The study, published this week in the Journal of Clinical Psychiatry, looked back at the medical records of 800 U.S. servicemen and women who took their own lives between 2002 and 2008, and compared them with the records of 800 service personnel -- matched for age, gender and rank -- who had no history of suicide attempts.
Men whose records showed they had low levels of DHA in their blood were 62% more likely to have been suicide victims than those with the highest levels.
The study suggests that low DHA levels were an even stronger predictor of suicide than a far-better-recognized risk factor among military personnel: whether the service member reported having had direct exposure to allied troops that had been killed or wounded.
Suicides among U.S. military personnel, particularly Army soldiers and Marines who have served in Iraq and Afghanistan, have risen steadily since 2001 and reached a crisis point in 2008, when more than 20 of every 100,000 servicemen and women --roughly twice the national average -- took their own lives. Between 2005 and 2009, 1,100 U.S. servicemen and women took their own lives, and in 2010, the Defense Department said 295 active-duty military personnel committed suicide.
The spate of suicides -- in a population that traditionally has had lower suicide rates than their civilian counterparts -- has stirred deep concern within the military. Last year, a Defense Department task force called for better suicide-prevention programs, wider use of community expertise in suicide prevention and efforts to destigmatize help-seeking behaviors by U.S. service personnel. The task force also called for more research that could help identify those at greatest risk of attempting suicide and determine how best to help them.
This study, conducted by researchers from the Uniformed Services University of Health Sciences, the National Institute of Alcohol and Alcohol Abuse, may help identify a simple fix for service members going into harm's way: supplementation with the highly unsaturated fatty acid DHA, which is not made by the body but comes from foods such as fatty fish, as well as eggs and dairy products that have supplemented with DHA. The study's review of 1,600 medical records found that U.S. service personnel generally have low levels of DHA in their blood.
The DHA found in Omega-3 fatty acids appears to play a key role in brain function, and supplementation with the fatty acid appears to have wide-ranging psychiatric benefits. Supplemental DHA has been found to enhance the effectiveness of antidepressants, to improve symptoms of attention deficit disorder and forestall the initial onset of psychosis in people at risk for schizophrenia. (A recent study of pregnant women found, however, that DHA supplementation for pregnant women did not lower their risk of post-partum depression or make their babies smarter.) The authors of the current study stress that its design has limitations and that more research is needed before the role of DHA levels in suicide is clear.