Dietary patterns are associated with depressive symptoms among Chinese adults: a case-control study with propensity score matching.

Purpose: Previous studies have indicated that consumption of particular foods or nutrients is associated with depressive symptoms, but little is known about the role of overall dietary patterns in depressive symptoms. We design this case-control study to evaluate the associations between dietary patterns and high depression symptoms in Chinese adults.

Methods: A total of 1351 participants with high depressive symptoms were matched with 1351 controls using the 1:1 ratio propensity score matching method. Dietary intake was assessed using a valid self-administered food frequency questionnaire, and high depressive symptoms were assessed with the Zung Self-Rating Depression Scale, wherein cutoff point of 45 was used as a definition of high depressive symptoms.

Results: Exploratory factor analysis revealed three dietary patterns (vegetables and fruits pattern; sweets pattern; and animal foods pattern) explaining 25.1 % of the total variance. Compared with the participants in the lowest quartile, the participants in the highest quartile of vegetables and fruits pattern, which was defined as a healthy pattern, were associated with reduced odds of high depressive symptoms (OR 0.65, 95 % CI 0.52-0.83, P for trend <0.001) while the sweets pattern (OR 1.33, 95 % CI 1.06-1.66) and the animal foods pattern (OR 1.79, 95 % CI 1.43-2.24, P for trend <0.0001) were associated with increased prevalence of high depressive symptoms, respectively.

Conclusion: The present study adds to the evidence that the sweets pattern and animal foods pattern are positively associated with the prevalence of high depressive symptoms. In contrast, the dietary pattern rich in vegetables, fruits, and soya bean products, but low in animal foods, candied fruits, cakes, ice cream, sugared beverages, and alcoholic drinks is negatively associated with the prevalence of high depressive symptoms.