Over the past few years I have heard an increasing amount of questions in regards to the benefits of soy protein as well as the potential link to cancer, especially breast cancer. Researchers started exploring the impact soy has on one’s health as it had become clear the incidence of overall cancer and breast cancer was lower among those living in Asia compared to those in North America. This sparked numerous studies to be launched to explore soy foods because Asian diets are saturated in soy-based foods (e.g., tofu and edamame).
Soy and Cancer Risk:
Phytoestrogen, a soy isoflavone, had been thought to potentially bind to estrogen-- which would then decrease the development of cancer. This thought is due to excessive or high levels of estrogen has been linked to cancer promotion. Some earlier studies (with rats/mice as the subject) using soy showed soy had been linked to breast cancer promotion due to an increasing growth of an estrogen receptor. However, as of 2011 the American Institute of Cancer Research determined that mice or rats (used for a lot of earlier soy research) metabolize the isoflavones differently than humans. This is a huge factor when it really boils down—not only do we metabolize soy differently, but the amount of soy in our diet comes into question.
In general, Americans consume, at most, 1-2 mg/day (half of one serving) of soy protein according to the American Cancer Society. This amount is much less compared to the Asian diet as they consume up to 2-3 servings of soy protein per day. The largest study to date looked over 10,000 breast cancer survivors and actually showed improved outcomes—those consuming 10 mg/day of isoflavones had 25% decrease in recurrence of breast cancer. This helps clear the air. The next question would then be “what foods can I eat to get more soy into my day??”
Soy and Other Health Benefits:
Adding soy protein in its least processed form is most ideal. This does not mean loading up the cart with soy protein nuggets and burgers from the freezer isle. This means incorporating edamame, tofu, tempeh, soynuts and soy beverages. The minimally processed soy protein sources have been linked to heart health and is packed with protein, fiber, potassium, magnesium, calcium (in some sources), copper, manganese, and phytochemicals such as phytic acid, phenolic acid and more. Here are some ideas for your weekly meal plan:
- Meatless Monday: Tofu lasagna for dinner
- Tuesday: ¼ cup edamame for one metabomeal
- Wednesday: Silken tofu, ground flaxseed, frozen berry, and ice smoothie for breakfast
- Thursday: Tempeh chili incorporated at dinner
- Friday: 2 T. roasted soynuts on your lunchtime salad
- Saturday: Sushi night with edamame as your first course
- Sunday: Buckwheat tofu and banana pancakes (made with silken tofu)