The Dietary Phytochemical Index Is Inversely Associated With the Odds of Premature Coronary Artery Disease ( <scp>PCAD</scp> ) in Iranian Adults: Iran Premature Coronary Artery Disease ( <scp>IPAD</scp> ) Study

There is no evidence to prove the relationship between Dietary Phytochemical Index (DPI) and the incidence of premature coronary artery disease (PCAD) among the Iranian population. Therefore, this research investigates the association between the DPI score and the odds of PCAD within a nationally representative Iranian population. This case-control study was performed on 3161 (<i>n</i> = 2006 case and <i>n</i> = 1155 control) Iranian population < 70 y in women and < 60 y in men. Subjects showing normal results on coronary angiography comprised the control group, and those with stenotic lesions exceeding 75% in at least one coronary artery or over 50% in the left main coronary artery were identified as the case group. Information on dietary intake was collected using a validated 110-item food frequency questionnaire. Using the McCarthy equation, the DPI was calculated. A binary logistic regression model was used to evaluate the association between DPI and PCAD. The mean age of the study population was 53.7 (SD = 7.6) years, and 45.1% of them were female. In the unadjusted model, individuals in the highest quartile of DPI exhibited a significantly reduced likelihood of developing PCAD compared to those in the lowest quartile (OR = 0.25, 95% CI: 0.20-0.31, <i>P</i> trend < 0.001). Adjustment for potential confounders further reinforced the relationship, indicating that participants in the top DPI quartile had 89% reduced odds of PCAD relative to those in the first quartile (95% CI: 0.08-0.17, <i>P</i> trend < 0.001). Our findings revealed a significant negative association between the DPI and the odds of PCAD. However, more research is necessary to determine this association.