Fish Oil vs Krill Oil: Are There Differences and any Real Benefits?

The consumption of fish oil supplements, derived from cold water fishes, has been recommended by physicians for several years now due to the substantial amount of laboratory and clinical data demonstrating benefits to cardiovascular and brain health. Although less familiar to the lay public, there are other sources of the same healthy oils found in cold water fishes such as Krill oil supplements, and for Vegans there is the blue-green algae, Spirulina, that is a great source of these healthy oils.

So what are the healthy oils found in these supplements? Each of the 3 supplements I mention are beneficial from the presence of long-chain polyusaturated fatty acids (PUFAs) that are of the family called the omega-3 PUFAs. These PUFAs are called eicosapentaenoic acid (simply EPA) and docosahexaenoic acid (simply DHA). Briefly, the term omega-3 refers to the fact that there is a carbon-carbon double bond (a site of unsaturation) three carbons from the omega end of the molecule. Fatty acids are so-called because they have an acid group (a carboxylic acid) at one end. The omega end is the other end of the fatty acid. There are two functionally significant classes of omega PUFAs. One is the omega-3 PUFAs and the other is the omega-6 PUFAs. Greater detail about the biosynthesis, distribution, and functions of the omega PUFAs and the benefits of Krill oil supplements can be found in my website:

The basic biological difference is that omega-6 PUFAs promote inflammatory processes, whereas, omega-3 PUFAs control the intensity of an inflammatory event. This interplay allows inflammation to occur when it should but doesn't allow it to run rampant. Inflammatory processes within the vasculature, if unchecked, are a prevalent contributor to coronary artery disease. The typical healthy diet should have a ratio of approximately 2:1 (omega-6:omega-3) but unfortunately the typical Western diet eaten by most Americans, contains a ratio approaching 50:1. This means that inflammation in the blood vessels can go unchecked and at vastly elevated levels which contributes to the cardiovascular diseases associated with the Westernized diet.

The major benefit of Krill oil over fish oil is the way in which the EPA and DHA are "packaged" and how this difference contributes to absorption from the gut and distribution in cells in the tissues, the details of which can be read in the page in the link above. Evidence suggests that EPA and DHA from Krill oil are better absorbed and more effectively distributed to the tissues. However, other evidence suggests that there is no difference, at least when assessing the level of EPA and DHA in the blood. The problem arises from the fact that the amount of EPA and DHA in Krill oil supplements is much lower than that in fish oil supplements and there has been inconsistencies in the way various studies have been carried out. When examining tissue distribution it seems clear that Krill oil intake results in a higher rate of EPA and DHA incorporation into tissues.

So until other evidence indicates to the contrary my recommendation is to use Krill oil supplements not only because of the better tissue incorporation of EPA and DHA with Krill but also because Krill oil is enriched in a potent anti-oxidant compound called astaxanthin (this is what makes Krill oil red).

As to the health benefits, there is little question that DHA consumption in the post-natal period benefits development of the brain and numerous reports have demonstrated a clear link between EPA and DHA consumption and reduced levels of LDL-c (low density lipoprotein associated cholesterol), the so-called "bad cholesterol" and elevation in HDL-c (high density lipoprotein associated cholesterol), the so-called "good cholesterol". However, a recent report from the American Heart Association suggests that fish oil supplements show no benefits at preventing heart disease in the general population, but that in patients who have had a cardiac event, the consumption of fish oil supplements may contribute to the prevention of another heart attack.

So what to do?? Clearly attempting to prevent cardiovascular disease solely by taking a fish oil supplement is not going to suffice. One needs to address all of the contributing factors such as diet and physical activity. However, in the context of an overall healthy lifestyle and in the context of disease risk reduction, there is NO question that the PUFAs, EPA and DHA, should be a part of ones diet and the scientific evidence suggests that Krill oil may be the more useful source of these fats. Again for Vegans that choiuce would be Spirulina supplements.


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