I have ER+ breast cancer.  Should I avoid soy?  

This is a common question we hear from some of our breast cancer survivors.  They are concerned that since soy has weak estrogen-like properties and their cancers are fueled by estrogen, all soy needs to be eliminated from the diet to reduce the risk of a breast cancer recurrence.

Fortunately, breast cancer research in this area does not support this conclusion and does not recommend eliminating soy from the diet.  In fact, a study published in the Journal of the American Medical Association in 2009 determined soy food intake is associated with decreased risk of death and of cancer recurrence.  When females consume soy in their teenage years as their bodies are developing, it can actually help prevent the development of breast cancer later on in life.

For breast cancer survivors, it is recommended to consume no more than three servings of whole soyfoods per day.  Servings are equivalent to: ½ cup of green soybeans, tofu, TVP, or tempeh; ¼ cup of soynuts or soy flour; or 1 cup of soymilk.   It is strongly recommended to avoid soy supplements in the form of isoflavones, as it is unknown how the body responds to those high dose supplements.  

Choosing whether to incorporate soy into the diet can be a deeply personal issue.  Even after hearing it is safe to consume soy, some women are still more comfortable with completely eliminating it from their intake.  Only you will know what you are comfortable with and how you would like to approach your diet after receiving a breast cancer diagnosis.  However, remember to look at the big picture when you’re striving to make changes.  Making changes such as eating 8-10 servings of fruits and vegetables per day, eating 1 serving of cruciferous vegetables (broccoli, cauliflower, cabbage, Brussels sprouts) daily, limiting processed food intake, exercising 30 minutes at least 5-6 days per week, and incorporating stress relief techniques are heavily supported in research for reducing risk of breast cancer and are part of this ‘big picture’.  

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