Certain fats are essential for health and are among the most powerful medicines, acting as natural painkillers and more potent antidepressants than conventional drugs. These are the omega-3 fats, and they are known to control our mental and physical health, and protect against depression, aggression, and inflammatory diseases, including heart disease and arthritis.
These essential fats benefit health so dramatically because they are turned by the body into a group of compounds called prostaglandins that seem to control just about everything, from hormonal balance to how the brain reacts and responds.
There are two families of essential fats: omega-3 and omega-6. Both of these omega-fats are needed by the body, but most people obtain enough omega-6 in their diet and not enough omega-3.
The most potent dietary source of omega-6 is called GLA, which is highly concentrated in evening primrose oil and borage oil. It can also be made in the body from sunflower and sesame seed oils.
Omega-3 fats are found in high quantities in oily fish or cod liver oil. Some omega-3 fats are also found in flaxseeds, pumpkin seeds, walnuts, and other nuts and seeds, but this oil is prone to oxidation and makes food go rancid quickly, which is why it is removed from many foods that need to have a long shelf life. This and other factors mean that many people are more deficient in omega-3 than omega-6 fatty acids.
When more omega-6 fats and less omega-3 fats are consumed, it also means the greater is the inflammatory effect of a meal. This is because omega-6 fats, found in processed foods, margarines, and more commonly used seed oils such as sunflower oil, have the ability to turn into inflammatory fats in the body. On the other hand, food sources of omega-3 fats switch off inflammation by turning into anti-inflammatory compounds in the body, which counteract disease, as proven by numerous studies.
Here are just a few research findings that highlight ways in which omega-3 oils protect health:
- Omega-3 fish and fish oil switch off inflammation (found in eczema, asthma, arthritis, colitis, etc) caused by poor diet , and fish oil supplements decrease pain and stiffness in arthritis sufferers more effectively than painkilling drugs. 
- Omega-3 supplements reverse depression more effectively than antidepressant drugs,  and fish or fish oil supplements have been consistently linked to decreasing hostility and aggression,  as well as a decreased risk of suicide. 
- Eating oiling fish and/or supplementing omega-3-rich fish oil effectively halves the risk of suffering a second heart attack, and UK doctors are now recommending that it should be prescribed to patients after a heart attack. 
These important benefits are good reasons to optimize your intake of health-promoting omega-3 fats
, while reducing your intake of processed, refined and damaged fats
Oily fish (herring, sardines, mackerel, salmon, tuna and trout) are by far the best sources of omega-3 fats, and as a bonus they are also high in protein, Vitamin E and selenium. Nuts and seeds also contain smaller amounts of this healthy fat, but in the form of ALA, which has to be converted into EPA and DHA by the body.
Supplementation is another way of boosting your intake of these essential nutrients. When buying an omega-3 supplement, look for one that provides good levels of the three forms of omega-3: EPA, DHA and DPA, and one that has been purified to remove contaminants and toxins such as heavy metals.
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-  Goldberg RJ, Katz J. A meta-analysis of the analgesic effects of omega-3 polyunsaturated fatty acid supplementation for inflammatory joint pain. Pain, 2007 May;129(1-2):210-23.
-  Lin P, Su K. A meta-analytic review of double-blind, placebo-controlled trials of antidepressant efficacy of omega-3 fatty acids. Journal of Clinical Psychiatry, 2007 Jul;68(7):1056-61.
-  Iribarren, et al. Dietary intake of n-3, n-6 fatty acids and fish: relationship with hostility in young adults - the CARDIA study. European Journal of Clinical nutrition, 2004 Jan;58(1):24-31.
-  Hallahan B, et al. Omega-3 fatty acid supplementation in patients with recurrent self-harm: single-centre double-blind randomized controlled trial. British Journal of Psychiatry, 2007 Feb;190:118-22.
-  No authors listed. Dietary supplementation with n-3 polyunsaturated fatty acids and Vitamin E after myocardial infarction: results of the GISSI-Prevenzione trial. Lancet, 1999 Aug 7;354(9177):447-55.