Dietary Patterns Are Associated with Risk of Diabetes Type 2: A Population-Based Case-Control Study

Objective: We aimed to assess the relationship between major dietary patterns and risk of diabetes type 2 among Iranian adults. Methods: In this population-based case-control study in Mazandaran province, we enrolled 332 subjects (110 newly diagnosed cases and 222 controls) aged 43 - 77 years. Dietary intakes were collected using a validated semi-quantitative food frequency questionnaire (FFQ). Data on demographic, anthropometric, socioeconomic characteristics and other covariates were collected using structured lifestyle questionnaires. Factor analysis was used to identify major dietary patterns. Odds ratios (OR) were calculated for risk of type 2 diabetes across quartiles of dietary pattern scores. Results: Three major dietary patterns were identified, including: "healthy", "transitional" and "traditional". A significant direct association was found between the transitional dietary pattern and risk of diabetes type 2 after adjustment of potential confounders (OR = 2.17; 95% CI: 1.0, 4.50; Ptrend = 0.02). The traditional dietary pattern was significantly associated with the increased risk of diabetes type 2 after controlling for confounders (OR = 2.13; 95% CI: 1.03, 4.41; Ptrend = 0.01). There was no significant relationship between healthy dietary pattern and risk of diabetes type 2. Conclusions: In conclusion, transitional dietary pattern characterized by high consumption of salt, organ meats, dried fruits, poultry, tea, low- fat dairy and other vegetables. Traditional dietary pattern characterized by high intakes of garlic, dough, high- fat dairy, dried fruits, red meats, grains, as well as animal and hydrogenated fats were associated with an increased risk of type 2 diabetes. No significant associations were found between the healthy dietary pattern and risk of diabetes type 2.