Fish oil is generally derived from the processing of the flesh or the liver of oily fish. Fish oil is most commonly used as a health supplement for its concentrations of Omega-3 fatty acids, most notably EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid). Fish species used in the manufacture of fish oil concentrate include tuna, salmon, swordfish, mackerel, anchovy, herring and sardine. Fish oil is also processed from the livers of codfish and sharks. Oily fish do not actually produce Omega-3 acids themselves; rather they are acquired through the consumption of algae or plankton.
Omega-3 fatty acids can also be obtained by consumption of oily fish as a part of a regular diet. It should be noted that fish that have high concentrations of fish oil are also more likely to carry higher levels of toxins such as mercury and PCBs due to their position in the food chain. For this reason it is often recommended that consumption of these fish be restricted.
Fish oil is processed from whole fish in a multi-stage process. The oil bearing fish is first cut into pieces and then cooked. A centrifugal system is used to separate the solid matter from the liquid. The liquid component, sometimes referred to as press liquor, is further separated into its two constituents: water and fish oil. The fish oil is then distilled and purified. Fish oil as a supplement for human consumption is typically packaged in a soft gel capsule, which regulates dose and absorption by the body.
Fish oil is used as a health supplement for its concentrations of Omega-3 fatty acids. Omega-3 acids have been frequently touted as offering benefits to a wide range of disorders including: cardiovascular, mental health and neuro-development, as well a skin ailments and high blood pressure.
Some studies have suggested that consumption of fish oil, as a supplement or from regular diet, can reduce the risk of heart disease and stroke. Additionally, fish oil is used to lower blood pressure in patients suffering from hypertension.
Many studies have been conducted regarding the effects of fish oil on depression, psychosis and violent behavior. Some of these studies have indicated that higher levels of fish oil, or administration of fish oil supplements can reduce levels of depression and violent tendencies. Furthermore, early research suggests that schizophrenia onset may be reduced in high risk individuals.
Pregnancy and Infancy
It has been shown that babies born from mothers taking fish oil supplements during pregnancy and during breast feeding have a higher level of psycho motor development and visual acuity at an earlier age than babies of mothers not taking the supplements. Supplements are especially beneficial for pregnant mothers as they avoid the risk associated with consuming fish with potentially high levels of mercury and PCBs.
In addition to the above, fish oil has been linked to positive results in the treatment of glaucoma, macular degeneration, psoriasis, asthma, and kidney disease. Fish oil is also touted as effective for pain relief and as an anti-inflammatory.
Efficiency and Side Effects
While many studies have indicated that fish oil, and specifically Omega-3 fatty acid, has a measurable benefit to a variety of disorders, there have been many more studies which show no direct health benefit from taking fish oil as a supplement. More research needs to be conducted to determine the exact benefits of Omega-3 fatty acids.
The generally accepted dosage of fish oil as a supplement is 1000mg (300mg – 500mg each of EPA and DHA) and no more than 3000mg. Remember that fish oil is also acquired through a regular diet, with some species of fish (notably; herring, mackerel and salmon) containing one to two grams of naturally occurring fish oil per serving.
Side effects of fish oil when taken as indicated are negligible. Daily doses in excess of 3000mg of fish oil increase the risk of bleeding and stroke. Further concerns associated with fish oil supplements are the possibility of contamination with toxins and spoilage of the product.