Doctor's Note

More on soy’s role in preventing breast cancer:

BRCA Breast Cancer Genes and Soy
Breast Cancer Survival and Soy
GMO Soy and Breast Cancer

And check out my video on Soy and Breast Cancer Survival, and the accompanying blog post

Also see my associated blog posts for more context: Eating To Extend Our LifespanStool Size and Breast Cancer RiskBreast Cancer and Diet; and Soy and breast cancer: an update.

If you haven’t yet, you can subscribe to my videos for free by clicking here.

To post comments or questions into our discussion board, first log into Disqus with your account or with one of the accepted social media logins. Click on Login to choose a login method. Click here for help.

  • Michael Greger M.D.

    Please feel free to post any ask-the-doctor type questions here in the comments section and I’d be happy to try to answer them. And check out the Soy and Breast Cancer Survival video and the accompanying blogpost. Also, there are 1,449 other subjects covered in the rest of my videos–please feel free to explore them as well!

  • HereHere

    I appreciate the fact that you have raised how researchers are still using animals for studies that have no applicability to human health. It boggles my mind, as I thought the research community was required to look at alternatives to using animals for research, assessing whether there is a human benefit or need for the research on animals, having to pass by an ethics review panel and having to exam opportunities to minimize the number of animals used for the study. I am shocked that this irrelevant research continues as it does.

  • There’s so much contradictory information out there, I would like to know your take on this quote that I found in an email I received from “These days, people turn to soy milk. Even if you’re not turned off by the fact that it’s an industrial waste product spun by marketers into a so-called “health food,” you can’t like the numerous health-risks associated with soy. (I’ll be writing more on those later in the week. But as a foretaste of things to come, soy: is thyroid suppressing, blocks absorption of minerals like calcium, causes hormonal imbalance leading to infertility and breast cancer, disrupts protein digestion, can cause growth problems in children).”

  • DrDons

    When reading claims on other websites I would tend to discount the claims unless they cite references with links to abstracts(and articles when free) like Even then the studies can be misleading see Alot of misinformation about soy exists including fertility in males see; the issue re: thyroid and soy … Dr. Greger addressed in a 8/24/11 response… “Soy does indeed have so-called “goitrogenic” compounds (as does broccoli-family vegetables and flax seeds), which can interfere with thyroid function in people with marginal iodine intake. The answer is not to avoid these super healthy foods but to just make sure you get enough iodine”. See his video on Avoiding Iodine Deficiency.. Soy seems to have benefits compared to standard american diet as far as hormones are concerned see and As far as calcium absorption of soy vs cow’s milk see Calf’s milk has calcium but comes with negative factors see Soy appears to be fine based on the science but stay tuned as the science is changing all the time.

  • Michael Greger M.D.

    Also be sure to check out my associated blog post Breast Cancer and Diet!

  • Lois

    I would have to disagree with this report because in the US we use a cheap soy – not the fermented soy used in Asian countries.  When my cousin had breast cancer her oncologist actually ranted some about soy products as she was the third or fourth young women he had seen that day with estrogen related breast cancer.  She ate soy products, health food bars, and soy milk thinking they were healthy.  I won’t touch soy products except on occasion or if natural.  I use coconut milk as I’m allergic to milk.

  • Mark

    Hi Dr. Greger,

    So soy has been shown to have benefits for women, but what about men?
    Surely those phyto-estrogens could create problems, like gynecomastia?

    Thanks Dr.,


  • guesttest

    what about soy and estrogen hormone in men exercising actively in the gym targeting muscle building and fat loss? thanks…

  • Mikotan

    Hi, I have been researching about soy milk, whether it is harmful or beneficial. And i came across lots of information about harmful effects. Dr Marcola is one of them. I am so confused. They say, traditionally fermented soy products are okey but non-fermented soy products are toxic. I am Japanese who lived there for 37 years enjoyed eating non-fermented soy products regularly (plain tofu, baked tofu, fried tofu、dried tofu…we have a variety of tofu products and each product is used for different type of dishes traditionally….and ). The western people think tofu is that white square stuff but we have more varieties and it is not unusual eating them almost everyday? We have been eating tofu for hundreds of years???(perhaps from the 7th centuries?) I just don’t get it. I use non-GM soya milk for my smoothies everyday so I am consuming probably 300ml everyday in average…and I am not eating these different types of tofu products now? Am I going to become sick because of taking non-fermented food everyday??????