Dr. D'Adamo,

I am aware that you may not answer this question, but I will attempt because I am very confused. I understand the concept of eating for your blood type. But, as a cancer survivor and a Type A - I'm having trouble connecting the soy issue. I read an answer you wrote on your web site, but it was so medically scientific I couldn't understand.

Do you believe that soy is linked to cancer? If so, do you believe it is linked to Type A's? How do you justify putting someone on a high soy diet and not be concerned about cancer?

Thank you for your time.

M.

Soy is not linked to cancer. Some cancers are estrogen sensitive and the theory is that since soy contains a form of plant estrogen, these plant estrogens might work to stimulate cancer, just as the biological forms of estrogen do.

However, soy estrogens are very weak estrogens (tamoxifen, by the way, is also a weak estrogen) so in most situations they block the estrogen receptor, more than stimulate it. Soy also has two other functions which make it desirable in cancer patients, particularly those who are type A. It contains a protein, soy bean agglutinin, which can target cancer cells directly and help to kill them.

The flavones in soy, in particular genistein help keep genes methylated, which tends to suppress any cancer tendencies. Finally soy is rich in saponin molecules which has independent ant-cancer mechanisms of their own. A 2008 Japanese study was published on soy consumption and rates of breast cancer. This study looked at 24,226 Japanese women aged 40 to 69. Women who had the most consistently high levels of genistein had the lowest rates of breast cancer.Historically, breast cancer rates in the United States have been 4-7 times those in Asia, whereas isoflavone intake in the United States is less than 1% that in Asian populations.

You will hear and read a lot of garbage about soy on the internet. If you were to take the advice of some of these sites and authorities, you might as well give up most nuts, fruits and vegetables since they contribute more phytoestrogens into the average American diet than do soy products. Yet Americans have higher breast cancer rates than cultures where soy is a bigger part of the diet. Finally, many of the anti-soy crusaders point to a potential for soy to block mineral absorption, as it contains chemicals phytates. This might be true if soy were consumed in astronomical doses, but better evidence suggests that phytate containing foods also appear to block the development of colon cancer as well.

Bear in mind it is not a perfect food in everyone. However if you look at the dynamics of the type A immune system, it would appear to be a very useful food in these people.