I watched an interesting presentation from the 7th International Conference of Nutrition and Medicine that occurred July 26th-27th, 2019. Dr. Mark Messina mentioned that there are two types of estrogen receptors: alpha and beta. A stimulated alpha estrogen receptor causes all cells to replicate faster. Everyone has random cancer cells in their body at all times. This is a concern for cells in the breast. The faster the cells divide, the higher the risk of breast cancer. On the other hand, a stimulated beta estrogen receptor causes cells to replicate slower. The slower the cells divide, the decreased risk of breast cancer.
Soy-containing foods have compounds which look similar to estrogen. These compounds are called phytoestrogens. Phytoestrogens stimulate the beta estrogen receptor, causing cells to replicate slower. In fact, Dr. Messina was saying that there are studies that show people with breast cancer can live longer eating soya products than those who do not.
He recommended that healthy adults eat 2-4 servings a day of soya foods. Breast cancer survivors should eat less than or equal to 3 servings a day. He also recommended children and adolescents consume 1-2 servings a day. These recommendations are based on the research.
"A rough guide is that one serving of soy equals 1 cup of soymilk, or 1/2 cup of tofu, tempeh, soybeans, or soy meats. This is the rough equivalent of about 8 to 10 grams of soy protein and 25 mg of isoflavones."
He traced the origin of the concern about 'feminization' of men with soya back to an article in Men's Health magazine from 2009. Since the original story, Men's Health has acknowledged that soya is beneficial to men.
Finally, he refuted the belief that soy affects thyroid function. He backed this up with scientific studies.
I am going to start eating more soya in my diet. I will consume the soya in the whole-food form such as soya beans, edamame, tofu and soya milk. I will avoid the ultra-processed soy isolates and supplements because of the lack of the thousands of other compounds that are contained in the whole-food.