Of the much-ballyhooed benefits of Omega-3 fish oil, none seem to garner the attention as those pertaining to conditions related to the brain. One area of great importance to researchers is depression. Depression reportedly affects some 1 in 10 people in America and has become one of the most studied mental health conditions in science today. Fish oil, specifically Omega-3 fatty acids, are polyunsaturated fats necessary for human health, but cannot be made by the body. Humans must get them from dietary sources, primarily from fish and seafood. The omega-3 fatty acids from fish oil with the most direct influence on brain development and function is DHA (docosahexaenoic acid). This has caused researchers all over the world to ask the question, could there be a link between DHA and mental health?
DHA is highly concentrated in the brain and it is concentrated in the brain right where the neurons communicate with each other and all the signals pass back and forth. DHA makes up the walls of those neurons. Your brain is actually 60 percent DHA, which is why when trying to address certain behavioral conditions or other mental health problems, scientists have long pondered the importance of adequate dietary intake of DHA.
Researchers first became interested in the connection between fish oil and mental health when they noticed that countries with the highest fish consumption had the lowest rates of depression. They also observed that mothers in England who ate very little fish during pregnancy doubled their risk of developing postpartum depression compared to women who ate fish regularly. In their endeavor to find out why, scientists have discovered a very interesting coloration between fish oil and the brain.
Perhaps the most telling is a recent study published in the Journal of Clinical Psychiatry. In that study, scientists from the National Institute on Alcohol Abuse and Alcoholism (NIAAA) led by CAPT. Joseph R. Hibbeln, M.D., in association with researchers at the Uniformed Services University of the Health Sciences (USUHS) in Bethesda, Md., looked at a sample of suicide deaths among U.S. military personnel on active duty between 2002 and 2008. The researchers compared blood levels of omega-3 fatty acids of 800 individuals who committed suicide with those of 800 randomly selected controls – service members who were matched with the suicide cases by age, sex, and rank. They found that all the service members who had committed suicide had extremely low omega-3 levels compared to the control group. The researchers noted that suicide risk was greatest among individuals with the lowest levels of DHA.
According to Army Col. (Dr.) Michael D. Lewis, lead author of the study.
“We were surprised to find just how low the levels of omega-3 fatty acids were in the entire sample. There still was a significant suicide risk when we stratified the population. When we compared the 1,400 samples with the lowest levels of DHA to the remaining 200, there was a 62 percent increased risk that the samples were from a documented suicide.”
U.S. Public Health Service Capt. (Dr.) Joseph Hibbeln, corresponding author, also had this to say:
“Our findings add to an extensive body of research that points to a fundamental role for DHA and other omega-3 fatty acids in protecting against mental health problems and suicide risks. For example, a previous placebo-controlled trial demonstrated that 2 grams of omega-3 fatty acids per day reduced suicidal thinking by 45 percent, along with depression and anxiety scores among individuals with recurrent self-harm. In a prior study researchers found low blood levels of DHA correlated with hyperactivity of brain regions in a pattern that closely resembles the pathology of major depression and suicide risk.”
In another study conducted At Sheffield University in England, Dr. Malcolm Peet gave omega-3 fatty acids from fish oil to 70 depressed patients who had not been helped by drugs such as Prozac. After 12 weeks, 69 percent of the patients showed marked improvement compared with 25 percent given placebos. Such results are becoming more and more common as the research continues.
Not all studies, however, have shown favorable results. In a study conducted at the Prince of Wales Hospital in Australia, a randomized double-blind placebo-controlled trial on Omega-3 fatty acids as a treatment for perinatal depression suggested there was no significant difference in depression scores between those receiving fish oil and those receiving the placebo. However, the researchers did comment that it may be unwise to interpret the results as conclusive and that further research is needed in this area to establish whether omega-3 fatty acids are an effective treatment.
While these data are promising, and give perhaps a preliminary window into what might be a contributing factor in the cause of depression, or at least a potential alternative in treating it, researchers say much larger studies are now needed to follow up on the initial success of omega-3 trials, not only in how they affect the potential for suicidal ideation and depression, but also their potential effect on other mental health issues such as schizophrenia, bipolar disorder, and violent behavior.