Abstract
Background: In this study, we aimed to investigate the association of dietary phytochemical index (DPI) with insulin resistance, β-cell dysfunction, and insulin sensitivity. Methods: This longitudinal study was conducted on 1141 participants of the Tehran Lipid and Glucose Study. Dietary data were collected using a validated semi-quantitative FFQ with 168 food items at baseline and DPI was calculated. Fasting serum insulin and glucose were measured at baseline and again after a 3-year of follow-up. Results: After 3-years of follow-up, the risk of hyperinsulinemia significantly decreased by 65 (OR = 0.35, 95% CI = 0.21–0.60) and 86% (OR = 0.14, 0.07–0.29), in the third and fourth quartile categories of DPI, respectively. The occurrence of insulin resistance and insulin insensitivity in participants with higher DPI was significantly lower than the others (OR = 0.48, 95% CI = 0.25–0.93 and OR = 0.11, 95% CI = 0.05–0.24, respectively). Conclusion: Higher consumption of phytochemical-rich foods may have protective effects against development of insulin resistance.
Acknowledgments
The authors thank the Tehran Lipid and Glucose Study participants and the field investigators of the Tehran Lipid and Glucose Study for their cooperation and assistance in physical examinations, biochemical and nutritional evaluation and database management. The authors thank Ms N. Shiva for critical editing of the English grammar and syntax of the manuscript.
Declaration of interest
The authors report that they have no conflict of interest. This study was supported by grant no. 121 from the National Research Council of the Islamic Republic of Iran and the Research Institute for Endocrine Sciences of Shahid Beheshti University of Medical Sciences.