What is casein, and how does it relate to nutrition?
The reason why I ask is because here in Argentina, a popular brand of milk called La Serenisima has released a new milk with extra calcium and extra casein.
What do you think?
-- Maria (last name withheld) Buenos Aires, Argentina
Casein is the main protein in milk (80% of protein in the dairy beverage is in the form of casein; the remaining 20% consists of whey.)
The only way it relates to nutrition is that, just like all other animal proteins -- and soy -- it is complete, meaning it provides all eight essential amino acids.
Although casein is highly bioavailable (the technical term for "the body wastes very little of it,") it is beaten out by egg albumin and whey protein.
I am not sure why a company would look to create "high casein" milk, particularly since casein is by no means an essential nutrient.
It is perfectly plausible to meet all your protein and nutrient needs without ever ingesting any casein.
Perhaps "extra casein" is their snazzy terminology for "extra protein," which I still do not see the necessity for.
Milk is already a good source of protein (9 grams per 8 ounce/236 milliliter glass), and as far as I know, protein deficiency is not a health issue in Buenos Aires.
My thoughts? This is simply an inventive marketing strategy to boost milk sales.
While we're on the topic of casein, allow me to say a few more things.
Although a small percentage of the population (roughly 2 - 3 percent) is allergic to casein, that is very different from being lactose intolerant.
A casein allergy is an altered immunological response to a specific protein, whereas lactose intolerance has to do with the body's inability to lactose, the naturally occurring sugar in milk and other dairy products.
That said, keep in mind that casein is in a lot of non-dairy processed foods (and many cosmetic products) since it is a rather inexpensive binding agent. This is why people with casein allergis need to read food labels VERY carefully.