All fish oil capsules have some amount of anti-inflammatory activity, because of the essential fatty acids they contain. But, recent studies have shown that a fish oil capsule containing 500mg of natural triglycerides from the New Zealand hoki fish has anti-inflammatory activity equivalent to that of aspirin, which is more than double what is seen with a “regular” supplement.

Manufacturers have choices when they decide to sell fish oil capsules. They can choose what species of fish to use and decide whether or not to distill and concentrate it. If it is distilled the result is called an ester. If it is not distilled, it is called a natural triglyceride.

For many years, the use of molecular distillation was the best choice, because it concentrated the omega3 fatty acids and removed impurities like mercury. Now, it seems that the natural form has more anti-inflammatory activity, but since the concentration of omega3s would be lower, other health benefits would be lost.

There is a third choice. A fish oil capsule can contain 500mg of natural triglycerides and 500mg of concentrated esters. In that way, the omega3 content is higher than what is found in most supplements, but the anti-inflammatory activity is left intact.

Why a fish oil capsule containing the natural triglycerides would have a higher level of anti-inflammatory activity is unknown. Sometimes, it is impossible to isolate a single component of a naturally occurring substance that is responsible for its medicinal activity. Sometimes, it is a combination of all of the naturally occurring nutrients that is responsible.

For example, researchers have tried to find the compound that is responsible for the health benefits of red wine. When they identified resveratrol, they believed that had it. But, later studies showed that it could not possibly be resveratrol, alone, that was responsible for the health benefits, because the amount in the wine was far too low.

It has been difficult to explain the anti-inflammatory activity of fish oil capsules, too. Researchers have tried to identify what biological pathways are affected by omega3 fatty acids. It is known that bio-chemicals produced from omega3s have less inflammatory activity than those produced from omega6s. But, that would increasing omega3s in the diet would only have the affect of modulating inflammation.

If it has a high degree of anti-inflammatory activity, a fish oil capsule can relieve aching joints and protect the cells of the body from the negative affects of chronic inflammation. Diseases like rheumatoid arthritis and inflammatory bowel are improved through the use of fish oil capsules.

There are benefits to the heart, as well, because inflammation is involved in atherosclerosis or hardening of the arteries. Skin conditions like acne, eczema and psoriasis improve when a person takes a fish oil capsule. But, all of these benefits are dependent on the anti-inflammatory activity.

Manufacturers can have their fish oil capsules tested for anti-inflammatory activity. The better manufacturers publish the results on their websites. Of course, testing costs money and most manufacturers are not willing to pay the price. So, this is not something that you will commonly see. If you want the best, it pays to look for it.