Serum alpha-linolenic and linoleic acids are inversely associated with depressive symptoms in adults

Abstract

Summary Background & aims Fatty acid composition in diet and serum has been linked to depression, but the evidence on this issue is limited among Japanese, who consume large amounts of fish rich in n-3 polyunsaturated fatty acids. We examined the association between fatty acid composition in serum and depressive symptoms in Japanese men and women. Methods The subjects were 496 participants aged 21–67 years in a cross-sectional study. Depressive symptoms were assessed using the Center for Epidemiologic Studies Depression (CES-D) scale. Free, cholesterol ester, and phospholipid fatty acids in serum were measured by gas–liquid chromatography. Multiple logistic regression was used to assess the association between serum fatty acid and depressive symptoms. Results A higher free alpha-linolenic acid level was marginally significantly associated with a decreased prevalence of depressive symptoms (CES-D ≥ 16) (P for trend = 0.07). When a cut-off of CES-D ≥ 19 was used, the association was strengthened; the multivariable-adjusted odds ratios (95% confidence interval) of depressive symptoms for the lowest through highest tertile of alpha-linolenic acid levels were 1.00 (reference), 0.49 (0.29–0.84), and 0.47 (0.26–0.83), respectively (P for trend = 0.007). A higher n-6 PUFA in cholesterol esters and free linoleic acid were also significantly associated with a decreased prevalence of depressive symptoms (CES-D ≥ 19) (P for trend = 0.03 and 0.048, respectively). The other polyunsaturated fatty acids including marine-derived n-3 PUFA were not associated with depressive symptoms. Conclusions Fatty acid composition with high levels of serum alpha-linolenic and linoleic acids might be protectively associated with depressive symptoms in Japanese adults.