Supplementary Material for: Soy Consumption Reduces Risk of Ischemic Stroke: A Case-Control Study in Southern China

Background: Experimental studies have suggested that soybean products may protect against ischemic stroke, but only limited epidemiological evidence is available. Objective: Our aim was to investigate the relationship between soy food consumption and the risk of ischemic stroke among the Chinese population. Methods: A case-control study was conducted in southern China during 2007–2008. Soy food consumption, dietary intake and lifestyle information were obtained from 374 incident ischemic stroke patients and 464 hospital-based controls. Logistic regression analyses were performed to assess the association between soy food intake and the ischemic stroke risk. Results: The mean weekly soy food intake was significantly lower (p = 0.001) among cases (89.9, SD = 239.3 g) than control subjects (267.7, SD = 426.1 g). Increased consumptions of dried soybean, tofu, soymilk and total soy foods were associated with reduced risks of ischemic stroke after adjusting for confounding factors. The corresponding adjusted odds ratios for the highest versus lowest level (<50 g) of intake were 0.20 (95% confidence interval = 0.09–0.48), 0.56 (0.36–0.89), 0.18 (0.06–0.51) and 0.23 (0.14–0.39), with significant dose-response relationships observed. Conclusion: The results provided evidence of inverse association between habitual soy food consumption and the risk of ischemic stroke for Chinese adults.