Dietary patterns and dietary phytochemical index are associated with major depression disorder in females: A case–control study

Background and aims

Previous research has linked dietary patterns to depressive disorders, however, there are limited data on the association between the consumption of diets rich in phytochemicals and these disorders. This study aimed to investigate the association between dietary patterns and dietary phytochemical index (DPI) and major depression disorder (MDD) in Iranian females.

Methods

This case–control study was performed on 261 Iranian women (18–65 years, 87 cases, and 174 controls). Food intakes were assessed using a validated semi-quantitative food frequency questionnaire (FFQ). Depression was evaluated by a psychiatrist according to DSM IV criteria. We used factor analysis to extract dietary patterns and binary logistic regression to assess the relationship between dietary pattern scores and depression.

Results

Two major dietary patterns were identified: healthy and unhealthy patterns. After controlling for these variables, participants in the highest tertile of the healthy dietary pattern had significantly lower OR for major depression (OR = 0.371; 95% CI: 0.168–0.819, p =.014). The second tertile of the unhealthy dietary pattern, compared with the lowest tertile had a higher OR for major depression (OR = 3.162; 95% CI: 1.451–6.889, p = 0.004). Also, women in the lowest tertile of DPI had a higher risk of major depression (OR 2.668; 95% CI 1.297, 5.491, p =.008) compared with those in the highest tertile.

Conclusions

We found that adherence to a healthy dietary pattern and high intakes of phytochemicals is associated with reduced risk, while an unhealthy dietary pattern is associated with an elevated risk of major depression.