December 13, 2007 – Products derived from soy, such as tofu, natto and miso, are believed to help prevent cardiovascular disease in women. This is what the results of a large survey indicate1 conducted over ten years with a cohort of more than 40,000 Japanese women aged 40 to 60.
The researchers assessed the daily intake of soy protein in each of the subjects, then identified cases of myocardial infarction and stroke in the cohort. According to the results, women who consumed the most soy were 60% less likely to suffer from cardiovascular problems compared to those who consumed the least.
In postmenopausal women, the risk reduction was up to 75%. The results do not indicate such a decrease in the incidence of cardiovascular disease in men relative to their consumption of soy products.
The cardioprotective effect observed in Japanese women is thought to be attributable to the isoflavones in soy, mainly genistein, daidzein and glycitein. These substances, also known as phytoestrogens, would have an action similar to the female hormone, the activity of which decreases notably at the time of menopause.
This decrease in hormonal activity predisposes women to cardiovascular disorders at the time of menopause, which occurs around the age of 40 to 60 years. Phytoestrogen intake could counter this increased cardiovascular risk in women in this age group, the researchers believe.
In addition to isoflavones, soy also contains polyunsaturated fatty acids, including linoleic acid, vitamin E and omega-3s. These nutrients may help lower blood cholesterol levels, lower blood pressure, and improve insulin tolerance.
It should be noted, however, that the amounts of soy protein consumed in Japan far exceed that of the Western average. In the present study, subjects who had a so-called moderate consumption of soya consumed approximately 20 times more than an average Westerner. Japanese women with the lowest risk of heart disease consumed the equivalent of about 45g of natto or 100g of tofu daily, the study results show.
Pierre Lefrançois – PasseportSanté.net
According to Radio-Canada.
1. Kokubo Y, Iso H, et al.Association of dietary intake of soy, beans, and isoflavones with risk of cerebral and myocardial infarctions in Japanese populations: the Japan Public Health Center-based (JPHC) study cohort I. Circulation. 2007 Nov 27; 116 (22): 2553-62.
