Although regulated by the Food and Drug Administration in the United States, dietary supplements do not undergo rigorous testing in terms of efficacy prior to becoming available on the market, as many consumers believe. In fact, most supplements are given very little attention unless ill effects are reported. Compound this fact with the broad availability of supplement brands and the elaborate marketing campaigns that promote them, it can be difficult to know how to choose between them. While fish oil capsules are one of the few supplements the FDA allows to carry a health claim, knowing what to buy can still be confusing. However, there are several key things to look for on the label that will help the better product to stand out.
First, check for balance in the formulation of fish oil capsules. Most people are aware that fish oil contains beneficial essential fatty acids, or EFAs. For this reason, fish oil is often used interchangeably with the term "omega-3," a polyunsaturated fatty acid and a source of alpha-linolenic acid (ALA). Omega-3 is actually a blanket name for several EFAs, however. In fact, there are eight EFAs and the more included in a brand of fish oil capsules, the better.
The most common language found on the labels of fish oil capsules includes EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid). While these EFAs are important, they work best in synergy with the remaining members of the omega-3 family. So, some additional "cousins" to look for in fish oil capsules include EPA (eicosapentaenoic acid), SDA (stearidonic acid), as well as ETA, ETA-3, and HPA. Keep in mind that the total concentration of each should add up to the total amount of fish oil in the product. In addition, be aware that fish oil capsules that simply list "omega-3" as the source, then the EFAs are actually obtained from flax seeds and aren’t absorbed as well by the body.
Just as there are certain things to look for when purchasing fish oil capsules, there are also a few things that shouldn’t be on the label. For one thing, the product should state what kind of fish the oils are obtained from. So, if the label reads "marine lipids" or just "fish oils," take this as a sign that the origin is unknown or questionable. In addition, knowing the species allows for a check against the U.S. Environmental Protection Agency’s list of toxic fish to ensure the source is suitable for human consumption.
Other ingredients that are considered undesirable to be included in fish oil capsules are omega-6 and omega-9. While these are also beneficial, too much of a good thing can be bad. In fact, these EFAs can interfere with the efficiency of omega-3 since the typical American diet is already too high in omega-6. Supplementing with more will only further promote an imbalance between the essential fatty acids needed by the body for optimum performance.