A “good” source of a nutrient supplies 10 to 19 percent of the recommended dietary intake for that nutrient, according to the U.S. Food and Drug Administration's definition. The daily recommended intake for protein is 46 grams for women and 56 grams for men. Soy milk qualifies as a good source of protein for both women and men.
Protein in Soy Milk
An 8-ounce glass of soy milk supplies anywhere from 7 to 12 grams of protein. Unlike most other plant-based proteins, soy contains all the essential amino acids, making it a complete source of this nutrient -- just like meat, fish and dairy. You can use soy milk in smoothies, with cereal, in recipes as a cow's milk substitute or on its own.
Benefits of Soy Protein
Unlike cow’s milk and other dairy products, soy milk does not contain lactose, which makes it a good choice for people who are intolerant of this milk sugar. According to a 2009 article in “American Family Physician,” soy is also beneficial for heart health, helping to lower cholesterol levels. The same article pointed out that countries in which soy foods are eaten regularly have lower rates of prostate and breast cancer. In addition, fortified soy milk can help vegans and lactose-intolerant people get the calcium, vitamin D and B vitamins needed for optimum health.
Much of the soybean crop grown in the United States is genetically modified. As a consequence, some nutrition experts, like Dr. Mark Hyman, recommend choosing only organic soy foods and products, including soy milk.