Historically, soy was never a significant part of the American diet, although soybeans were second to corn as the nation's most valuable crop. Soy beverages were a niche market with a small consumer base, mainly vegetarians and people with specific health needs, such as lactose intolerance. Today, that is no longer the case. Thanks to emerging popularity of the high-protein diet in the U.S., soy beverages are experiencing growing sales. These beverages have answered the demand for quality protein sources low in calories, and are inexpensive. Soy beverages also have benefited from scientific research linking soy consumption to low levels of cholesterol and reduced incidence of such ailments as breast cancer and osteoporosis. With the Food and Drug Administration's (Washington) 1997 endorsement of soy as a quality protein source, many consumers are attracted to the preventative health benefits of soy for long-term good health.
Soy beverages are a convenient way to include soy in the daily diet. Soy protein is a complete source of protein, meaning it contains all the essential amino acids the body requires. The naturally occurring presence of isoflavones helps control the growth and regulation of many different types of cells by affecting the activity of certain enzymes and the level of specific growth factors. Soy beverages may be fortified with the addition of calcium carbonate, vitamin A and trace amounts of manganese, phosphorus and magnesium. Additionally, fiber is being used to enhance the health benefits of soy.