In recent years, soy products have become increasingly popular, especially with vegetarians who use it for its high protein content. When opting to eat soy though, it is important to make sure that you are eating the right kind of soy and that you distinguish between the myths and the facts.
Many people are concerned about soy because it contains phytoestrogens, a group of isoflavones that mimic human estrogen and can block natural estrogen alter the menstrual cycle, disrupt the endocrine system, cause infertility, and increase the risk of breast cancer. However, the fact is that isoflavones can also have non-hormonal effects on the body that are very positive. They help regulate cell growth, which can safeguard against some cancers. There are many studies that associate soy with lower rates of breast cancer, especially in Asian populations. Studies show that Asian countries, which have diets rich in soy, have lower rates of breast cancer than western countries.
It is important to note that soy is classified into two main groups: fermented and unfermented. Unfermented soy foods like tofu and soymilk can be problematic because they contain phytic acid. Phytic acid’s structure enables it to bind to proteins, minerals, and starch, consequently lowering your body’s ability to absorb them. Thus, phytic acid can actually block the uptake of essential minerals such as magnesium, calcium, copper, zinc and iron. Unfermented soy can also inhibit the uptake of iodine — an important mineral that is used by the thyroid gland to produce hormones that help the body to regulate metabolism.
On the other hand, fermented soy from organic soybeans — found in miso, tempeh, natto and naturally brewed soy sauce —is actually beneficial for our health. The fermentation process adequately reduces the phytate acid of soy so that we can safely digest it and enjoy the beneficial properties. Fermented soy is also a good source of vitamin K2, which acts synergistically with vitamin D to play an important role in preventing cardiovascular disease, osteoporosis, dementia, and various types of cancer.