Casein is a slow digesting protein derived from milk.
In spite of its name, a canister of 100 percent whey protein may contain other ingredients, including sweeteners, anti-clumping agents and other types of protein. Because both whey and casein proteins are derived from milk, the milk must undergo filtration processes to separate the two proteins. Although whey protein is highly refined and filtrated, there can still be trace amounts of casein protein present in all types of whey protein. For those with food sensitivities and allergies, knowing the type of protein you’re consuming may make the difference between an extra protein boost, an upset stomach and a trip to the emergency room.
Casein Allergies and Whey
The Food Allergy Research & Education website recommends that those with casein allergies avoid whey protein in all its forms. Although it is best to obtain nutrients from a well-balanced whole food diet, you may consider supplementing your protein intake from non-dairy sources, such as soy, rice and hemp protein. If you do not have a casein allergy but are looking to monitor your casein intake, take a closer look at the types of whey protein available.
Twenty percent of milk protein is whey, with the other 80 percent composed primarily of casein. During the cheese-making process, both whey and casein proteins are separated from other milk constituents, then separated from one another. The final result is commonly referred to as “whey protein.” This process separates the majority of the casein protein from the whey, although trace amounts may still be detectable. To remove the casein - as well as lactose, other carbohydrates and fat - whey protein is further refined.
Whey Protein Concentrate
The second most refined form of whey protein is referred to as “whey protein concentrate.” This form of whey protein has undergone ultra filtration to further concentrate the whey protein by removing casein, lactose and ash. Once this process is complete, the product contains 25 to 89 percent whey protein, with most products coming in at 80 percent whey protein.
Whey Protein Isolate
When whey protein undergoes micro filtration and ion exchange, the result is the most highly refined whey protein product – whey protein isolate, which contains at least 90 percent whey protein. This filtration process further removes essentially all lactose and fat, making it safe for those with dairy sensitivities to consume. Although it is considered whey protein in one of its most purest forms, whey protein isolate is still not guaranteed to be free of casein.