Higher polyunsaturated fat consumption may reduce suicide risk

An increase in the consumption of foods rich in polyunsaturated fats may decrease suicide risk, according to a study results featuring a large military personnel sample published in Journal of Clinical Psychiatry.

“[Fatty acids] are implicated in biological systems associated with depression and suicide, including neurotransmitters, cell membranes and the immune system,” Arthur Thomas Ryan, PhD, of the Veterans Affairs VISN 5 Mental Illness Research, Education and Clinical Center in Maryland, and colleagues wrote. “Individuals with mental illness have altered levels of various [fatty acids] as compared with healthy controls. The levels of several [fatty acids], particularly n-3 [fatty acids], have also been associated with suicidal behavior; however, the relationship between various [fatty acids] and suicidal behavior has been somewhat inconsistent across studies.”

The investigators aimed to assess whether having distinctive fatty acid profiles was linked to observed fatty acid levels among a sample of 800 U.S. military members who died by suicide between 2002 and 2008 and 800 demographically matched living controls, as well as whether an association existed between those latent classes and suicide and mental health diagnoses. They collected participants’ serum samples from a large military serum repository, assayed them for 22 different fatty acids and conducted a latent class cluster analysis using values of six fatty acids previously individually linked to suicide. Following identification of the latent classes, the researchers then compared them in terms of suicide decedent proportion, demographic variables, estimated fatty acid enzyme activity, diagnoses and mental health care usage.

Findings demonstrated that a six-latent class solution best characterized the dataset. The researchers noted a lower likelihood for suicide decedents to belong to two of the classes and a higher likelihood for them to belong to three of the classes. Further, they observed a difference on nine fatty acids and on estimated indices of activity for three fatty acid enzymes between the low- and high-decedent classes. These were 14:0, 24:0, 18:1 n-9, 24:1 n-9, 22:5 n-3, 22:6 n-3, 20:2 n-6, 20:4 n-6, 22:5 n-6, elongation of very long chain fatty acids protein 1 (ELOVL1), ELOVL6 and Delta9 desaturase. They also noted a consistency between the fatty acid profiles of the latent classes and biological abnormalities previously linked to suicidal behavior.

“These findings suggest the possibility of [fatty acid]-related biotypes with suicide-relevant biological alterations,” Ryan and colleagues wrote. “The existence of research showing that the effects of [fatty acid] supplementation may depend on the genetic makeup of an individual further suggests the possibility that some individuals might be more or less likely to benefit from [fatty acid] supplementation. Future research is needed to replicate our findings and simultaneously measure biological alterations (eg, inflammation) that might be associated with the [fatty acid] profiles of our [latent class cluster analysis] identified classes.”