Fish oil is derived from a variety of oily fish, and contain the Omega-3 fatty acids, Eicosapentaenoic acid (EPA) and Docosahexaenoic acid (DHA), and are known to reduce inflammation in the body (anti-inflammatory) and have other health benefits.
EFAs are considered “essential” because humans need them for proper health—and much like certain vitamins and minerals we cannot produce them on our own; therefore, they need to be consumed these fats through diet or supplementation.
[NOTE: In the supplement world, often the terms Fish Oils, Omega-3, and Essential Fatty Acids (EFAs) are used either interchangeably, or to refer to the same supplements]
The Omega-3 fatty acids in fish oil are thought to be beneficial in treating a wide variety of ailments due to the their anti-inflammatory properties. It is worth explaining that the body can become “inflamed” for a variety of reasons not generally understood. Certainly injuries and infections produce inflammation in the human body, but other common causes of inflammation include sun exposures, exercise, stress, etc. Equally important, human cells can be damaged for a variety of reasons and illnesses, and Fish Oil aid in the repair process of those cells.
For this reasons, as well as the extensive research conducted on Fish Oils, most health organizations and Nutra highly recommend that adults include Fish Oils in their daily supplement and diet. Naturally, the most common source of Fish Oils are the consumption of fish themselves, which is often absent or under-consumed particularly in American (and Western) diets.
There has been extensive, documented research has documented the health benefits of Fish Oils and EFA, which include heart health, brain and cognitive function, joint mobility, neurological pain, general pain relief, eye health, pregnancy and lactation, healthy skin and hair, improved immune system response, psoriasis and others.
As with all supplement products, not all are created equal. The US market for Fish Oils is currently over $1 billion per year, and there are literally hundreds of brands on the market. This link provides a review and laboratory testing of 30 Fish Oil products.