Seaweed consumption and prevalence of depressive symptoms during pregnancy in Japan: Baseline data from the Kyushu Okinawa Maternal and Child Health Study

BACKGROUND: Seaweed is a popular traditional food in Japan and is a rich source of bioactive metabolites. The neuroprotective properties of seaweed have attracted attention; to date, however, there has been no epidemiological evidence regarding the relationship between seaweed consumption and depression. The current cross-sectional study investigated the association between seaweed consumption and depressive symptoms during pregnancy in Japan. METHODS: Study subjects were 1745 pregnant women. Depressive symptoms were defined as present when subjects had a Center for Epidemiologic Studies Depression Scale score of 16 or higher. Dietary consumption during the preceding month was assessed using a self-administered diet history questionnaire. Adjustment was made for age; gestation; region of residence; number of children; family structure; history of depression; family history of depression; smoking; secondhand smoke exposure at home and at work; job type; household income; education; body mass index; and intake of fish and yogurt. RESULTS: The prevalence of depressive symptoms during pregnancy was 19.3%. After adjustment for possible dietary and non-dietary confounding factors, higher seaweed consumption was independently associated with a lower prevalence of depressive symptoms during pregnancy: the adjusted odds ratios (95% confidence intervals) for depressive symptoms during pregnancy in the first, second, third, and fourth quartiles of seaweed consumption were 1 (reference), 0.72 (0.51 - 1.004), 0.71 (0.50 - 1.01), and 0.68 (0.47 - 0.96), respectively (P for trend = 0.03). CONCLUSIONS: The present results suggest that seaweed consumption may be inversely associated with the prevalence of depressive symptoms during pregnancy in Japanese women.