But now (finally) we have clarification on the soy or no soy for women with breast cancer:
The issue is eating soy products seems to give women protection from breast cancer. Asian countries where soy products are eaten regularly have much lower rates of breast cancer than the US. But the estrogen-similar stuff in soy products has been thought to contribute to breast cancer growth, especially with hormone sensitive breast cancer.
So the truth was found in some recent research using rats:
"The researchers found that rats that were given soybean isoflavones to eat throughout their lives — in particular, one type of soybean isoflavone called genistein — had improved immunity against cancer. But rats that weren't given the isoflavone until after developing breast cancer didn't have that same immune response to kill cancer cells. Instead, these rats had higher rates of cancer growth and higher rates of recurrence after their tumors were removed."
"All of the rats were then treated with tamoxifen to kill the cancer. The researchers found that the rats raised on genistein had only a 7 percent chance of breast cancer recurrence after tamoxifen treatment, but the rats that were recently given genistein had a 33 percent recurrence rate."
So if you eat soy all your life, your risk of cancer should be lower and remain lower for recurrence. But if you are diagnosed with breast cancer, don't start eating soy.
See now I really have a good reason for not eating tofu.