Association between depressive symptoms and multiple nutrient intakes in US adults: A cross-sectional study using NHANES 2017-2018

Emerging evidence suggests dietary nutrients influence mental health. This study examined associations between multiple nutrient intakes and depressive symptoms in a large sample of US adults. This cross-sectional study used data from the National Health and Nutrition Examination Survey (NHANES) 2017-2018. Adults aged ≥18 years with complete Patient Health Questionnaire-9 (PHQ-9) data were included (N = 5,068). Nutrient intake was assessed using two-day averaged 24-hour dietary recalls. Multiple linear and logistic regression analyses were conducted, adjusting for age, sex, body mass index, smoking status, and total energy intake. Bonferroni correction (α = 0.00625) was applied for multiple comparisons. Depression prevalence (PHQ-9 ≥ 10) was 9.1% (n = 459). In fully adjusted models, dietary fiber (β = -0.042), folate (β = -0.0018), magnesium (β = -0.0027), and selenium (β = -0.0054) were inversely associated with PHQ-9 scores (all p < 0.001). Per 1-SD increase, folate (OR = 0.72, 95% CI: 0.61-0.85), dietary fiber (OR = 0.77, 95% CI: 0.66-0.89), magnesium (OR = 0.80, 95% CI: 0.68-0.94), and selenium (OR = 0.81, 95% CI: 0.69-0.96) were associated with lower depression odds. Higher intakes of dietary fiber, folate, magnesium, and selenium were inversely associated with depressive symptoms in US adults. Survey-weighted sensitivity analyses confirmed that the associations for dietary fiber, folate, and magnesium were robust to NHANES complex sampling weights. Unweighted analyses were the primary analytic approach, and results should be interpreted as internal associations within the analytic sample. These cross-sectional findings warrant confirmation through longitudinal and interventional studies. • Dietary fiber, folate, magnesium, and selenium inversely associated with depression • Cross-sectional analysis of 5,068 NHANES 2017-2018 US adults using PHQ-9 • Folate showed strongest inverse association (OR = 0.72, 95% CI: 0.61-0.85) • Clear dose-response relationships observed across nutrient intake tertiles • Survey-weighted sensitivity analyses confirmed robustness for fiber and folate