Soy protein is a protein isolated from soybean and soybean is the only vegetable food that contains all the eight essential amino acids. Soybeans contain nearly 40 per cent proteins, 20 per cent fat, 35 per cent carbohydrates and 5 per cent minerals. It is a rich source of vitamin A, D, E and has appreciable amounts of B-group vitamins and minerals like iron, copper, zinc, magnesium and phosphorous and contains high amounts of phytoestrogens. It is very low in fat, contains no cholesterol and contains phytochemicals. The main phytochemicals in soy protein are isoflavones, saponins and phytic acid. These phytochemicals are strong antioxidants but have many other properties. Soy protein and its associated phytochemicals seem to reduce heart disease, osteoporosis and risk of cancer. Soy protein is used in a variety of foods such as salad dressings, soups, beverage powders, non-dairy creamer, frozen desserts, breads, breakfast cereals, pastas and pet foods. According to a report, soy protein is a diet, low in saturated fat and cholesterol promotes heart health. The report says that the daily consumption of more than 25g soy protein, with its associated isoflavones could improve lipid profiles in hypercholestrolemic humans. The large number of amino acid composition in soy products, in particular phytoestrogens, has been associated with lowering blood lipids. Studies have proved that isolated soy protein, if fed to individuals result in reduction of 10% total cholesterol.
Research suggests that consuming soy protein and the replacement of animal protein with plant protein may protect against osteoporosis. Epidemiological studies suggest that soy protein may reduce the risk of certain cancers, including breast cancer and prostate cancer. Japanese women, who eat a lot of soy protein, are at a much lower risk of developing breast cancer or prostate cancer than western people. The anti-cancer effect of soy protein could be explained by the phytochemicals, which are associated with the soy protein. These phytochemicals include isoflavones (genistein, daidzein and glycitein), phytic acid and saponins. Isoflavones and phytic acid have strong antioxidant properties and can prevent oxidative damage by free radical to ourDNAand cells.
Soy reduces the menopausal and post-menopausal symptoms and slows down the bone loss in post-menopausal women and being rich in fibre and low in glycemic index helps in weight management. Regular consumption of soy products adds to the chances of having a normal delivery and also provides necessary vitamins and minerals to the expectant mother. They are good for the overall health of the mother and baby. Soy helps increase the nutritional value of other foods and boosts the immune system as well. The Food and Drug Administration (FDA) officially recognised the cholesterol-lowering effects of soy protein in the year 1999. In the past 15 years, soy foods have attracted the attention of research scientists around the world for health properties beyond basic nutrition as well.