Association between habitual tryptophan intake and depressive symptoms in young and middle-aged women

• Published in: Journal of affective disorders 2018-04, Vol.231, p.44-50
• Main Authors: Suga, Hitomi, Asakura, Keiko, Kobayashi, Satomi, Nojima, Masanori, Sasaki, Satoshi
• Format: Article
• Language: English
• Subjects: Cross-sectional; Depressive symptoms; Diet; Tryptophan; Women
• ISSN: 0165-0327; 1573-2517
• DOI: 10.1016/j.jad.2018.01.029

The intake of tryptophan, the precursor of serotonin, is assumed to affect serotonin availability and depression onset. Nevertheless, a definitive relationship between dietary tryptophan intake and depressive symptoms has not been established. We examined the association between tryptophan intake and depressive symptoms screened in a group of 4272 first-year female dietetic students and 3651 their mothers. Dietary tryptophan intake during the preceding month was assessed with a validated, self-administered diet history questionnaire. Depressive symptoms were assessed with the Center for Epidemiologic Studies Depression Scale (CES-D) using two cutoff scores: CES-D score ≥ 16 and CES-D score ≥ 19 (the optimal cutoff score for Japanese people). The multivariate adjusted prevalence ratio (PR) and 95% confidence interval (CI) for depressive symptoms were calculated using Poisson regression analysis. The prevalence of depressive symptoms (CES-D score ≥ 16) was 50.0% for young women and 26.5% for middle-aged women. The adjusted PR (95% CI) for depressive symptoms in the highest versus lowest quintile of tryptophan intake was 0.84 (0.75, 0.93) in young women (P for trend