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:

• Dietary phytochemical index
• DPI
• diet quality
• stroke
• case-control
• epidemiologic study
• dietry intakes
• food frequency questionnaire

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

Financial support of this work was provided by a grant from the Isfahan University of Medical Sciences, the Islamic Republic of Iran (no. 187028 IUMS). Financial support for conception, design, data analysis, and manuscript drafting comes from the School of Nutritional Sciences and Dietetics, Tehran University of Medical Sciences, Tehran, Iran.

Notes on contributors

Somaye Rigi

Somaye Rigi is a M.Sc. Candidate at the Department of Community Nutrition, School of Nutritional Sciences and Dietetics, Tehran University of Medical Sciences, Tehran, Iran. Her research interest is investigating the association between diet and chronic diseases.

Seyed Mohammad Mousavi

Seyed Mohammad Mousavi is currently a Ph.D. Student at the Department of Community Nutrition, School of Nutritional Sciences and Dietetics, Tehran University of Medical Sciences, Tehran, Iran.

Forough Shakeri

Forough Shakeri is a Postgraduate Student at Tehran University of Medical Sciences, Tehran, Iran.

Ammar Hassanzadeh Keshteli

Ammar Hassanzadeh Keshteli is a Postdoctoral Fellow at the Department of Biological Sciences, University of Alberta, Edmonton, Canada

Sanaz Benisi-Kohansal

Sanaz Benisi-Kohansal is currently a Ph.D. Student at the Department of Community Nutrition, School of Nutritional Sciences and Dietetics, Tehran University of Medical Sciences, Tehran, Iran.

Mohammad Saadatnia

Mohammad Saadatnia is a Professor of Neurology at the Department of Neurology, Isfahan Neurosciences Research Center, Isfahan University of Medical Sciences, Isfahan, Iran.

Ahmad Esmaillzadeh

Ahmad Esmaillzadeh is a Professor (full) at the Department of Community Nutrition, School of Nutritional Sciences and Dietetics, Tehran University of Medical Sciences, Tehran, Iran. His research interest is to develop and validate dietary strategies that effectively protect against obesity-related chronic conditions; including metabolic syndrome, cardiovascular disease, gastrointestinal disease, psychological disorders, and different types of cancer.