No abstract

a b s t r a c tBackground: Although fatty acid composition in serum and desaturase activity, which alters serum fatty acid composition, has been associated with C-reactive protein (CRP) concentration in Western populations, no study has been carried out in non-Western populations. We examined the association of serum fatty acids and estimated desaturase activity with CRP concentrations in Japanese men and women. Methods: Subjects were 489 Japanese municipal employees aged 21-67 years who participated in a survey at the time of a periodic health check-up. Serum high-sensitivity CRP concentrations were measured using the latex agglutination nephelometry method. Fatty acid composition was measured in serum cholesteryl esters and desaturase activities by fatty acid product-to-precursor ratios. Relationships were assessed using multiple regression. Results: Serum CRP concentration was positively associated with palmitic acid (P for trend = 0.002) and inversely with alpha-linolenic acid (P for trend = 0.01) in men, and positively with dihomogamma-linolenic acid (P for trend in men or women = 0.01) and inversely with delta-5-desaturase (20:4n-6/20:3n-6) (P for trend in men and women = 0.05 and 0.002, respectively) in men and women. Conclusions: Low-grade inflammation may be associated with a serum fatty acid pattern of high palmitic acid or low alpha-linolenic acid in men, and of high dihomo-gamma-linolenic acid or low delta-5-desaturase in both sexes.

BackgroundSupplementation studies have suggested a role of n-3 polyunsaturated fatty acids (PUFAs) in homocysteine metabolism, but the evidence is limited and inconsistent among studies that measured blood levels of n-3 and n-6 PUFAs. We examined the association between blood levels of PUFAs and homocysteine in Japanese men and women.MethodsThe subjects were 496 employees (290 men and 206 women) of 2 municipal offices in Japan. Fatty acid composition in serum phospholipids and cholesterol ester (CE) was measured using gas–liquid chromatography. Multiple regression was used to calculate means of homocysteine concentrations according to PUFA tertile with adjustment for potential confounders.ResultsSerum homocysteine concentration decreased with increasing levels of total n-3 PUFA, eicosapentaenoic acid and docosahexaenoic acid (DHA) in serum phospholipids and CE with adjustment for age, sex and workplace. However, only DHA in serum phospholipids remained statistically significant after additional adjustment for other potential confounders including serum folate (P-trend = 0.04). N-6 PUFAs were not significantly associated with homocysteine concentrations.ConclusionsHigher proportion of DHA in serum phospholipids may be associated with lower homocysteine concentrations in Japanese men and women.

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 21e67 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 gaseliquid 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 ¼ 0.07). When a cutoff 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 (0.29e0.84), and 0.47 (0.26e0.83), respectively (P for trend ¼ 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 ¼ 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.