Soy protects against ischemic strokeIschemic stroke is a major cause of mortality and morbidity. In an ischemic stroke, blood supply to part of the brain is decreased, resulting in dysfunction of the brain tissue in that area.
Liang W and coworkers Curtin University of Technology, Perth, Australia, were the first to confirm this association in an epidemiological study. They investigated the link between soy food consumption and the risk of ischemic stroke among a Chinese population in a case-control study. They compared soyfood consumption and lifestyle factors from 347 stroke patients, who suffered from ischemic stroke, with those of 464 control subjects. Dietary assessment was done by a validated and reliable questionnaire. Total soy intake was defined as the sum of soybeans, tofu and soymilk.
The researchers found that the mean weekly soy food intake was significantly lower among stroke patients (90 g) than control subjects (268 g). Subjects who consumed minimum 300 g soy products had 77% less risk to develop stroke than those who consumed less than 50 gram soy products. Also, each specific soyfood intake showed a dose-dependent relationship with stroke incidents. Other factors that affected stroke risk were smoking, physical activity and consumption of fruit and vegetables.
The researchers recommend more similar studies in other populations and confirmation with well-designed prospective cohort studies.
Source: Soy consumption reduces risk of ischemic stroke: a case-control study in southern china. Neuroepidemiology 2009;33(2):111-6.