Essential Fatty Acids and Mental Health
Excess consumption of fat is one of the major causes of disease and premature death in modern societies. It is intimately associated with the current epidemic levels of cardiovascular disease, stroke, diabetes, and cancer of the breast, colon, and prostate. Though over-consumption of fats clearly presents us with serious health risks, certain types of fat are actually essential for maintaining optimum health. The proper diet for brain health needs quality of essential fatty acids.
The brain and the myelin sheath (that protects the neurons) are about 75% fat. If the brain doesn't get adequate essential fatty acids, it can't function properly. Essential fatty acids bring important nutrients into cells and keep harmful toxins out. In addition, essential fatty acids produce chemicals in the body that cause a healthy inflammatory response and maintain dilation of blood vessels.
There are two main subtypes of fatty acids; the omega-3 and omega-6 fatty acids. Research has suggested that essential fatty acids can help people with attention disorders, all types of depression, schizophrenia, and neurological disorders like Alzheimer's disease and Parkinson's.
Diets high in omega-3 fatty acids, found in deep-water fish, are associated with a decreased incidence of depression and suicide. Depression has been linked to omega-3 deficiency.
Omega-3s are polyunsaturated fatty acids (PUFAs) including eicosapentaenoic acid (EPA) and docosahexaenioc acid (DHA). Research has shown that EPA affects blood flow, hormones and the immune system, which in turn affects the brain. DHA is associated with the membranes of ion channels in the brain, making it easier for them to change shape and transit electrical signals. Fish oil PUFAs include eicosapentaenoic acid (EPA) and docosahexaenioc acid (DHA).
Numerous observational studies and uncontrolled trials have reported the benefits of fish oils and omega-3 fatty acids DHA and EPA may be particularly protective against depression. Depression is 60 times more common in New Zealand than in Japan, where the Japanese get far more omega-3 from these types of cold-water fish, which include bluefish, halibut, salmon, and tuna. Omega-3 is also found in nuts, whole grains, beans, and seeds
A 2007 study from Ohio State University suggested that optimizing the ratio of omega-3 to omega-6 in the diet can alleviate the symptoms of depression. The investigators took blood samples from 43 older adults (average age 67), calculated PUFA levels, and established that people with high ratios of omega-6 to omega-3 were more likely to suffer from depression. Omega-6 essential fatty acids are found in a variety of oils including borage oil, evening primrose flax, hemp, safflower, sesame, and soybean.
Some studies have suggested that essential acids may decrease the risk of suicide. Investigators in one study found low levels of DHA and a high ratio of omega-6 fatty acids to omega-3 fatty acids were associated with an increased risk of suicide in people with depression.
A number of studies have indicated that depressed people have lower omega-3 fatty acid levels than people who are not depressed. Moreover, low levels of EPA have correlated with increased severity of depression. Research has shown supplementation of EPA can be beneficial in the treatment of depression when administered alone.
A 2007 study at Haukeland University Hospital in Norway found that cod liver oil may reduce the incidence of depression for many people. The prevalence of depressive symptoms was 29% lower in regular cod liver oil users than the rest of the population.
Since dietary sources of PUFAs, such as cold-water fish, can be difficult for some people to get enough of, many people also take fish oil supplements. This is not a bad way to get some essential fatty acids, but it is important that the fish oil be what is called "ultra pure." This class of fish oil supplements is typically tested for environmental contaminants, such as dioxins and furans, dioxin-like PCBs, PCBs, and heavy metals.
Kiecolt-Glaser JK, Belury MA, Porter K, Beversdorf DQ, Lemeshow S, Glaser R. Depressive symptoms, omega-6:omega-3 fatty acids, and inflammation in older adults. Psychosomatic Medicine 2007 Apr;69(3): 217-24. doi:10.1097/?PSY.0b013e3180313a45
Raeder B, Steen V, Vollset E, Bjelland I. Associations between cod liver oil use and symptoms of depression: The Hordaland Health Study. Journal of Affective Disorders 2007;101(1-3): 245-9. doi:10.1016/j.jad.2006.11.006
Sublette ME, Hibbeln JR, Galfalvy H, Oquendo MA, Mann JJ. Omega-3 polyunsaturated essential fatty acid status as a predictor of future suicide risk. American Journal of Psychiatry 2006 Jun;163(6): 1100-2. doi:10.1176/appi.ajp.163.6.1100