The soybean (Glycine max) is a member of the legume family. Although the soybean is native to southeastern Asia, more than 50 percent of the worlds soybeans are produced in the United States. Soy foods are rich in health benefits and provide a high-protein diet without the fats found in meats. Soybeans are also loaded with vitamins, minerals, fiber, isoflavones and essential fatty acids.
The quality of protein found in soybeans is considered to be equal with animal protein. A one cup serving of soybeans has more than 55 percent of the daily need for protein. This serving size has about 300 calories and 2.2 grams of saturated fat. Soy protein may also help lower blood cholesterol levels if eaten in large amounts. Animal protein sources usually raise blood cholesterol levels.
Besides being a source for healthy protein, soybeans also contain a large quantity of easily-absorbed iron. A one cup serving of soybeans has slightly more than 49 percent of the Daily Value for iron and 37 percent of the D.V. of magnesium. The essential omega-3 fatty acid in soybeans is more than 41 percent of the D.V.
Isoflavones are one of the active ingredients in soybeans that has been studied the most. These are weak forms of estrogen that mimic the body’s natural estrogen. This is the reason that isoflavones are also known as phytoestrogens.
Genistein is one of the isoflovone compounds that cause the body to produce fewer and smaller fat cells, resulting in an ability to stay leaner. There are several other healthful ingredients in soy that are believed to have anti cancer benefits. These are phenolic acids, phytic acid, phytosterols, saponins and protein kinase inhibitors.
Soy can be included in the diet with raw soybeans, soy flour, roasted soybeans, soymilk, and soy burgers. Soy burgers and other imitation meat products use T.V.P (textured vegetable protein) made from soybeans. The healthful isoflavones are not found in soy sauce and soy oil.
Techniques used to ferment the soybeans allow for easier to digest forms such as tofu, miso (soy paste) and tempeh. Tempeh is made from a fermentation process which forms the soybean particles into a cake form. Unlike tofu, tempeh uses the whole soybean and has a different texture and nutritional benefits. It has more dietary fiber, protein and vitamins than tofu. It is very popular in a vegetarian diet as a meat substitute.
According to the American Institute for Cancer Research, laboratory studies with soy have shown protective benefits against cancer in the cells and tissues of the lung, bladder, cervix and stomach. They also state evidence is beginning to show that a soy-rich diet might make cancer cells in the breast, cervix, ovary, head and neck more sensitive to the effects of chemotherapy and radiotherapy.
The phytoestrogens in soy can mimic the body’s hormones to a lesser degree. This is why the majority of cancer research involving soy has been with cancers relating to hormones, such as breast and prostate cancers. According to the American Cancer Society, high doses of soy could lead to a possible increase in the risk of estrogen-responsive cancers. These would include breast cancer and endometrial cancer.
This is the reason high dosage of soy in the form of supplements are not recommended. This recommendation is also true for other benefits of soy. The popularity of soy supplements have increased in the past few years. Using soy as a supplement has not been thoroughly tested, so many aspects of its efficacy are not known.
Studies have also shown that soy protein can help to reduce the bad cholesterol levels (LDL) and increase the good cholesterol levels (HDL). The American Heart Association did an extensive review of these studies. Their findings suggest that any benefits in reducing the LDL cholesterol only came from eating large amounts of soy.
To receive any of the healthful benefits, it needs to be ingested as soy protein and not as a powder supplement. Soy has also shown to be beneficial in helping to prevent osteoporosis and lung cancer. There are scientific theories as to how soy may possibly help to prevent cancer. Soy protein seems to slow down development of tumors rather than preventing them completely.
Studies are inconclusive as to how much cancer prevention soybeans have. Soy foods should be included in the diet for the simple reason they are a healthy food source, as are all types of legumes. The excellent fiber and protein in soybeans and other legumes can also help keep blood sugar levels stable.
