Dietary folate and depressive symptoms are associated in middle-aged Finnish men

Several cross-sectional studies have focused on the low blood folate levels of depressed patients. However, no published studies have examined the association between dietary folate and current symptoms of depression in a general population. We investigated the association between dietary folate, cobalamin, pyridoxine and riboflavin and current symptoms of depression in a cross-sectional general population study. We recruited 2682 men aged between 42 and 60 y from eastern Finland. Those who had a previous history of psychiatric disorder were excluded (n = 146, 5.6% of the cohort). Depressive symptoms were assessed with the 18-item Human Population Laboratory Depression Scale. Those who scored 5 or more at baseline were considered to have elevated depressive symptoms (n = 228, 9.3% of the cohort). The participants were grouped into thirds according to their dietary folate intake. Those in the lowest third of energy-adjusted folate intake had a higher risk of being depressed [odds ratio (OR) 1.67, 95% CI = 1.19-2.35, P = 0.003] than those in the highest folate intake third. This increased risk remained significant after adjustment for smoking habits, alcohol consumption, appetite, BMI, marital status, education, adulthood socioeconomic status and total fat consumption (OR = 1.46, 95% CI = 1.01-2.12, P = 0.044). There were no associations between the intake of cobalamin, pyridoxine or riboflavin, and depression. These results indicate that nutrition may have a role in the prevention of depression.