Krill, a tiny marine creature, comes up big as a source of omega-3 fatty acids.
By Lisa James
Not too many nutrients have attracted the kind of research attention paid to omega-3 for the better part of two decades. A search of PubMed, the US Library of Medicine’s index of biomedical studies, returns more than 9,000 entries covering the past 10 years alone.
Much of that research has focused on docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), the omega-3s in fish oil. DHA and EPA have been associated with health benefits that include cardiovascular well-being, cognition and mood support, and joint protection.
Fish isn’t the only source of DHA and EPA, however. Krill, a shrimp-like crustacean, concentrates DHA and EPA in its tissues along with other important nutrients. While each of these creatures may be tiny, they gather in large swarms—making krill a potent new source of marine-based omega-3.
Good health starts with the body’s trillions of cells. Each is surrounded by a membrane that not only holds the the whole thing together but also acts as a gatekeeper, allowing various substances to enter and leave the cell.
Cell membranes are made up of a substance called phospholipid (PL) that contains omega-3s, which gives PL flexibility and resiliency. In contrast with fish oil, krill oil provides EPA and DHA in PL form, making it easy for the body to absorb and use.
Disruption of the cell membrane can affect the cell’s ability to do its job. Ironically, it is an essential cellular function—energy production—that can prove hazardous. This process leads to the creation of unstable molecules called free radicals that may damage the membrane, causing it to become stiff and unresponsive.
Krill oil contains an antioxidant called astaxanthin, which neutralizes free radicals and prevent damage to not only the cell membrane but other cellular components as well. A team of Chinese scientists reviewed the available research and wrote, “Numerous studies have shown that astaxanthin has potential health-promoting effects in the prevention and treatment of various diseases,” including cancer along with cardiovascular, neurological and liver disorders (Molecular Nutrition & Food Research 1/11).
Scientists are also making the connection between krill oil and enhanced health. In rats, krill oil has reduced cholesterol levels and cardiac damage caused by heart attacks (Lipids in Health and Disease 8/29/08, 12/29/11 online). Other studies show a link between krill oil and reductions in inflammation, arthritis and a bowel disorder called colitis.
As beneficial as omega-3 fatty acids are to human health, many of the world’s fisheries are being depleted by over-harvesting—including a number of species used to create fish oil. On the other hand, the krill fishery off of Antarctica is managed by a 25-nation consortium called the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR). This group manages the fishery with an eye towards maintaining healthy krill stocks over the long term.
Krill oil does come with one caveat: It is fragile and easily damaged by exposure to oxygen. That’s why krill oil is best processed using nitrogen as a barrier between the oil and the air, which reduces the risk of oxidation. Some suppliers use an extract from the herb rosemary, a powerful anti-microbial agent, to further protect krill oil from contamination.
Omega-3 fatty acids will continue to play a crucial role in maintaining human health, just as krill oil will continue to become a more crucial source of this nutrient.