|Fish Oil vs. Krill Oil
|More and more people are taking ﬁsh oil and other marine supplements. Why? Because of the extensive health beneﬁts of increased omega-3 intake. Backed by over 40 years of research, omega-3s—eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)—are essential fatty acids; “essential” means that the body cannot produce these good-for-us fats, hence they must be consumed from diet or supplements. Today the scientiﬁc consensus is so strong that health policy makers worldwide, including the American Heart Association (AHA) and the World Health Organization (WHO), all agree that omega-3s maintain health and prevent disease. Omega-3 supplements are one of the fastest growing categories of supplements, and there is an ever-growing array of omega-3 products for the consumer to choose from.
What is Krill?
Recently some companies have started selling krill oil supplements as a source of omega-3. Krill are shrimp- like crustaceans that are a dietary staple for whales, small ﬁsh, and seabirds. Krill exist in large numbers and are an integral part of the aquatic food chain.
The increased ﬁshing of krill has lead to grassroots protests and a call to action by The National Oceanic and Atmospheric Administration (NOAA). Scientists, ﬁshery groups, and federal environmental organizations like the NOAA have all voiced concerns about the potential impact of increased krill ﬁshing. Due to these concerns, the ﬁshing of krill has been banned on the West Coast of the US, and has been strictly limited in places like Norway and Antarctica1. In contrast, ﬁsh oil supplements are predominantly produced from sardines and anchovies, species that are currently in abundant supply, ﬁshed well below mandated limits, and are considered ideal species for sustainability, given their short reproductive cycles. A study published in the journal, Science, by marine conservation biologists also suggested that ﬁshing should concentrate more on these pelagic species, in order to reduce the dependence on ﬁsh species currently threatened by overﬁshing2.
Whereas krill oil generally provides 7–24% omega-3s (EPA and DHA), and about 0.2% astaxanthin, a reddish carotenoid pigment, ﬁsh oil naturally contains about 30% omega-3s (EPA and DHA). Concentrated ﬁsh oil formulas, produced through molecular distillation or other processing of natural ﬁsh oil, contains up to 98% omega-3s (EPA and DHA). Fish oil also typically contains 0.25–0.50% antioxidants as added oil stabilizers.
Krill contains the antioxidant, astaxanthin, which makes up 0.2% of the oil by weight. This percentage is not sufficient to offset krill’s rapid decomposition, which occurs in only 2–3 hours. Fish oil has a signiﬁcantly longer interval of decomposition, about 48–72 hours, which allows ample time for processing with very low oxidative stress. Techniques for optimizing the stability of ﬁsh oil have been extensively researched and have long been established; adding approximately 0.25– 0.5% of vitamin E and rosemary extract (fat-soluble antioxidants) have been proven to be the most effective technique for maintaining oil freshness. This combination of antioxidants provides, at a minimum, an equal Oxygen Radical Absorbance Capacity (ORAC) value when compared to krill oil.
To date, there are only 3 published human studies conducted with krill oil, whereas over 8,000 clinical human studies have been published on ﬁsh oil. Marketing of krill oil has recently included claims about being “faster absorbed,” “more rich than ﬁsh oil,” etc., which has triggered the involvement of the National Advertising Division of the Council of Better Business Bureau www.nadreview.org/ CaseReports.aspx). A review of the literature shows no evidence or supportive studies for these claims. In response, an agreement has been reached to stop
advertising these unsubstantiated claims.
Even though the US government has not set speciﬁc criteria for ﬁsh oil products, most ﬁsh oil manufacturers hold themselves to strict international standards for safety and purity. (For the strictest purity guidelines in the world, please refer to The World Health Organization). Any ﬁsh oil manufacturer that prioritizes quality should be able to supply third-party test results to prove purity and ensure compliance with quality standards. In fact, over 50 ﬁsh oil manufacturers have had their products tested for impurities by the Environmental Defense Fund, and the majority received commendations for conforming to the strictest standards for safe levels of contaminants and toxins.
In order for an oil to reach maximum absorption AND utilization by the body, it needs to be fresh. Freshness is measured by laboratory methods that evaluate the degree of oxidation in the oil, which is measured in terms of the oil’s peroxide value and anisidine value. Oxygen breaks apart the bond of omega-3 molecules and creates free radicals, which can have a negative effect on human health. Whether produced from krill or ﬁsh, omega-3s that have been oxidized (i.e. that are not fresh) often have a poor taste and smell, and will not supply the health beneﬁts for which these essential fatty acids are known. Consequently, the freshness values (peroxide and anisidine values) of the omega-3 supplement are crucial to avoiding poor taste, achieving optimal absorption, and thus to receiving the health beneﬁts of increased omega-3 consumption.
Consider the Fat
When manufacturing a raw material for its omega-3 content, it is important to consider its fat percentage. Sardines and anchovies yield greater than 80% fat, while krill yields less than 5% fat, which causes decomposition to occur within hours and thus becomes a signiﬁcant obstacle for its manufacture. To reduce decomposition and oxidation, krill need to be kept alive in water tanks, or frozen until processing. This substantially increases the cost of getting the raw material to shore for processing. As a result, the average wholesale cost for krill oil is around $230/kg, compared to natural ﬁsh oil that is priced around $10/kg. Given these considerations, sardines and anchovies are not only more ecologically sustainable but also a more economical source for omega-3 supplements.
Is Krill Oil Pure?
Due to the high cost of the krill raw material explained previously, it is not uncommon for manufacturers to mix krill oil with ﬁsh oil. Astaxanthin and phospholipids (PL) can also be added to mimic 100% krill oil. Claims of krill’s superior absorption (which are now ending due to the National Advertising Division’s involvement) are based on PL and DHA levels. Krill oil contains under 10% DHA, on average. Fish oil contains a minimum of 12% DHA, increasing to over 75% after concentration. Although ﬁsh oil initially has no DHA bound directly to PL (but rather it is a triglyceride), it is easily bound to PL in the body. In fact, all DHA molecules in the human body are bound to PL. Fish oil also contains a minimum of 18% EPA, which, along with DHA, is the other health-promoting omega-3. Krill contains about 14% EPA.
The ﬁsh oil industry has driven the development of technology to greater and greater precision for detecting environmental toxins such as mercury, heavy metals, PCBs, dioxins, pesticides, and other toxins (some of which are nameless as of yet.) This technology can quantify these molecules down to parts per billion and even parts per trillion. Properly manufactured, high quality ﬁsh oils have no detectable contaminants, even at these extremely low levels, and should be able to verify that purity with third- party lab results.
Although, at this point in time, not all ﬁsh oil or krill oil companies follow international quality standards, ﬁsh oil does have a proven record of safety, efﬁcacy, purity, and sustainability when manufactured according to the standards of the European Pharmacopeia and the World Health Organization. There may be more science behind omega-3 essential fatty acids than any other single natural supplement. Research has shown that omega-3s beneﬁt every cell, tissue, organ, and system in the human body and that the best source of omega-3s is a high quality ﬁsh oil supplement.
1 By the states of California, Oregon, and Washington, in response to groups such as NOAA, Paciﬁc Fishery Management Council, Antarctic and Southern Ocean Coalition, Convention on the Conservation of Antarctic Marine Living Resources, The Ocean Research Institute of Norway, and Antarctic Krill Conservation Project (www.krillcount.org).
2 Boris Worm, et al. Impacts of Biodiversity Loss on Ocean Ecosystem Services. Science 2006;314:787–790.