Fish oil is an animal source of DHA and EPA omega-3 polyunsaturated fats. It is found most abundantly in fatty fish such as salmon and tuna, or as pill or oil supplement. Fish oil is widely known and used in the management of cardiovascular disease. However, studies have revealed it may also be used for many other brain functions, including the management of mood disorders and depression.
Omega-3s Role in the Body
Omega-3s are essential fats. The body cannot produce them on its own. Food sources of Omega-3 include fatty fish such as salmon, tuna and mackerel; walnuts; and flaxseed and canola oil. Omega-3 acids are also widely available in supplement form as either fish oil or flaxseed oil. The National Institute of Health identifies a main function of omega-3 as helping reduce pain and swelling and to improve brain and nerve functions.
Fish Oil and Depression -- The Evidence
There is debate among researchers that fish oil is effective in treating depression. Dr. Daniel Hall-Flavin of the Mayo Clinic believes that fish oil can be used to treat symptoms of depression and anxiety. In a 2009 issue of "Neurosignals," a study suggested that fish oil may treat symptoms of depression along with medication. A review in "Age and Nutrition" states there is a inverse relationship between the incidence of seasonal depression and the amount of Omega-3's present in the an individual's blood plasma. However, Dr. Michael Maes, in "Neuroendocrinology Letters," concludes that DHA Omega-3 in fish oil can interfere with the function of regular anti-depressant drugs, but EPA Omega-3 does not intere with the function of antidepressants.
The appropriate dosage for treating depression and anxiety is inconclusive in research. According to the National Institute of Health, the dose for fish oil when treating depression is 9.3 g or 9,300 mg per day. This is far beyond the recommended dose of 1 to 4 g for cardiovascular disease. One study found that doses between 200 mg and 9 g is effective for treatment. However, Dr. Hall-Flavin recommends just 100 to 300 mg daily for treatment of depression and anxiety, although he stated that more research is needed to determine ideal doses.
High doses of Omega-3 fatty acids can have potential risks and interactions with medication. Do not begin a fish oil regimen without consulting a physician first. According to the NIH, there is a risk of bleeding from consuming more than 3 g of Omega-3 per day. Fish oil also may increase the effects of high blood pressure medications and lower blood pressure to severe levels. Birth control and Orlistat medications for weight loss may inhibit absorption of fish oil.
- National Library of Health: Fish Oil
- "Neurosignals"; Biological Mechanism of Antidepressant Effect of Omega-3 Fatty Acids: How Does Fish Oil Act as 'Mind-Body Interface'?; Kuan-Pin Su; February 2009
- "Neuroendocrinology Letters"; Why fish oils may not always be adequate treatments for depression or other inflammatory illnesses: docosahexaenoic acid, an omega-3 polyunsaturated fatty acid, induces a Th-1-like immune response; Michael Maes; November 2007
- "Age and Nutrition"; Dietary omega-3 Fatty acids and psychiatry: mood, behaviour, stress, depression, dementia and aging; JM Bourrne; April 2005.