Soybeans 101: Nutrition Facts and Health Effects

Soybeans or soya beans (Glycine max) are a type of legume native to eastern Asia. They are an important component of Asian diets and have been consumed for thousands of years. Today, they are mainly grown in Asia and South and North America.
In Asia, soybeans are often eaten whole, but heavily processed soy products are much more common in Western countries. Various soy products are available, including soy flour, soy protein, tofu, soy milk, soy sauce, and soybean protein oil. Soybeans contain antioxidants and phytonutrients that are linked to various health benefits. However, concerns have been raised about potential adverse effects. This article tells you everything you need to know about soybean protein.

Protein
Soybeans are among the best sources of plant-based protein. The soybean protein content is 36–56% of the dry weight. One cup (172 grams) of boiled soybeans boasts around 31 grams of protein.
The nutritional value of soy protein is very good, although the quality is not quite as high as some animal proteins. The main types of soybean protein is glycinin and conglycinin, which make up approximately 80% of the total protein content. These proteins may trigger allergic reactions in some people. Consumption of soy protein has been linked with a modest decrease in cholesterol levels.

Fat
Soybeans are classified as oilseeds and used to make soybean oil. The fat content is approximately 18% of the dry weight — mainly polyunsaturated and monounsaturated fatty acids, with small amounts of saturated fat. The predominant type of fat in soybeans is linoleic acid, accounting for approximately 50% of the total fat content.

Carbs
Being low in carbs, whole soybeans are very low on the glycemic index (GI), which is a measure of how foods affect the rise in blood sugar after a meal. This low GI makes soybeans suitable for people with diabetes.

Fiber
Soybeans contain a fair amount of both soluble and insoluble fiber. The insoluble fibers are mainly alpha-galactosides, which may cause flatulence and diarrhea in sensitive individuals. Alpha-galactosides belong to a class of fibers called FODMAPs, which may exacerbate the symptoms of irritable bowel syndrome (IBS).
Despite causing unpleasant side effects in some people, soluble fibers in soybeans are generally considered healthy. They are fermented by bacteria in your colon, leading to the formation of short-chain fatty acids (SCFAs), which may improve gut health and reduce your risk of colon cancer.