A Pilot Study of the Relationship between Diet and Mental Health in Community Dwelling Japanese Women

Background and Objectives: Diet is closely linked to mental health. The aim of this study was to explore the link between diet and mental health in community dwelling Japanese women. Materials and Methods: A total of 89 community dwelling Japanese women, aged 66.8 ± 7.6 years, were enrolled in this cross-sectional study. Diet surveys were evaluated using the brief-type self-administered diet history questionnaire (BDHQ) and mental health was evaluated using the general health questionnaire-12 (GHQ) and clinical parameters. Results: The mean energy intake was 1806 ± 570 kcal and the GHQ score was 1.0 ± 1.4. Among nutrients, the n-6/n-3 fatty acid ratio was significantly correlated with the GHQ score (r = 0.269, p = 0.011), and some micronutrients and vitamins were weakly or negatively correlated with the GHQ score. Among the food groups, fish and shellfish were negatively correlated with the GHQ scores. Multiple regression analysis demonstrated that the n-6/n-3 fatty acid ratio was the determinant factor for the GHQ score, even after adjusting for confounding factors. Conclusions: These results suggest that a proper diet to reduce the n-6/n-3 fatty acid ratio may improve mental health in community dwelling Japanese women.