Objective: Recent evidence suggests a role for diet quality in the common mental disorders depression and anxiety. We aimed to investigate the association between diet quality, dietary patterns, and the common mental disorders in Norwegian adults.
Methods: This cross-sectional study included 5731 population-based men and women aged 46 to 49 and 70 to 74 years. Habitual diet was assessed using a validated food frequency questionnaire, and mental health was measured using the Hospital Anxiety and Depression Scale.
Results: After adjustments for variables including age, education, income, physical activity, smoking, and alcohol consumption, an a priori healthy diet quality score was inversely related to depression (odds ratio [OR] = 0.71, 95% confidence interval [CI] = 0.59-0.84) and anxiety (OR = 0.77, 95% CI = 0.68-0.87) in women and to depression (OR = 0.83, 95% CI = 0.70-0.99) in men. Women scoring higher on a healthy dietary pattern were less likely to be depressed (OR = 0.68, 95% CI = 0.57-0.82) or anxious (OR = 0.87, 95% CI = 0.77-0.98), whereas men were more likely to be anxious (OR = 1.19, 95% CI = 1.03-1.38). A traditional Norwegian dietary pattern was also associated with reduced depression in women (OR = 0.77, 95% CI = 0.64-0.92) and anxiety in men (OR = 0.77, 95% CI = 0.61-0.96). A western-type diet was associated with increased anxiety in men (OR = 1.27, 95% CI = 1.14-1.42) and women (OR = 1.29, 95% CI = 1.17-1.43) before final adjustment for energy intake.
Conclusions: In this study, those with better quality diets were less likely to be depressed, whereas a higher intake of processed and unhealthy foods was associated with increased anxiety.