Why Fish Oil is a Better Source of Omega-3s than Krill Oil

All About Science

There’s a long-standing debate over which is a better for you, fish oil or krill oil. Like any good debate, there are points to be made on both sides. But if you’re looking to get the most omega-3 EPA and DHA per serving, in the form that’s easiest for your body to absorb, fish oil supplements made from Arctic cod, sardines, and anchovies are your best bet. There are some good reasons why this is true, which we’d like to explain here.

The Deep Dive on Krill

First, the key differences: Fish oil is extracted from fatty fish such as Arctic cod, sardines, and anchovies, whereas krill oil is extracted from krill, shrimp-like marine invertebrates that live in large schools called swarms throughout the world’s oceans. Although tiny—measuring only about two inches in length and weighing about a gram when fully grown—krill play a big role in the health of marine ecosystems. Penguins, seals, fish, and even the largest animal on earth, the blue whale, depend on krill as their primary food source (Check out this rare video footage of a blue whale feeding on krill.). Without krill, the food webs that sustain all oceanic life would collapse.

Krill oil naturally contains astaxanthin, a carotenoid antioxidant that gives salmon and shrimp their reddish color. Astaxanthin has also been shown to have a diverse range of potential health benefits, including potent antioxidant activity.* It’s important to realize, however, that the studies on which those potential benefits are based use much higher doses of astaxanthin than those typically provided by krill oil supplements. The dosages of astaxanthin used in the majority of clinical trials have been in the 6-12 mg a dayrange, whereas leading krill oil supplements provide a fraction of that, with some delivering just micrograms of astaxanthin per serving. We recommend reading the “Supplement Facts” on the product labels to find out exactly how much astaxanthin a krill oil supplement contains. If you’re looking for the benefits of astaxanthin, you’re likely better off taking a separate astaxanthin supplement that provides a research-backed amount.

Krill oil also contains phosphatidylcholine, a phospholipid found abundantly in human cells. Phosphatidylcholine is an essential structural component of cell membranes, and recent research has investigated its other possible roles in human health. Phosphatidylcholine can be found in eggs, cow’s milk, seeds, soybeans, fish, and meats. The human body also naturally produces phospholipids.

Absorption Compared

Krill oil makers contend that krill oil is better absorbed than fish oil because the EPA and DHA in krill oil are in phospholipid form (versus the triglyceride form in fish oil). But only 8% of fatty acid molecules in krill are bound to phospholipids. In fact, 98.5% of all fatty acids found in nature are in the triglyceride-bound form, while hardly any natural fats are found as phospholipids. This is one reason why triglyceride form fish oils have been shown to be so well absorbed—the body is used to getting them.

One recent clinical trial of healthy volunteers compared omega-3 supplements from different sources (fish oil, salmon oil, and krill oil) by looking at the blood level increases in the omega-3 fats EPA and DHA after consuming the different supplements; the results found that fish oil was 227% more effective than salmon oil and 382% more effective than krill oil at increasing blood levels of EPA and DHA.

Even if phospholipid-form EPA and DHA are what you’re looking for, there are better, more potent alternatives than krill oil. Herring roe oil, for example, has a higher amount of phospholipid-bound DHA than krill oil, gram for gram. It also offers a broader spectrum of phospholipids than krill oil.

“If we had seen just one independent study where krill outperformed fish oil, we would have added krill oil to our product line years ago.”

–Joar Opheim, Nordic Naturals Founder and CEO

Less Potent and More Costly

Aside from purity, the single most important consideration for any omega-3 supplement is the amount of omega-3 EPA and DHA it gives you per serving. After all, getting enough EPA and DHA is why most of us take omega-3 supplements in the first place. Experts and organizations worldwide recommend a minimum of 500 mg/day of EPA and DHA.1-3 Virtually all krill oil supplements provide significantly less than that per serving.

Research shows that the benefits of EPA and DHA can increase with higher intakes.4 And for those of us with existing health challenges, scientific evidence supports the need for high intakes of EPA and DHA.5-8 Krill oil isn’t potent enough to deliver these higher doses in a reasonable serving size, because it can’t be concentrated the way fish oil can. Krill oil is too molecularly unstable to undergo the processing required to concentrate more EPA and DHA per serving. For this reason, krill oil manufacturers often add fish oil to their formulas to increase their EPA and DHA content.

You would need 14 soft gels from a leading krill oil manufacturer to get the same amount of omega-3 EPA and DHA found in one Ultimate Omega® 2Xsoft gel.

Adding fish oil to krill oil can increase a krill supplier’s manufacturing costs, and those costs are inevitably passed along to consumers. As a raw material, krill is much more expensive than sardines, cod, or anchovies. That’s because krill, which decompose quickly, must be kept alive in water tanks or frozen immediately after harvesting. This increases the cost of getting fresh raw material to shore for processing into omega-3 supplements—another cost which is generally passed along to consumers. Cost comparisons have shown krill oil to be three to four times higher than the cost of high-quality fish oil, based on 500 mg EPA and DHA per serving.

More Science Backs Fish Oil

Fish oil remains among the most researched supplements ever, with more than 16,000 studies published to date. There are only a small number of published scientific studies investigating krill oil’s health benefits, many of them sponsored by the manufacturers themselves.

“If we had seen just one independent study where krill outperformed fish oil we would have added krill oil [to our product line] years ago,” says Joar Opheim, Nordic Naturals’ Founder and CEO. “The research is not there,” Joar said. Krill has a long way to go to catch up with the thousands of scientific studies published on fish oil.

The bottom line: while both krill oil and fish oil are sources of the omega-3s EPA and DHA that we all need for optimal health, a high-quality fish oil product offers many times more EPA and DHA per serving, at a significantly lower cost, with the scientific backing of decades of clinical research. Fish oil is just a better choice for getting your omega-3s, doing more for your health and your wallet.

*These statements have not been evaluated by the Food and Drug Administration. These products are not intended to diagnose, treat, cure, or prevent any disease.

1. AHA Scientific Statement: Fish Consumption, Fish Oil, Omega-3 Fatty Acids and Cardiovascular Disease, #71-0241. Circulation 2002;106: 2747–2757.
2. American Dietetic Association and Dietitians of Canada. Position of the American Dietetic Association and Dietitians of Canada: Dietary Fatty Acids. Journal of the American Dietetic Association 2007;1599–1611.
3. World Health Organization. Diet, Nutrition and the Prevention of Chronic Diseases. Technical report series 916.
4. Winwood RJ, Cope MB, Rice HB. Reduction in Chronic Disease biomarkers and very high intake of EPA and DHA omega-3 fatty acids. Advances in EPA & DHA Research vol 03;(02), 2010.
5. Sublette ME, Ellis SP, Geant AL, Mann JJ. The Journal of clinical psychiatry 2011, 72:1577-1584.
6. Ballantyne CM, Braeckman RA, Soni PN. Expert opinion on pharmacotherapy 2013, 14:1409-1416.
7. Bloch MH, Qawasmi A. Journal of the American Academy of Child and Adolescent Psychiatry 2011, 50:991-1000.
8. Martins JG. Journal of the American College of Nutrition 2009, 28:525-542.

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