Fish oil is oil derived from the tissues of oily fish. This oil naturally contains the Omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Fish oil is now recommended for a healthy diet. It is beneficial to eat fish once a week (or more) but care must be taken to avoid the fish species which contain the toxin mercury or other contaminants such as Chlordane. The list of fish includes: Largemouth Bass, Sturgeon, and others such as Shark, Swordfish, King Mackerel, and Tilefish. Note that these species are often predators, which can accumulate toxic substances due to their position at the top of the food chain.
People who dislike fish, or find it hard to fit it into their normal routine, sometimes take fish oil supplements. They are available in liquid or tablet form, although capsules are more common, and there is some debate about which form is best. An advantage of tablets and capsules is that they may reduce the chance of fishy reflux (burping and having to taste fish), although some people report this problem with tablets as well.
Most experts recommend consuming fish rather than taking fish oil supplements, if possible, because supplements may lack many important nutrients found in fish.
Benefits of fish oil
Some experts believe that taking fish oil (in any form) can help regulate cholesterol in the body. This is because of the high levels of Omega 3, specifically the effects of the EPA and DHA constituents on Peroxisome proliferator-activated receptor alpha (PPARa), whose benefits include not only reduction of cholesterol, but also anti-imflammatory properties and positive effects on body composition. However, it should be noted that the preferred source of Omega 3 should be from the fish's body, not the liver. The liver of fish and many animals, such as seals and whales, contains, besides Omega-3, the active form of Vitamin A, such as in cod liver oil. At high levels, this form of the vitamin can be dangerous. This proved fatal to early explorers to the land of the Inuit. They were given raw liver by the natives, which contained a toxic overdose of Vitamin A for the white explorers; however, the same amount was harmless to the Inuit, who had no other source of Vitamin A except animal livers.
The American Heart Association recommends the consumption of 1g of fish oil daily, preferably by eating fish, for patients with coronary heart disease.
According to a study from Louisiana State University in September 2005, fish oil may help protect the brain from cognitive problems associated with Alzheimer's disease.