Another common concern is the issue of breast cancer. What you may find surprising is that soy consumption in Asia is actually linked to a lower risk of breast cancer. In fact, those who consume just ½ a cup of tofu per day reduce their risk of developing breast cancer by an astonishing 30% compared to those who avoid soy![9] Even women who previously battled breast cancer have 21% greater survival rates over the course of 9 years if they consume more soy.[10] And finally, those with BRCA gene mutations, which put them at higher risk of breast cancer, also may benefit from increased soy consumption.[11] This is likely due to the anti-estrogenic effects of soy in breast tissue that I discussed earlier.[5][6]
But what about other cancers? A study including over 46,000 women found a 30% reduction in endometrial cancer risk in the group with the highest soy consumption.[12] Furthermore, studies on soy intake and prostate cancer risk in men have found anywhere from a 20% to a whopping 70% reduction in those with higher soy intakes.[13] I should note that dairy, on the other hand, may actually increase prostate cancer risk.[14]
While soy clearly doesn’t have a negative impact on hormones or cancer, there may be other reasons to consume soy products as well. Just ½ cup of whole soybeans contains 16 grams of protein, 5 grams of fiber, over half your daily requirement for iron, and significant amounts of magnesium, copper, and manganese. This makes soy the highest protein legume, with 37% of its calories coming from protein! In addition, it contains significant amounts of many B vitamins and vitamin K. Even though tofu is somewhat processed and removes some of the fiber and minerals, soy is so packed with nutrition that it is still quite a healthy food.
Soy protein intake has also been shown to reduce cholesterol levels, which helps reduce cardiovascular disease risk. On top of that, soy reduces inflammation, which is a contributor to just about every chronic illness we know of.[15]
The American Academy of Pediatrics also suggests that a soy-based formula is the nutritional equivalent of cow’s milk formula and is suitable for full-term infants with no evidence of hormonal effects.[16]