Dietary total antioxidant capacity in relation to stroke among Iranian adults

Limited data are available linking dietary total antioxidant capacity (TAC) to the risk of stroke. This study was conducted to investigate the association between dietary TAC and odds of stroke among Iranian adults.
This case-control study was done on 195 hospitalized stroke cases and 195 hospital-based controls in Al-Zahra hospital, Isfahan, Iran. Dietary intake of participants was assessed using a validated detailed food frequency questionnaire. Dietary TAC was estimated using the ferric-reducing antioxidant power (FRAP) international databases. Stroke was confirmed by a trained neurologist using standard imaging methods. Demographic information were obtained by related questionnaire. Anthropometric data were measured by appropriate scale and meter. Physical activity was also assessed by specific questionnaire and reported as MET-min/day.
Mean dietary TAC was not significantly different comparing cases and controls (10.2±6.0 vs 10.4±4.8, P= 0.61). However, after adjustment for potential confounders including dietary intakes of fiber and omega-3 fatty acids, we found almost significant inverse association between dietary TAC and odds of stroke; such that each unit increase in dietary TAC was associated with 29% reduced odds of stroke (OR: 0.71; 95% CI: 0.50-1.01, P= 0.06). When we examined the association across tertiles of dietary TAC, we found that after controlling for potential confounders, those in the top tertile of dietary TAC were 51% less likely to have stroke than those in the bottom tertile (marginally significant) (OR=0.49; 0.49-1.00, p=0.12).
We found an almost significant inverse association between dietary TAC and odds of stroke. Further studies of prospective design are required to confirm these findings.