What Peter says is true. Certainly the brain atrophy I believe is blood type specific because the number of individuals in the study (23% I think) was the same number as the individuals with B type blood (the post is on a lower thread). I also agree with Peter that Tyrosine Kinase inhibition is not related to brain atrophy. I believe it is soy's ability to act as a Trypsin Inhibitor, (because of its Raffinose and Stachyose content). Trypsin inhibits Amyloid-Beta-Protein Precursor (APP - a substance implicated in the development of Alzheimer’s Disease). Thus when trypsin is inhibited (by soy) APP is formed and thus Alzheimer's risk is increased.
Please read on because I then tell you the good news.
Although this is true if you heat, or ferment soy, its ability to inhibit trypsin disapears. Also, I believe A's have a greater trypsin secretion (I'll have to do the searches on that one though). This is evident due to A's greater ability to digest soy.
As your concern is of cancer and soy, read below and put your mind at ease!!
Barnes, S., et al. Rationale for the use of genistein-containing soy matrices in chemoprevention trials for breast and prostate cancer. J Cell Biochem. 22S:181-187, 1995.
· Troll, W., et al. Soybean diet lowers breast tumor incidence in irradiated rats. Carcinogenesis. 1:469-472, 1980.
Societies with high consumption of soybeans - especially in the form of fermented soybean foods -
have only 25% of the incidence of breast cancer as the populations of Western countries; further double blind studies have confirmed the protective effects of isoflavonoids and lignans as the chemicals responsible for these benefits.
· Zheng, W., et al. Urinary excretion of isoflavonoids and the risk of breast cancer. Cancer Epidemiol Biomark Prev. 8:35-40, 1999.
The incidence of breast cancer is much lower in Asian countries than in Europe and the United States. A possible explanation is that Asian women have a much higher intake of soybean foods than Caucasian women. Some studies have suggested an inhibitory effect of soybean isoflavonoids on the development of breast cancer.
This study measured urinary excretion of isoflavonoids in 60 women with breast cancer and matched controls from a large population-based study in Shanghai. Urinary excretion of total isoflavonoids was found to be significantly lower in breast cancer patients compared to control subjects. The median excretion of all major isoflavonoids was 50% - 65% lower in breast cancer patients. Subjects in the highest tertile of urinary excretion of total isoflavonoids and of the individual isoflavonoids daidzein and glycetein had a 50% lower risk for breast cancer compared to subjects in the lowest tertile.
The authors concluded that this study supports the hypothesis that a high intake of soybean foods may reduce the risk of breast cancer.