Soy Protein Vs. Whey Protein

Although soy protein has been used for centuries in Asia for both nutrition and medicine, sales and product development in the U.S. received a big boost in 1999 when the FDA allowed manufacturers to label soy protein products with information about its ability to lower cholesterol and reduce the risk of heart disease. Since then the number and variety of products containing soy protein have multiplied.

According to the protein digestibility test, soy scores a 1.0 out of 1.0. Whey protein scores 1.14 out of 1.0, but it gets labeled as 1.0 anyway. Thus, soy is highly digestible and comparable to whey. Additional studies in adults and children confirm this. Soy is also the most complete vegetable protein--making it a staple food--and it's able to improve the nutritional value of anything it's combined with. It is naturally high in calcium and isoflavones. However, soy does not contain all of the conditional and nonessential amino acids typically found in whey protein.

Because soy is not derived from milk, people who are lactose intolerant or have allergies can take advantage of a high quality non-dairy protein supplement that is available in many forms. Soy protein powder, like whey protein powder, is readily mixable into shakes. Common forms of edible soy protein are soy beans, soy milk, soy flour, tofu (soy bean curd) and miso (fermented soy bean paste). Soy protein is also available through soy burgers, soy cheese and soy yogurt.

Soy protein powders are generally more expensive than basic whey protein powders. The cost-per-scoop for three leading brands ranges from 67 cents to one dollar. The cost-per-gram-protein ranges from three cents to five cents, which is comparable to the high end of whey protein powders. With all of soy's heart health benefits and quality vegetable protein, the extra cost may be worth it.