Download The Nutritional Profile of Soybeans

The Nutritional Profile of Soybeans
Our Japanese meal uses several soy-based and soy-derived foods today. The
macronutrient profile of soybeans differs in some important ways from most other
legumes. Soybeans are higher in both protein and fat than other beans and are
relatively low in carbohydrates.
Soybeans derive about 35 to 38 percent of their calories from protein compared to
approximately 20 to 30 percent in other legumes. It's amino acid pattern is also closer to
human protein than many other legumes, and hence very high quality, about the same
quality as meat and milk protein.
Soybeans are also, like peanuts higher in fat than many other legumes--- 40% of their
calories derive from fat by comparison to other legumes which typically range from 214% fat. The fat is 63% unsaturated (primarily linoleic acid), 23% monounsaturated
(oleic acid) and 14% saturated fat (primarily palmitic acid). It also contains 7% linolenic
acid, an omega 3 fatty acid.
Soybeans are also the richest source of legume isoflavones. Isoflavones are
phytoestrogens but are substantially weaker than estrogen. The main isoflavones in soy
are genistein and daidzein. By binding to estrogen receptor sites in the body, genistein
and daidzein block estrogen from binding. Since high blood levels of estrogen are an
established risk factor for breast cancer; weaker forms of estrogen may provide
protection. Genistein has been found to hinder breast cancer as well as prostate cancer.
Results from a new University of California study show that genistein slowed prostate
cancer growth and caused prostate cancer cells to die.
Because of their estrogen-like effect, genistein and daidzein also support bone strength
by stimulating bone formation and inhibiting bone resorption.