Dietary niacin intake in relation to depression among adults: a population-based study

BACKGROUND: Previous studies have shown that an antioxidant diet is a protective factor against depression. However, the association between niacin, an important antioxidant consumed from the diet, and depression has received little attention. Therefore, we explored the association between niacin intake and depression through a cross-sectional analysis of the National Health and Nutrition Examination Survey (NHANES) from 2007 to 2016. METHODS: Depression was measured using the Patient Health Questionnaire (PHQ-9, score ≥ 10). Niacin intake was assessed through 24-h dietary recall interviews. The relationship of niacin intake with depression among adults in US was assessed by using a weighted multiple logistic regression model with subgroup analysis. Non-linear associations were explored using restricted cubic spline models. And we used a two-piece-wise logistic regression model with smoothing to explore the threshold for association between them. RESULTS: A total of 16,098 adults were included in this study. Compared with individuals with lowest niacin intake Q1 (≤ 15.96 mg/day), the adjusted OR values for dietary niacin intake and depression in Q2 (15.97-22.86 mg/day), Q3 (22.87-32.28 mg/day) and Q4 (≥ 32.29 mg/day), were 0.92 (95% CI: 0.70-1.20), 0.76 (95% CI: 0.56-0.99,) and 0.68 (95% CI: 0.48-0.98), respectively. The results were not modified by sex, by age and by BMI. Furthermore, the relationship between dietary niacin intake and depression exhibited a U-shaped curve (nonlinear, p < 0.001). And depression risk was lowest when dietary consumption of niacin was around 36 mg/day. CONCLUSIONS: In present study, moderate niacin intake, but not high intake, was associated with lower odds of depression suggesting a U-shaped association.