Joy in Soy

Breast cancer survivors benefit from dietary soy products

/ Author:  / Reviewed by: Joseph V. Madia, MD

(RxWiki News) Is it okay for women who have breast cancer and other hormone sensitive cancers to eat soy and other plant based phytoestrogens? That’s a controversy that’s been raging for several years.

Researchers now say that dietary soy is safe for women with hormone sensitive cancers. However, phytoestrogen supplements remain risky.

Soy contains phytoestrogens, which are a group of natural compounds that are similar to estrogen. Estrogen is one of the hormones that controls important functions in the human body including reproduction, metabolism, and maintenance of bone density. Estrogen also drives tumor growth in certain cancers such as breast cancer.

"If you have breast cancer, it’s okay to consume dietary soy."

Because they behave like estrogen, there has been a long-running debate regarding whether or not phytoestrogens are good for hormone sensitive cancers, including breast cancer. The answer, at this point, lies in the type and form of phytoestrogen being consumed.

There have been many conflicting studies conducted to determine if supplemental phytoestrogens can benefit breast cancer patients. Some studies say that phytoestrogens can drive tumor growth and others say that they block estrogen to stop tumor growth.

The mechanisms of how phytoestrogens work is still unknown, which fuels the controversy.

Writing in the current issue of Inside Integrative Medicine, Judith Smith and Lorenzo Cohen from The University of Texas MD Anderson Cancer Center say, "Even though phytoestrogens are individually evaluated, very rarely is there only one type of phytoestrogen commercially available, hence safety can be mixed."

Bottom line - phytoestrogen herbal supplements remain risky, so "women with a history of hormone-mediated cancer should use caution with using these compounds," according to Smith and Cohen.

However, some foods that contain phytoestrogens - like soy products - are safe to consume. Smith and Cohen state, " Recent observational studies of women with breast cancer suggest that dietary soy as part of a normal diet is probably safe and, in fact, may be beneficial for women with breast cancer." So, consuming soy is harmless and may even provide benefits for women with breast cancer.

Here’s a list of safe soy products to include in your diet:

  • Tofu
  • Edamame
  • Soy Nuts
  • Soy Milk
  • Soy Bean
Reviewed by: 
Review Date: 
May 31, 2011
Last Updated:
July 5, 2013