A krill oil craze has recently engulfed Korea after getting a lot of attention in the media as a superfood that contains healthy fats.
|A TV home shopping program features krill oil products, which have gained a
lot of interest from the public as a superfood offering health benefits. (Screen
captured from YouTube)
Krill oil is extracted from the bodies of Antarctic krill. Like fatty fish and fish oil supplements, krill oil capsules contain the omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Many species of whales also live on Krill shrimp and fatten up before breeding.
Local companies that market krill oil have touted that krill oil based on phospholipids has higher absorption and bioavailability than conventional fish oil omega-3. Some are claiming that the treatment can help with dieting, child brain growth, and dementia prevention. These alleged benefits have made krill oil one of the most popular health functional foods this year.
The krill oil enthusiasm is not without some adverse effects, however.
A recent study; titled "The importance of Antarctic krill in biogeochemical cycles," published in Nature Communications, has highlighted the prominent role of Antarctic krill in the cycling of nutrients in the Southern Ocean.
"The vertical migratory habits of Antarctic krill throughout the water column show they can influence both the deep carbon sink and stimulate surface primary production," the journal said. "As the Southern Ocean has a disproportionately important role in the global carbon sink, and productivity is limited in iron-deplete areas, the cycling of carbon, iron, and ammonium by Antarctic krill has a particularly significant role compared with krill in other regions."
Also, the life-history traits of all krill (e.g., large body size, swarming ability) potentially mean other krill species are important in biogeochemical cycles, the journal added. The journal stressed that given humanity's lack of knowledge of the true extent of krill's ability to regulate biogeochemical cycles, it is of great concern krill shrimp is the target of the largest fishery in the Southern Ocean.
Due to such negative impacts on the ecosystem, some pro-environmental supermarkets, including Whole Foods in the U.S., have banned the sale of krill oil.
"Krill are an important source of food for marine animals, including penguins, seals, and whales in the Antarctic," Whole Food said. "Declines of some predator populations in the areas where the krill fishery operates suggest that fishery management needs to understand better how to evaluate the prey requirements of other marine species to set sustainable catch levels for krill."
Consequently, at present, Whole Food is choosing to discontinue the sale of krill supplements as it continues to evaluate this emerging research, the company added.
Some companies in the U.K. have also announced they would replace krill oil supplements with algal oil-based omega-3 products and other fish alternatives on the back of a Greenpeace report on krill fishing's impact in the Arctic.
However, excessive fishing in the Southern Ocean is just part of the controversy that shrouds krill shrimp as scientists and physicians are also a hot debate on whether or not omega-3, the main ingredient of krill oil, is indeed helpful in preserving one's health.
Those in favor of the health benefits say that omega-3 in krill oil can improve memory and learning ability and helps the brain development of children, help prevent dementia in the elderly, maintain vision, and improve liver function.
Those who oppose the health benefits of omega-3 say that it has little or no benefit for heart health or strokes.
Cochrane, an organization that compiles and evaluates medical research for the general public, released a meta-analysis, which determined whether or not omega-3 pills reduced the risk of coronary heart disease.
After comparing 79 tests involving 112,059 people, the researchers could find little or no difference to risk of cardiovascular events, coronary heart deaths, coronary heart disease events, stroke, or heart irregularities.
Despite such controversies, krill oil is still a popular item in Korea.
"A lot of patients ask me if they should eat krill oil," a local physician wrote on his Facebook account while asking to be quoted with anonymity. "It is a matter for individuals to decide whether to sell or eat food. However, since it is a health question when the evidence is not appropriate, I do not give a positive answer."
Before people can debate whether or not krill oil is good for a person, however, it appears to be undoubtable that it is bad for the environment, he added.
The doctor noted that when patients ask him if they can eat krill oil, he replies, "I don't know much about the health effects of krill oil. As it is a major food source for whales, however, shouldn't whales have something to eat as well?"
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