Soy protein, technically speaking, is the storage protein that is in the soybean. The most important storage proteins in soybeans are called soy cotyledon storage proteins. These cotyledon storage proteins are the ones that are the most important for humans and human nutrition. Soy cotyledon storage proteins are extracted from the soybean by using water. When soybeans are processed and the soy protein is removed from the soybean, it is processed into three different types of protein rich products: soy flour is one, soy isolate is the second, and soy concentrate is the third.

Soy protein isolate is one of the most important forms of processed soy beans and soy protein. Soy protein isolate must have at least 90% of protein content. It is one of the most purified and most highly refined types of soy protein. The way that soy protein isolate is created is by taking defatted soy flour and removing its non-protein parts, such as the carbohydrates and the fat. Soy protein isolate has been touted as being a safe and healthy way to combat the risks of coronary heart disease. It has also been claimed that soy protein isolate can be used to help prevent osteoporosis, and to aid in combating certain types of cancers along with symptoms of menopause.

The FDA has approved the claim that, as the FDA says in its official documents, "25 grams of soy protein a day, as part of a diet low in saturated fat and cholesterol, may reduce the risk of heart disease." How can you get 25 grams of soy protein each day? Well, for example, one serving of soy milk, which is either 1 cup of soy milk or 240 mL of soy milk, has either 6 or 7 grams of soy protein in it.

However, in 2006 the American Heart Association did publish a study that says that soy isoflavones do not, as has been claimed, cut down on hot flashes in women during menopause. Also soy isoflavones do not help prevent prostate cancer, uterine cancer, or breast cancer. Due to this study, the American Heart Association no longer recommends that soy isoflavones should be used as pure health supplements. However, the American Heart Association does back the claim that soy products such as soy burgers, soy nuts, soy butter, and tofu are beneficial to heart health because they have high levels of vitamins, minerals, polyunsaturated fats, and fiber. Also, these products are low in saturated fat.

2. Whey protein

Whey protein is the name given to a large group of globular proteins that are taken out of whey. Whey is a by-product of cow cheese milk. Whey protein is a combination of three different proteins: beta-lactoglobulin (about 65% of whey protein), alpha-lactalbumin (about 25% of whey protein), and serum albumin (about 8% of whey protein). When it comes down to it, whey protein possesses the highest Biological Value of any other protein.

Whey protein is either lactose free or reduced lactose. Also, whey protein is full of different nutrients and essential amino acids. Each part of whey protein has enormous ability to fight diseases, and, even better, it is easy to digest whey. Sometimes, pregnant women are prescribed whey protein as a dietary supplement so that the developing baby can receive important amino acids. Also, bodybuilders and athletes use whey protein more than many other protein supplements in order to help with muscle development and to help out with injury recovery. Similarly, if someone has a reduced immune system or a degenerative disease, antioxidant levels can be improved with undenatured bioactive whey proteins.

3. Pea protein

Pea protein is a group of proteins that are removed from peas. Pea protein is similar to both soy protein and whey protein in its ability to help fight disease and to improve overall health. Pea protein is easy to digest and is commonly used as a nutritional supplement.