A prospective study by a study team of the Japanese Health, Welfare and Labour Ministry investigated the association of lifestyle including dietary habits with the occurrence of cerebral infarction and myocardial infarction during the follow-up survey of about 11 years until 2002 on about 40,000 men and women who were 40-59 years of age and healthy at the start of the study in 1990.
According to the study, the women group with the highest isoflavone intake showed 0.35 times lower cerebral infarction risk and 0.37 times lower myocardial infarction risk, in total of the two 0.39, against the women group with the lowest isoflavone intake.　For postmenopausal women it was observed that the greater the intake the lower the risk of both diseases.
As to the mortality risk of cardiovascular diseases, the total of the top two groups of high isoflavone intake was found to be 0.17 times lower against that of the lowest intake group.　In the case of men, a similar association was not observed.