The ubiquity of conflicting ideologies concerning benefits and/or dangers of soy has caused much confusion, but is worth revisiting, especially by those in pursuit of optimum nutrition. A comprehensive investigation reveals the mysterious soy bean to be a great gift for the plant-based lifestyle. Thankfully, recent advanced research is available and sheds light on the following questions.
Does soy prevent or cause cancer?
Soy contains two isoflavones, genistein and daidzein, that mimic and affect naturally occurring estrogen in the body. These phytoestrogens bind to estrogen receptors, activating or deactivating the hormone. This is where breast cancer concerns have been raised. However, the estrogenic effects of genistein has been found to be either largely positive or neutral, depending upon levels of estrogen already found in an individual.
Furthermore, soy products are linked to prostate cancer prevention. The National Center for Biotechnology Information states that “soy foods and their isoflavones (genistein and daidzein) are associated with a lower risk of prostate carcinogenesis.”
How does soy affect natural hormones?
Evidence based on clinical trials has been found and reinforced that the isoflavones in soy do not have an adverse effect on thyroid function in humans. However, as with several herbs and drugs, it can interfere with the absorption of levothyroxine, a medication prescribed for underactive thyroid.
Based on the knowledge of phytoestrogens in soy, buzz surrounding the effect it may have on testosterone levels emerged. However, an analysis of 47 studies show that soy has no significant affect on the male hormones.
Does soy improve cardiovascular function?
After studies showed a marked decrease in bad cholesterol “LDL” among those consuming elevated levels, soy once again found itself in the examination room. More studies were conducted and scientists found that, where soy was replacing animal products, LDL (bad cholesterol) levels dropped and HDL (good cholesterol) levels rose. Conclusively, we know that a diet low in cholesterol and saturated fat will keep the heart healthy, which means that a plant-based lifestyle can and will do just that.
Why so much confusion?
It is important to note that the way in which soy is studied should be carefully considered. For example, early studies were conducted on rats which, we’ve learned, metabolize soy differently than humans.
Also, many studies have been conducted in Asian cultures where soy is already consumed at higher rates. These consumers seem to benefit from the product, however there is speculation that ethnicity plays a role in how soy is metabolized. Additionally, it is found that where more soy is being consumed, there is typically a lowered consumption of animal products, a practice known to lower risk of certain types of cancers and heart disease.
What are the known benefits of soy?
We know that the soy bean is of the legume family, containing all 9 amino acids, making it one of the few plant-based gems to provide a complete, quality protein. In addition, we find that soy is rich with B vitamins, fiber, potassium, and magnesium … all nutrients known for keeping cells healthy.
Overall, the research is staggering, proving benefits of soy practically eclipse perceived drawbacks, leaving us with another nutrient-dense, complete protein with versatility illustrating a favorite old adage: variety is the spice of life.