Although soy protein-based nutrition has been used during infancy for centuries in the Orient, the first use of soy formula feeding in this country was in 1909. In 1929, Hill and Stuart proposed soy protein-based feeding for infants.

Before the 1960s, soy protein-based formulas used soy flour, which imparted a tan color and nutty odor to the formula, and infants consuming it often had diarrhea and excessive intestinal gas. These features and symptoms were attributed to residual indigestible carbohydrates in the soy. Since the mid-1960s, a soy protein isolate has been used, reducing these concerns and greatly increasing acceptance of the product.

What does it do? Soy, a staple food in many Asian countries, contains valuable constituents, including protein, isoflavones, saponins, and phytosterols. Soy protein provides essential amino acids. When eaten with rice, soy provides protein comparable to that found in animal products. Soy is low in fat and cholesterol-free. The isoflavones in soy, primarily genistein and daidzein, have been well researched by scientists for their antioxidant and phytoestrogenic properties. Saponins enhance immune function and bind to cholesterol to limit its absorption in the intestine. Phytosterols and other components of soy have been reported to lower cholesterol levels.

The isoflavone genistein from soy isolated protein has been reported to inhibit abnormal angiogenesis, the growth of new blood vessels that, when abnormal, can contribute to the development of cancer. Isoflavones from soy isolated protein have also been shown to inhibit 5 alpha-reductase, the enzyme that activates testosterone in the prostate gland and other tissues. 5 Alpha-reductase inhibition represents a potentially effective therapeutic approach to benign prostate enlargement and male pattern baldness.

Isoflavones from soy isolated protein may reduce the risk of hormone-dependent cancers, such as breast and prostate cancer, as well as other cancers. One study of soy research found that 65% of 26 animal-based cancer studies showed a protective effect of soy or soy isoflavones. Human research also suggests a protective role of soy against cancer, but the data are currently insufficient to form any solid conclusions. A review of 38 different studies revealed that soy consumption reduced cholesterol levels in 89% of the studies.

Soy isolated protein may also be beneficial in preventing osteoporosis. Research shows that Isoflavones from soy isolated protein have protected against bone loss also can promote the development of bone cell. Improve building ability of the bone in studies. In a John Erdman Jr. at the University of Illinois's double-blind study of postmenopausal women, supplementation with 40 grams of soy protein powder per day (containing 90mg of isoflavones per day) protected against bone mineral loss in the spine and increased lumbar-spine bone density by 2.2 percent in six months.

Soy isolated protein has been used in connection with the following conditions:

• Osteoporosis
• High cholesterol
• Menopause
• Vaginitis