Soy protein is protein that have been isolated from the soybean cakes. It is prepared from soybean meal that has been dehulled and defatted. The dehulled and defatted soybeans are processed into three different kinds of high protein commercial products, known as soy flour, concentrates, and isolates. One of these kinds is what we call as the Soy Protein. Soy proteins have been used since long as an ingredient in a variety of foods due to its rich functional properties and benefits associated with it. Soy protein is isolated derived from soybeans and offers multiple health benefits, some of which have just moved into the beginning to be discovered. Soy proteins are made from soy beans, one of the best non-meat protein sources around for the vegetarian diet supplement. Soybeans contain 36 gm of protein per 100 gm, and there is almost no fat associated with the protein.
Sources of soy protein
The rich sources of Soy proteins include
Edamame: Edamame beans are soybeans harvested while they are still young before they begin hardening.
Tofu is one of the richest sources of soy proteins.
Soy Milk: Soy milk has gained popularity as a source of soy protein, as a normal dietary supplement.
Miso: Miso is a rich, salty soy paste used in Japanese cooking.
Soy Nuts: Roasted soy nuts are whole soybeans that have been soaked in water and then baked until they turn brown.
Soy Sauce (Tamari, Shoyu and Teriyaki): Soy sauce is the dark brown liquid made from soybeans well fermented.
Tempeh: Tempeh is a chunky, tender soybean product.
Textured Soy Protein: Textured soy protein (TSP) refers to products made from textured soy flour, textured soy protein concentrates and spun soy fibre.
Whole Soybeans: As soybeans mature in the pod, they ripen into a hard, dry bean, similar to other legumes that are taken directly as the whole soybean cakes.
What is soy isoflavones?
Isoflavones are polyphenolic compounds that are capable of exerting estrogen-like effects and due to this reason, they are classified as phytoestrogens. Phytoestrogens are plant-derived compounds with estrogenic activity. Legumes, particularly soybeans, are the richest sources of isoflavones in the human diet. Soybeans are the most common source of isoflavones in human food and the major isoflavones contained in soybean are genistein and daidzein. Soy isoflavones are heterocyclic phenols that are structurally similarity to estradiol-17beta and selective estrogen receptor modulators. Their actions at the cellular level depend on the target tissue, receptor status of the tissue, and the level of endogenous estrogen. Numerous studies and reports indicate that, because soy is high in isoflavones content, it can prevent illness and promote good health. Isoflavones are basically a class of phytochemicals.
Can it be given to thyroid patients and if yes what are the safe criteria?
Studies have revealed that in animals fed with soy protein, there is lower energy utilization and lower protein utilization as compared to the milk protein fed animals. Circulating thyroid hormone levels (T4) were lower following soy feeding. These test animals were rodents, and they were fed soy as their only source of protein. In another animal study, rats fed soy isoflavones did not demonstrate goitre formation or any such increased sensitivity to conditions that may lead to low thyroid hormone or iodine deficiency. Finally, in another animal study, rats fed soy had lower activity of an enzyme implicated in goitre. This enzyme is known as TPO- which is responsible for making thyroid hormone. Thus as per the following studies Soy did not have any extreme effect on thyroid, whereas no such evidences have been found for humans, as well.
A large number of clinical trials have been conducted under several conditions (eg, menopause, osteoporosis, breast cancer, heart/blood vessel diseases). It has been found that using a daily dose of soy isoflavones from 40 to 120 mg is the normal level intake for it. Whereas, for the suggested levels for thyroid people, it is still under research pattern to derive the concrete amount of intake. The level intake for thyroid patients may vary based on the history of their disease profile. Getting the thyroid hormone levels checked by the physician and intake of recommended levels would be beneficial in such cases.
Side effects of toxicity
Based on the Soy Dangers the Newest Research on Why You Should Avoid Soy had been conducted that reveals that soybean contains large quantities of natural toxins or anti-nutrients as well. It has the unfortunate side effect of soy denaturing the other proteins in soy that includes: natural toxins, phytoestrogens, drug interactions. As a caution with soy isoflavones, Soya beans must be cooked well, as they are poisonous when raw. Soy foods have also been found containing high levels of aluminium which is toxic in nature.
Although Soybeans and their associated products are generally found to be well tolerated. There have been Minor GI disturbances that have been reported in various studies. The National Toxicology Program (US Department of Health and Human Services) after a research has concluded that there is very minimal concern for developmental effects in infants fed soy infant formula. Certain recommendations have also been made in the similar field so as to avoid the intake causing any serious side effects.
Various group of animal studies have also shown adverse effects of the isoflavone genistein on the developing nature of female reproductive tract. This has yet not been proven in case of humans and is still under study. As per the clinical and epidemiological studies, it safe for an adult to intake only 15-25 grams of soy protein per day or 2-4 servings of soy food per day. Larger intakes can cause toxicity in body, which might reduce fertility in women, trigger premature puberty and disrupt development of fetuses and children.
