Soy and Breast Cancer – Exploring the Research

If you’re a breast cancer survivor, you may be feeling some confusion around soy and breast cancer. This is a topic that I am often asked about and leads to much discussion.

Exploring the current research and latest nutrition studies can help you decide to include and ultimately enjoy this healthy plant protein in your diet.

Soy and Breast Cancer Study

The latest study on soy and breast cancer (study abstract) included 6,235 American and Canadian breast cancer patients from the Breast Cancer Family Registry. By looking at this diverse population of over 6,000 breast cancer patients, the researchers specifically analyzed their soy intake. And the results were pretty amazing.

Here’s a summary of the top takeaways:

Higher Survival Rates

Eating foods rich in isoflavones (the specific phytoestrogens in soy foods) is associated with reduced all-cause mortality. More specifically, researchers found a 21% decreased risk of death among women with the highest versus the lowest intake of soy foods. This was especially true in women with hormone-receptor-negative breast cancer (which is typically the more aggressive kind) and women not treated with hormone therapy.

Women in North America could benefit from increased organic soy consumption

Even though women living in North America had an overall low consumption of soy in their diet, they may still benefit from increasing their isoflavone intake to a higher level. This benefit may be for those thrivers who are not currently receiving hormone therapy, but there’s also no negative impact shown for those who are.

Increasing soy may increase survival rate after a cancer diagnosis:

If you’ve been diagnosed with ER-negative breast cancer, soy may play a significant role in your survival, and may even matter more if you start eating it now than if you ate it way back when. So not only did this study find that soy wasn’t harmful for survival, but it actually may improve it. And while this study only found these specific perks for ER-negative survivors, previous research has found soy to be beneficial for ER-positive survivors and for both users and nonusers of hormone therapy. Happy dance!

Breast Cancer Prevention and Soy

Studies also show that eating soy can help prevent breast cancer in women of all ages. Researchers found that soy consumption cuts breast cancer risk by 41 percent. But here’s the catch––it can’t be just any type of soy.

To eat soy for its preventative benefits, it has to be the less processed versions, such as tempeh, miso, edamame, and non-GMO tofu.

Prevention is also linked to how long you’ve been eating soy. Asian women have the lowest incidence of breast cancer, most likely from eating soy during puberty when breast tissue was forming. However, it could be worthwhile to add some unprocessed soy foods to your diet, even if you’re past puberty.

Including organic soy in one’s diet provides more variety and protein options. There are also just so many great dishes and recipes you can make that include healthy soy options!

Try this delicious Tempeh Stir Fry recipe, packed with proteins, dietary fibre and vitamins!


“What you need to know about soy and breast cancer” Kris Carr, Retrieved 26 July2017. <>

“Dietary isoflavone intake and all-cause mortality in breast cancer survivors: The Breast Cancer Family Registry” American Cancer Society, Pub Med, Published 01 June 2017. <>