Dietary phytochemical index in relation to risk of stroke: a case-control study

Abstract

Background & aim: No study explores the association of dietary phytochemical index (DPI) with stroke. This study was undertaken to obtain the required insight in this regard in Iranian adults.

Methods: This hospital-based case-control study was carried out on 195 stroke patients (diagnosed based on clinical and brained CT findings) and 195 control subjects with no history of cerebrovascular diseases or neurologic disorders). Data collection on dietary intakes was done using a 168-item validated FFQ. DPI was calculated using the McCarty equation. Logistic regression model in different models was used to evaluate the association between DPI and stroke.

Results: Mean age of study participants was 64.8 years, and 53.4% of them were male. Individuals in the highest tertile of DPI were younger (63 ± 11 vs. 67.4 ± 13 y, P = 0.01) and less likely to be physically active (2804 ± 5714 vs. 4772 ± 11912 M, P = 0.03). After adjustment for potential confounders, no significant relationship was observed between DPI and stroke risk (OR: 0.76; 95% CI: 0.39-1.49). However, when we considered the effect of dietary intakes, subjects in the top tertile of DPI were 61% less likely to have a stroke than those in the bottom tertile (OR: 0.39; 95% CI: 0.16-0.95). When BMI was controlled, the association between DPI and stroke became strengthened (OR: 0.32; 95% CI: 0.12-0.86).

Conclusion: We found evidence indicating a significant inverse association between DPI and odds of stroke in adults. Further prospective studies are warranted to confirm this association.

Keywords: DPI; Dietary phytochemical index; case-control; diet quality; dietry intakes; epidemiologic study; food frequency questionnaire; stroke.