Relationship of Dietary Folate Intake, Serum Folate and Homocysteine with Depression In Young Women

Objective: Folate deficiencies may be linked to depression. However, almost all published studies have been conducted with the elderly or persons with dementia disease; it is currently unknown how folate affects reproductive-aged women's mental health. The purpose of this study is to evaluate the association between folate and depressive symptoms in young women.

Design: A cross-sectional study.

Setting: The study was conducted in Japan, 2009.

Patients/Participants: A total of 141 young Japanese women aged 18-28 years were participated in this study.

Methods: A Japanese version of the Center for Epidemiologic Studies Depression (CES-D) scale was used to screen for depression. Dietary intake was investigated by a diet history questionnaire. Non-fasting blood samples were collected from the women to measure folate and homocysteine (Hcy) levels.

Results: In total, 63 women (44.7%) were identified having depressive symptoms (CES-D scores ≥16). The proportions of women with lower folate intake (<240 µg/d) was significantly higher in the women with CES-D score ≥ 16 than in those with CES-D <16 (65.1% vs 42.3%, p<0.01). No significant differences of plasma folate and serum Hcy levels were observed between the two groups. In logistic regression analyses, significant associations were observed between a CES-D score ≥16, low folate intake, and vitamin B6 intake, adjusted for age, living status, smoking, and body mass index. Compared with dietary folate intake of less that 240 µg/d, adequate folate intake of more than 240 µg/d, which is the recommended dietary allowance (RDA) level, was independently related to a decreased risk of depression (adjusted odds ratio: 0.41, 95% CI: 0.12-0.85, p<0.05).

Conclusion/Implications for nursing practice: Multiple logistic regression analyses revealed a reduced risk of the women experiencing depression when they exceeded the RDA-recommended folate intake level (240 µg/d). This finding suggests the possibility that promoting dietary folate intake may be effective in preventing not only neural tube defects, but also depressive symptoms in reproductive-aged women.

Keywords: dietary folate intake; depression; reproductive-aged women