Suicide rates among U.S. military personnel have risen at an alarming rate in recent years. In the search for risk factors, researchers at the Uniformed Services University of the Health Sciences (USU) and the National Institute of Alcoholism and Alcohol Abuse (NIAAA) at the National Institutes of Health (NIH) recently published a study that determined that deficiencies of highly unsaturated omega 3 essential fatty acids (HUFAs)—especially docosahexaenoic acid (DHA)—could be associated with increased risk of suicide death among a large random sample of active-duty U.S. military.
 
Published in a recent online installment of the Journal of Clinical Psychiatry, researchers in the retrospective, case-control study quantified serum fatty acids as a percentage of total fatty acids in 800 active U.S. military suicide deaths between 2002 and 2008. They then carefully matched a group of 800 control subjects based on age, sex, rank and year of incident to test the hypothesis that omega 3 levels (DHA in particular) would be lower in the suicides as compared to their matched controls. 
 
“Omega 3s and DHA in particular are concentrated in the brain and are essential for brain development and ongoing health,” Army Col. (Dr.) Michael D. Lewis, lead author on the study and assistant professor in the Department of Preventive Medicine and Biometrics at the USU told Nutraceuticals World. “Previous studies have associated low levels of omega 3 fats or low dietary intake of seafood, with suicide, thoughts of suicide and depression. Many, but not all, treatment studies also have reported mental health benefits of supplemental DHA, including reduced anxiety, depression and risk of psychosis.”
 
After analyzing the data, researchers found that the U.S. military population had a very low and narrow range of HUFAs. Furthermore, the risk of suicide death was 14% higher per suicide of lower DHA percentage in adjusted logistic regressions. Among men, risk of suicide death was 62% greater with low serum DHA status. Risk of suicide death was 52% greater in those who reported having seen wounded, dead or killed coalition personnel.
 
“We were surprised to find just how low the levels of omega 3 fatty acids were in the entire sample,” said Dr. Lewis. “There still was a significant suicide risk when we stratified the population. When we compared the 1400 samples with the lowest levels of DHA to the remaining 200, there was a 62% increased risk that the samples were from a documented suicide. We need to continue to evaluate these results with a well-designed interventional study, but this represents a potential simple nutritional intervention that warrants further investigation.”

“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,” said U.S. Public Health Service Capt. (Dr.) Joseph Hibbeln, acting chief of the Section of Nutritional Neurosciences in NIAAA’s Laboratory of Membrane Biochemistry and Biophysics and corresponding author. “For example, a previous placebo-controlled trial demonstrated that 2 grams of omega 3 fatty acids per day reduced suicidal thinking by 45%, along with depression and anxiety scores among individuals with recurrent self-harm.”
 
He added that in a prior study they 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. “Depression has an effect on the prefrontal cortex that can be influenced with omega 3s,” concurred Dr. Lewis. “Biochemically, omega 3s effect the serotonergic pathways and levels.”

The researchers were quick to point out that although their data suggested that low serum DHA may be a risk factor for suicide, well-designed intervention trials are needed to evaluate causality. “Concerning a follow-up interventional study, that is what we are proposing to the military and it is being strongly considered. However, conducting randomized clinical trials are not cheap or easy to do,” said Dr. Lewis. “It will take serious time and resources to do scientifically sound studies but that is the direction we recommend to best move from the association we found in our study to explore more deeply and scientifically the probability of a causal relationship.”
 
In the meantime, the military—the Army most specifically—is taking the results of this latest study very seriously. “The Health Promotion & Risk Reduction Task Force convened by the Vice Chief of Staff of the Army, General Chiarelli, has been working diligently to collate the best science, scientists, thinkers, and operational personnel to assess the current knowledge status and find the best ways forward in the areas of research and program implementation. Suicide is always multi-factorial and omega 3 status is one easily measurable factor that can be quickly influenced,” Dr. Lewis commented. “The Task Force now recognizes that nutrition can and should play a major factor in overall health and potentially in suicide risk reduction. However, there is no panacea for suicide. We only hope that our research efforts eventually will contribute to a substantial lowering of the rates of suicide now seen in the military with implications for the general population as well.”