DefinitionThe soybean has been a part of the human diet for almost 5,000 years. Unlike most plant foods, the soybean is high in protein and is considered equivalent to animal foods in terms of the quality of the protein it contains.FunctionSoy in your diet can lower cholesterol. There are many scientific studies that support this conclusion. In fact, the U.S. Food and Drug Administration (FDA) agreed that 25 grams per day of soy protein, as part of a diet low in saturated fat and cholesterol, may reduce the risk of heart disease.Soy may also reduce symptoms of menopause and the risk of osteoporosis. Soy products may possibly prevent certain hormone-dependent cancers, including breast cancer, endometrial cancer, and prostate cancer.Food SourcesNot all soy protein products contain the same a