Should I include soy products in my cancer-smart diet?

As a clinician, I continue to get asked many questions about the prostate benefits of soy products. Are soy foods good for prostate cancer?" The curiosity stemmed from numerous articles she read on the internet associating prostate cancer benefits from soy consumption.


Can soy, a popular meat substitute, protect against prostate cancer? 


Soybeans contain fiber, polyunsaturated fats, potassium, magnesium, and other vital vitamins. It also has all the required amino acids—the building blocks of protein—which is why soy is popular among vegetarians and vegans as a source of protein. 


Soy products are broken down into two categories:

  1. Unfermented soy: tofu, soymilk, edamame, soy nuts, and sprouts; and
  2. Fermented soy: miso, tempeh, natto, and soy sauce.


One major research study shows that two ingredients in soy, genistein, and daidzein, are associated with a lower risk of prostate cancer. Further, unfermented soy food products were associated with a decreased risk of prostate cancer, while fermented soy food products had no associations with prostate cancer risk.  


The rates of prostate malignancy are lower in Asian countries (where soy is a diet staple) compared with Western countries. This could be due to equol, a by-product of soy gut bacteria produce. Some research has found that equol is associated with a lower prostate cancer risk. However, not everyone can break down soy to make equol. One study found that American men produce less equal than Japanese and Korean men. So, can non-Asian men make enough equol from soy to protect themselves against prostate cancer? Likely not.


Even though isoflavones in soy are a type of phytoestrogen, which may have a similar effect on the body as estrogen, one research article has shown that soy does not increase estrogen levels in men. 


There is much confusion about soy and prostate cancer. Whether it may protect against prostate cancer or help manage your diagnosis is unclear. Until then, I think it's perfect for men to enjoy soy in moderation. Also, it's not a good idea to think of any one food as a panacea. At XY Wellness, we believe the whole integrative roadmap is better than the sum of its parts. Eating a variety of optimal, clean foods that include broccoli, brussels sprouts, cauliflower, and cruciferous vegetables is best – they are called and have been shown to have prostate cancer protection. 


Final Thoughts and Takeaway from Eating Soy


Later in our dinner last night, I passed on the soy ice cream. I'd avoid fake soy products like soy ice cream, soy burgers or soy hot dogs. Fake foods are crap too. If you want ice cream, have ice cream. Feel free to consume one to two daily servings of soy in the form of tofu or tempeh. A couple of cups of soymilk a week may also be beneficial and contain benefits in fighting prostate cancer. Again, one food is never a cure for any disease. Cancer is a complex and multifaceted group of diseases, and no magic bullet can eliminate it entirely. However, a balanced, whole foods diet can significantly reduce the risk of developing and progressing prostate cancer.


Much Love!


Dr. Geo, Co-founder & Medical Director