Daily dietary isoflavone intake in relation to lowered risk of depressive symptoms among men

Abstract

BackgroundThe relationship between isoflavone intake and depressive symptoms has been examined among premenopausal and postmenopausal women but not among men. Therefore, we investigated whether isoflavone intake is associated with depressive symptoms among men. MethodsThis cross-sectional study was conducted between 2008 and 2011. A total of 1335 Japanese men aged 19–83 participated in the present study. Isoflavone intake was measured using the Brief-type Self-administered Diet History Questionnaire (BDHQ). Depressive symptoms were assessed using the Self-rating Depression Scale (SDS), and two cut-off values (i.e., 40 and 50) were used. Multiple logistic regression analysis was conducted to examine the association between isoflavone intake and depressive symptoms. ResultsWhen the cut-off value for SDS was specified as 40, the odds ratios (ORs) for depressive symptoms were higher for the categories that were characterized by high rather than low levels of isoflavone intake in the crude model (p = 0.002). This association remained unchanged (p = 0.029) when potential cofounds were controlled for in Model 3. Multivariate linear regression analysis also showed a significant inverse association between isoflavone intake and SDS scores (p = 0.027; final adjusted model). LimitationsCross-sectional study is difficult to draw any conclusions about causality ConclusionsThe findings suggest that a high level of dietary isoflavone intake is associated with a lower prevalence of depressive symptoms among men. Therefore, isoflavone intake may have a beneficial effect on men's mental health.