A Hospital-Based Case-Control Study on Whole- and Refined-Grain Intake and Risk of Stroke

INTRODUCTION: The aim of the present study was to ascertain the correlation between the intake of whole and refined grains and the risk of stroke in the Iranian adult population. METHOD: This hospital-based case-control study was conducted at Alzahra University Hospital, Isfahan, Iran, in 2008. The cases (n=195) were stroke patients admitted to the neurology ward, and the controls (n=195) were patients admitted to other wards in this center, with no prior history of cerebrovascular accident or any neurological disorders. The usual dietary intakes of the study participants during the previous year were assessed using a validated semi-quantitative food frequency questionnaire. Whole and refined grains were defined according to the definition of the American Association of Cereal Chemists International; foods that contained at least 8 g per 30 g of their weight were considered as whole grains. RESULTS: The mean age of the case and control groups was 68.0 (+/- 13.5) and 61.5 (+/- 10.5) years, respectively; 40% of the cases and 53.3% of the controls were female. The total intake of whole grains (27.8 +/- 4.3 vs. 29.4 +/- 3.6 g/d, P=0.77) and refined grains (264 +/- 11 vs. 296 +/- 13 g/d, P=0.07) was not significantly different between the cases and controls. After adjusting for potential confounders, individuals in the second tertile of refined grain intake had a two-fold higher odds of stroke (OR: 2.02; 95% CI: 1.08-3.71), compared to those in the first tertile. Furthermore, no significant relationships were observed between the consumption of whole grains and the risk of stroke, before or after adjustment for confounding variables. No significant trend was found between the tertiles of refined or whole grain intake and the risk of stroke. CONCLUSION: The authors did not find a statistically significant association between the intake of whole and refined grains and the risk of stroke. Further prospective studies on the relationship between both whole and refined grains and stroke are warranted.