Soy - a powerful component in breast cancer treatment plans
I feel bad for soy. I dare you to name a food that has more controversy and ill will surrounding it. Whenever I mention soy as a super food to patients, 95% of the time I am met with a cringe. Not because of a personal distaste for the food, but because of rumors of danger. “Soy gives you breast cancer”, “soy is bad for women’s health”, “soy makes your estrogen too high”. Believe me, I’ve heard it all! This holiday season; let’s give soy a chance.
Mainly due to its isoflavone content, soy has positive research in high cholesterol, osteoporosis, improving cardiovascular disease risk and kidney function in post-menopausal women
, hot flashes, and breast cancer. When soy is consumed in its most natural form (think organic tofu or soy milk, and NOT a soy hotdog), in relatively modest amounts (1-3 servings per day), it is incredibly safe. I’ve scoured the research in search of data on soy and breast cancer. Let’s go!
Soy in Breast Cancer Prevention
The majority of observational studies show that higher soy consumption reduces risk of developing breast cancer. Of 51 studies, 29 found protective effects from higher soy consumption. Twenty-two found no effect, and none of the studies showed an increased risk.
No studies have shown that soy increases the risk of developing breast cancer
Furthermore, there is no evidence that soy consumption increases breast tissue density in pre- or post-menopausal women.
Therefore, I believe that soy can be safely used in women with no history of breast cancer, and we can use soy in conjunction with other therapies to prevent breast cancer in women with increased risk.
Soy and Breast Cancer Prognosis
Once diagnosed with breast cancer, soy is not only safe, but it should be seen as therapeutic. As soy isoflavone consumption increases, the risk of death decreases. Women with the highest isoflavone consumption (more than 16.3 mg/day), have a 54% reduction in the risk of death.
The minimum therapeutic dose to reduce the risk of death in breast cancer patients is 16.3 mg of isoflavones, which is equivalent to half a cup of soy milk per day
Soy and Breast Cancer Recurrence
Four studies have looked at the effect of soy on breast cancer recurrence. Two studies found no effect on recurrence, while two studies found protective effects at dosages of 62 mg soy isoflavones (3 ounces of tempeh plus one cup organic soy milk) per day. One study found a 34% reduction in risk of recurrence, while the other found a 26% reduced risk. One study found lower risk of recurrence among women on tamoxifen who were consuming an average of 26 mg isoflavones per day, and another study found a similar benefit among post-menopausal women on anastrozole. Importantly, no studies found an increased risk of recurrence from consumption of soy.
No studies have shown an increased risk of breast cancer recurrence with soy consumption, and some studies have even shown up to a 34% reduction of recurrence
Take Home Messages
1. If you were avoiding soy because of unsubstantiated fear, please take the above research into consideration
2. If you have a first degree relative with breast cancer, consider seeking the help of a naturopathic doctor. An ND can create a comprehensive treatment plan designed to decrease your risk of developing breast cancer
3. If you have had breast cancer, you should have a recurrence reduction plan
4. If you currently have breast cancer, know that the main goal of naturopathic medicine is to keep you healthy so you can continue with your conventionally prescribed treatments
5. If you have any other looming “question marks” regarding health (specific food trends, diets, supplements etc), consider seeking the guidance of an ND instead of Mr. Google.
Happy holidays to all!