Krill oil is an oil derived from shrimp-like crustaceans called krill. The omega-3-rich oil contains two of the same essential fatty acids as fish oil (eicosapentaenoic acid, or EPA, and docosahexaenoic acid, or DHA). The EPA and DHA in krill oil are said to have higher bioavailability (rate of absorption) compared to fish oil because much of the EPA and DHA in krill oil is bound to phospholipids.

For years, people have been taking fish oil supplements for the essential fatty acids contained inside, and more and more people have been turning to krill oil as an alternative. Its rise in popularity has raised some concerns about sustainability.

Health Benefits
Krill oil is often used for the same reasons as fish oil: to improve heart health and fight inflammation. Compared to fish oil, krill oil supplement contains higher amounts of astaxanthin—a carotenoid pigment that gives krill and other crustaceans their characteristic red-pink color. Unlike many other antioxidant substances, preliminary studies have found that astaxanthin may cross the blood-brain barrier and protect the brain and central nervous system from free radical damage.

The recent popularity of krill oil supplements has raised serious concerns that it could threaten populations of its predators, including penguins, seals, and whales.12

Besides nutritional supplements, commercially fished krill are used for aquaculture and aquarium feeds, sport fishing bait, and for food consumption. In Japan, krill is considered a delicacy and is called okiami. In 2010, Whole Foods Market stopped selling krill oil supplement, citing environmental concerns.13

It is important to purchase krill oil supplements that are certified as coming from sustainable sources. Look for a label certifying that the krill oil contained in the product comes from an MSC- and Friends of the Sea-certified sustainable fishery.4 This ensures that harvesting practices were subject to oversight by the Commission on the Conservation of Antarctic Marine Living Resources, which is working to protect 1.5 million square kilometers of krill habitat in collaboration with 24 countries and the European Union.