The association between dairy products and psychological disorders in a large sample of Iranian adults

Dairy products contain certain nutrients that are useful in mental disorders. This study aimed to assess the associations between dairy products and psychological disorders in a large sample of Iran, a Middle Eastern country.

This cross-sectional study was undertaken on 7387 adults. Data on dietary intakes were obtained using a validated Food Frequency Questionnaire. Psychological health was assessed by the Iranian validated version of depression, anxiety, and stress scale 21. Multivariable logistic regression analysis was performed to analyze the association between dairy intake and psychological disorders.

After adjustment for potential confounders, total milk consumption (OR for the highest vs. lowest tertile: 0.73, 0.58-0.92) and total yogurt consumption (0.78, 0.62-0.97) were associated with decreased odds of depression. An inverse relationship was found between total dairy (0.73, 95% CI 0.590.91), total milk (0.72; 0.58-0.88), kashk (0.79, 0.65-0.96), and yogurt drink (0.80, 95% CI 0.65-0.98) consumption and anxiety symptoms. Higher intake of cheese was related to greater odds of stress (1.52, 1.02-2.26). No association was found between the consumption of high-fat dairy, low-fat dairy, low-fat milk, low-fat yogurt, high-fat yogurt, cheese, kashk, yogurt drink, and depression. Also, there is no association between dairy products and stress symptoms. This association was significant among men and women and high-fat and low-fat products in the total adjusted stratified analysis models.

Findings of this study revealed that both high-fat and low-fat dairy products are associated with a reduced prevalence of psychological disorders. Still, more prospective studies are required to confirm these associations.