Rarely a day goes by where we donâ€™t get an email from a woman who has been diagnosed with breast cancer who is worried about whether she should be eating soy products.
But as is being a widely reported today, a new study has found that women with breast cancer who ate soy had a decreased risk of death and recurrence.
Attention was first directed at soy when researchers began looking for an explanation for why women living in Asia had lower breast cancer rates than women living in the U.S., and noticed the vast differences in soy consumption. This was when we began hearing that eating soy could reduce breast cancer risk, and when many women began staring to eat tofu, drinking soymilk, and using soy supplements.
But as scientists began toÂ conduct laboratory studies to look for reasons why soy might decrease breast cancer risk, they found that when genistein, which is a type of isoflavone, was added to breast cancer cells they grew faster. Soon after, it was suggested that women who were taking tamoxifen and other anti-estrogens should avoid soy because they acted like weak estrogens, and could potentially counteract the tamoxifen or increase a womanâ€™s risk of recurrence.
Almost over night, soy moved from the â€œgoodâ€ column to the â€œbad.â€ Now a new study has shown that all of that concern was probably misplaced.
This new study, which was published in the Journal of the American Medical Association was conducted in Shanghai, China. The participants were 5042 women who were taking part in the Shanghai Breast Cancer Survival Study.Â After following the women for four years, the researchers found that the higher a womanâ€™s soy protein or soy isoflavone intake, the lower her risk of having a breast cancer recurrence or dying from the disease. This was true regardless of whether women had ER-positive or ER-negative tumors, whether or not they were taking tamoxifen, and whether they were pre- or postmenopausal.Â Although not studied, it is likely to be true for women on aromatase inhibitors as well.
As the investigators and the authors of an editorial that accompanied the study point out, there are differences in the Asian and American diet, especially when it comes to soy. Asian women are more likely to eat whole soy foods, like cooked soybeans, edamame, tofu, miso, and soy milk, whereas women in the U.S. tend to eat more processed foods that contain soyâ€”but at much lower levels.
This is additional evidence that women in the U.S. with breast cancer can feel even better about adding whole soy foods to their diet. To be sure, we need more studies in women to confirm this finding. But a study of this size that has been so well done and that shows no negative effects clearly suggests that eating soy will not increase your risk of a recurrence and that, in fact, it might even reduce it!
This study tells us something else. We canâ€™t over simplify the science.Â Soy is not a phytoestrogen but rather a â€œphytoSERM,â€ more like tamoxifen than estrogen. And we cannot automatically extrapolate from studies on cells and rats to women.Â Â Womenâ€™s bodies are more complicated and the animal data does not always translate.
This is why the Love/Avon Army of Women is so important! It allows researchers to conduct studies on women so that we can learn more about what happens in womenâ€™s bodies and get the answers we need faster!
There have been lots of studies that have looked at the effect of soy in cells and laboratory animals. But this was only the second study ever done that studied the effect of soy in women with breast cancer!!! The second!Â Join the Army of Women and be part of changing the paradigm of science.Â Be part of finding the answers and stoppingÂ breast cancer once and for all.