Over the years, you have heard all of the controversial statements regarding soy and soy products:
“Soy products contain phytoestrogens and they will negatively effect my hormone levels!”
“I’m a guy and if I eat soy my pecks will turn in to breasts!”
“Eating soy will increase your risk of cancer!”
The list of accusations goes on and on…
Here’s the truth: soy can be consumed in the form of a soybean, also known as edamame, as well as tofu, miso, tempeh, soymilk, yogurt, cheese, ice cream and even soy “meat” and dairy substitutes. Soy is super versatile and can be used in cooking and baking, it can even be used to make a delicious cake icing – have you tried the Adonis cake!? In general, it is always best to consume the most minimally processed foods because they retain the most nutrients. Since soy is a widely consumed plant food, people often wonder just how beneficial soy is for your health. So, is soy your friend or your foe?
When it comes to male hormones, cancer prevention, fertility, thyroid health, and fibrosis, there is a lot to be said about soy. Studies show that soy products have NO negative effects on men’s health, and may even help to prevent cancer in men. Research recently published in the American Journal of Clinical Nutrition shows that an increased consumption of soy resulted in a 25% reduction of prostate cancer risk in men. A 30% risk reduction was recorded when non-fermented soy products, such as tofu and soymilk, were consumed. Men consuming soy products have been found to have lower overall risks of prostate cancer and better rates of prostate cancer survival. Soy products are made up of “weak” plant estrogens, called phytoestrogens. Phytoestrogens inhibit the natural estrogen produced in the body from attaching to cells. Natural estrogen typically latches on to receptor proteins in cells that allow for alterations in the chemistry of cells. So, research suggests that when phytoestrogens are present in cells, estrogen is not. These phytoestrogens have not been found to effect hormone levels, fertility or development in men and boys.
The presence of soy in the diet has been known to reduce the risk of prostate, colon and breast cancers. A California-based study conducted in 2008 found that women consuming one cup of soymilk or one-half cup of tofu per day have a 30% lower risk of developing breast cancer compared with women who consume little to no soy. In women who have already been diagnosed with breast cancer, consuming soy products proves to be a great advantage. By doing so, those affected have shown to reduce their risk of cancer reoccurrence by half! Studies cited in the Journal of the American Medical Association, as well as at Kaiser Permanente have yielded similar results.
When it comes to questions about fertility and reproduction, soy does not harm reproductive health. In addition, studies show that adults who were fed soy formula as infants do not differentiate in reproductive health than adults who were fed cow’s milk formula.
Clinical studies show that consuming soy products cannot cause hypothyroidism. Hypothyroidism is a condition in which the thyroid gland does not produce enough of the thyroid hormone, which is responsible for metabolism regulation. While the soy isoflavones do take up small amounts of the iodine used by the body to make thyroid hormone, the same can be said of fiber supplements and certain medications. However, iodine is found in an abundance of plant foods, especially seaweed.
Consumption of soy products have also shown to reduce the risk of fibrosis, a condition that occurs when balls of muscle tissue form within the thin muscular layers underneath the uterine lining. In a study consisting of Japanese women, results show that the more soy consumed, the less likely it was to need a hysterectomy, showing that fibrosis was less prevalent. Compared to a study conducted in Washington, soy did not provide negative or positive effects, because the levels of consumption are much lower in the Standard American Diet than in the Japanese diet. Researchers have also found that most beneficial phytoestrogens, called lignans, are found in flaxseed and whole grains. The women consuming adequate amounts of lignans recorded less than half the risk of fibrosis, compared to women who typically did not consume these foods. So, while in this case the benefits of phytoestrogens to combat fibrosis comes from plant foods other than soy, the effects of phytoestrogens are widely beneficial, and counter the effects of women’s naturally produced estrogen.
While the plant-based diet is largely anti-inflammatory, a study published in Shanghai Women’s Health, consisting of over one thousand middle-aged Chinese women, shows that the more soy consumed directly correlated to the less inflammation and inflammatory pain experienced. The presence of inflammation has been linked to cardiovascular disease, cancer and type-2 diabetes. Soy products are known to reduce low-density lipoprotein (“bad”) cholesterol, as well as the risk of hip fractures related to osteoporosis. The American Journal of Epidemiology published a study stating that women who consumed at least one-fourth cup tofu (less than one-half block) per day reduced their fracture risk by 30%!
Overall, the benefits of soy products are extensive and yield very positive results. However, these results are related to the consumption of traditional soy products, as opposed to concentrated, processed, soy proteins, powders and supplements. Stick to the good stuff, like tempeh, miso, tofu, edamame and soymilk. Soy is palatable, versatile and delicious, and will soon become your best friend. And guys, it’s good for you, too! Check out some of the great recipes featuring tofu and soy products in My Beef With Meat, Forks Over Knives, and Engine 2 Diet!