Background: Epidemiologic studies show that low fish intake is a risk factor of suicidality; however, there are no case-control studies investigating suicide attempt risk and tissue n-3 fatty acid levels.
Methods: We recruited 100 suicide-attempt cases and another 100 control patients injured by accidents who were admitted to three hospitals affiliated with Dalian Medical University in Dalian, China. Case and control subjects were matched for age, gender, and smoking status. Those who were inebriated at the time of hospitalization were excluded. Blood was sampled immediately after admission to a hospital. Washed red blood cells (RBCs) were obtained, and the fatty acid composition of the total RBC phospholipid fraction was analyzed by gas chromatography.
Results: Eicosapentaenoic acid (EPA) levels in RBC in the case subjects were significantly lower than those of the control subjects (.74 +/-.52% vs. 1.06 +/-.62%, p <.0001). When the highest and lowest quartiles of EPA in RBC were compared, the odds ratios of suicide attempt was.12 in the highest quartile (95% confidence interval:.04-.36, p for trend =.0001) after adjustment for possible confounding factors
Conclusions: Our findings suggest that low n-3 fatty acid levels in tissues were a risk factor of suicide attempt. Further studies including intervention with fish oil are warranted.