What is Soy and How is it Used?
Soybeans are legumes that originated in East Asia, but are now being produced on a large scale in the United States.
Soy is used to make many different foods. Soybeans can be eaten whole, with the immature types being called edamame. Soybeans must be cooked, as they are poisonous when raw.
Soy is used in tofu, soy milk and various dairy and meat substitutes. It is also used in fermented foods like miso, natto and tempeh, which are commonly consumed in some Asian countries.
Over 90% of soy produced in the U.S. is genetically modified and the crops are sprayed with the herbicide Roundup, which may be associated with adverse effects on health (1).
Interestingly, whole soybeans are rarely consumed in Western countries. The majority of soy in the diet comes from the refined products that are processed from the soybeans.
Most of the soy crop in the U.S. is used to produce soybean oil, which is extracted using the chemical solvent hexane. Soybean oil supplied about 7% of calories in the U.S. diet in the year 1999 (2).
What remains of the soybean after the fat has been extracted is called soybean meal, which is about 50% protein. The majority of soybean meal is used to feed livestock, but it can also go through further processing to produce isolated soy protein.
Because it’s cheap and has certain functional properties, soybean oil and soy protein have found their way into all sorts of processed foods, so most people in the U.S. are consuming significant amounts of soy without even knowing about it.
Soy protein is also the major ingredient in soy-based infant formulas.