Fish oil is oil that is extracted from the tissues of oily fish. It contains nutrients that have several health benefits, such as the omega-3 components EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid). The fish that the oily extract comes from do not actually produce the oil naturally. It is a factor of their diets where they consume algae, and also when they consume other fish that have accumulated the omega-3 fatty acids.
The omega-3 health benefits include preventing heart disease and for treating hypertriglyceridemia. It is also being used in studies to evaluate treatment and prevention of cancer, anxiety, and depression. Results are still unverified but are still hopeful.
It sounds like some of the more predatory species of fish, including sharks and swordfish, would be the best in producing omega-3, but their nature as top predators also means they accumulate a lot of toxic substances from their prey as well, such as dioxin and mercury. Species further down the food chain product more consumable amounts of omega-3. The more common fish used for omega-3 products are herring, sardines, mackerel, salmon, halibut, and tuna.
Fish oil is a commonly used dietary supplement. Worldwide sales are well over a billion dollars annually. Quality of the fish oil is always a concern, with biotoxin contamination and inaccurate listing of EPA and DHA levels. But reviews of potential dangers have indicated that taking fish-oil is low risk and clinically insignificant.
How much should you take? A good baseline measurement is up to 3000mg of omega-3 per day. Consuming much more does not provide additional health benefits. But for the amount you consume, the health benefits realized can be significant.
What about the fishy taste? Many omega-3 supplements are available in a soft capsule. You’d think that would leave any fishy after-taste behind. But if you’ve ever taken those omega-3 capsules, you’ve surely experienced the “fishy burp”. It can be an unpleasant experience that lasts several hours after consumption where your regular burps feel like they are more frequent, and are accompanied by a fish-like sensation. If you are taking omega-3 as a health supplement and are not a fan of seafood to begin with, this might not be very pleasant. However there are several brands of omega-3 on the market that are advertised as “no fishy aftertaste”. They have the same health benefits as the soft-gel capsules but are easier on your digestive system.