lists the company or its krill-oil supplement.)
Bottom line. More clinical research is needed. Most people can get enough DHA and EPA by eating fatty, low-mercury fish—such as Alaskan salmon and sardines—at least twice weekly.
If you take a supplement, consult a doctor because krill oil and fish oil may interact with some drugs, including blood thinners.
Fish-oil supplements are probably safe for most people in doses of 3 grams or less a day. There are no formal standards for krill oil, but the U.S. Pharmacopeia (USP), a nonprofit
authority that works to verify supplements, is developing them. You can buy krill supplements in drugstores, health-food stores, and online. The price per pill can start around 30 cents, about what you’ll pay for some fish-oil capsules.