Naturally micellar casein is one of the principle proteins found in milk. The word ‘micelle’ is a term used in chemistry which refers to a complex structure of molecules which remains suspended in water. In this case the structure consists of amino acids. Amino acids are nitrogen containing, carbon-based organic compounds which are the simplest unit of protein.
Whey protein is the other main protein found in milk, but as it’s so small it does not form micelles. As casein is much larger its molecules aggregate together in water to form a micelle. Micellar casein is the natural structure of casein in milk and is comprised of the different types of casein: alpha-, beta-, gamma-, delta- and kappa caseins as well as some minerals including calcium and phosphorus.
Until recently casein micelles couldn’t be isolated from milk whilst being kept intact, so casein protein supplements were simply inferior, non-micellar forms. However, micellar casein has actually been used unknowingly as a sports supplements for years as part of milk protein supplement formulas.
Micellar casein is casein in its natural structure; if you see the terms ‘casein’ and ‘caseinates’ on ingredients lists these refer to the non-natural, less bioactive forms. Supplement formulas which contain the natural, bioactive form will be labelled as containing either ‘micellar casein’ or ‘milk protein’ on their ingredients lists: these are the only terms which apply to the natural form. Always, check ingredients lists to make sure you’re buying a quality product.
The main benefit of micellar casein is that it is casein in its natural form and our digestive systems have evolved to deal with natural forms better. The peptidase enzymes which digest proteins in the stomach act readily on the casein micelles and provide the materials for hormones, the immune systems, mineral absorptions and muscle growth.
Because it’s slowly digested, micellar casein is a great inclusion for bodybuilders especially for those periods where you’re likely to be going some time without protein intake, like bedtime or if you’re a shift worker. Side effects are few as it’s merely a natural foodstuff, but if you consume too much in one go you may experience temporary bloating.
If you have intolerance to milk or dairy products then casein should be avoided. It’s also a good idea to consume micellar casein protein powders directly after mixing them as, if allowed to settle, they can get rather thick.