Omega-3 fatty acids are considered essential fatty acids: They are necessary for human health but the body can't make them; you have to get them through food. Omega-3 fatty acids can be found in fish, such as salmon, tuna, and halibut, other seafood including algae and krill, some plants, and nut oils. Also known as polyunsaturated fatty acids (PUFAs), omega-3 fatty acids play a crucial role in brain function as well as normal growth and development. They have also become popular because they may reduce the risk of heart disease. The American Heart Association recommends eating fish (particularly fatty fish such as mackerel, lake trout, herring, sardines, albacore tuna, and salmon) at least 2 times a week.
According to Alexander B. Niculescu, M.D., Ph.D., associate professor of psychiatry and the lead author of the study, the fatty acid DHA, which is one of the main active ingredients in fish oil, "normalized their behavior".
"The mice that were given DHA normalized their behavior, they are not depressed and when subjected to stress, they do not become manic. When we looked into their brains, using comprehensive gene expression studies, we were surprised to see that genes that are known targets of psychiatric medications were modulated and normalized by DHA."
These same mice seemed to be kinds of alcoholics also and the DHA affected this behavior too.
"These bipolar mice, like some bipolar patients, love alcohol. The mice on DHA drank much less; it curtailed their alcohol abusive behavior. We believe a diet rich in omega 3 fatty acids may help the treatment and prevention of bipolar disorder, and may help with alcoholism as well."
DHA is the most abundant omega-3 fatty acid in the brain and retina. DHA comprises 40% of the polyunsaturated fatty acids (PUFAs) in the brain and 60% of the PUFAs in the retina. Fifty percent of the weight of a neuron's plasma membrane is composed of DHA.
DHA deficiency affects normal transmission of signals across membranes in the brain. Its deficiency may speed up aging and cause various health problems, such as behavioral disorders, depression, hyperactivity, postpartum depression, stroke, Alzheimer's disease, Parkinson's disease, schizophrenia, cancer, and diabetes.
"There is now substantial evidence at the molecular level that omega-3 fatty acids work on the brain in ways similar to psychiatric drugs. With these biomarker findings, we can now move forward as a field and do more targeted clinical studies in humans."
Countries with the highest intake of fish in their diets are correlated with the lowest rates of depression among citizens.
Source: Translational Psychiatry