K rill oil has made quite asplash in the supplement world, but is it alljust marketing and hype or is there science to support its use?
Krill are shrimp-like crustaceans that contain the healthyomega-3 fats. Much like fish oil, krill contains bothdocosahexaenoicacid (DHA) and eicosapentaenoic acid (EPA), but in lesseramounts. Omega-3 fats are "essential," meaning theymust be obtainedfrom the diet and cannot be produced endogenously.
Omega-3 fats like the ones in krill oil are known for theiranti-inflammatoryproperties, help reduce high triglyceride levels and are oftenused to help treatcardiovascular disease. Impressive, since most people think fatis bad for you!
The true key, though, is whether krill oil is just as or moreeffective thanother sources of omega-3s, like fish oil.
Krill is a source of EPA and DHA, but most of the science inthat area comesfrom other sources of these fatty acids. That is likely becausewhile krill oil doescontain DHA and EPA like fish oil, it has recently beendetermined that krill oilcontains approximately 63% of the omega-3 fats found in fishoil.
A study in 2009 did use krill oil supplementation to determineif 2 g/day increasedplasma concentrations of EPA and DHA. The researchers found thatafter supplementing with 2 g krill oil/day, EPA and DHA levelswere significantlyincreased and the supplement was well tolerated, which isimportant.
One of the prime "arguments" for proponents of krilloil is that it is morebioavailable, so less EPA and DHA are needed, and it is a goodsource ofthe antioxidant astaxanthin.
Without data comparing the two in terms of specific outcomemarkers, it'simpossible to say if krill is more effective than fish oil.Also, most of the studiesconducted using astaxanthin (12-18 mg/day), used significantlyhigher dosesof the antioxidant than is available in most krill oilsupplements (1-2 mg/day).
While omega-3 supplements have been shown to be safe, toxicitysymptomsassociated specifically with krill oil supplements are not wellstudied.Fish oil supplements, especially in excess of 3 to 4 grams ofEPA and DHAper day, can cause fishy burping, heartburn, nausea, loosestools and rash.
The assumption would be that krill oil would have similar effectsbutstudies to date have not been conducted like they have with fishoil.
"Considering the much higher price for krill oil [versusfish oil], the potentiallysmall increase in bioavailability may not be worth it. Until wehavedata comparing fish oil to krill oil on intermediate markers ofrisk (triglyceridelevels, vascular function, etc.) and actual disease endpoints(CHDdeath, heart attacks) we won't be able to say one is better thanthe other."
--William Harris, PhD, world-renowned omega-3 expertDr Chris Mohr is the creator of Dietary SupplementUniversity (www.DietarySupplementU.com), theleadingresource for the most up to date reviews ofingredientsand dietary supplements).