Dietary intake of omega-3 fatty acids and risk of depressive symptoms in adolescents

Background: Previous randomized controlled trials have demonstrated that omega-3 polyunsaturated fatty acids (n-3 PUFA) are beneficial in reducing symptoms of depression. However, there is limited evidence regarding the influence of dietary n-3 PUFA intake on mood in adolescents drawn from population studies. Objective: In the present investigation, we examined the relationship between dietary n-3 PUFA intake on depression symptomatology in a large prospective pregnancy cohort followed for 17 years. Methods: Adolescents enrolled in the Western Australian Pregnancy Cohort (Raine) Study completed a Food Frequency Questionnaire to assess dietary fatty acid intake, as well as other dietary factors at age 14 and a fasting blood sample was taken. Participants also completed the Beck Depression Inventory for Youth (BDI-Y) at age 14 (N = 1,407) and at age 17 (N = 995). Results: An inverse relationship was observed between intake of both saturated fat and of n-3 PUFA at age 14 and BDI-Y scores at both 14 and 17 years of age. However, after adjusting for energy (kJ) intake and other lifestyle confounders, the relationships were no longer significant. Conclusions: Associations previously reported between n3 PUFA and depressive symptoms may be due to collinearity with other dietary and lifestyle factors. © 2011 Wiley-Liss, Inc.