Casein has long been one of the most popular supplements on the market, and is definitely one of the safest. In 1997, researcher Yves Boirie and his team declared Casein to be "the only anti-catabolic protein in existence", a claim which has not been challenged since (1). Why is this the case, and why do so many people use casein?
Casein – What is it?
Casein, like whey, is a protein derived from milk. Thousands of casein molecules come together and form tiny round structures called "micelles", centered around molecules of calcium phosphate. Micelles are too large to dissolve in water, and they float suspended amongst the other ingredients in milk. Just under 80% of all protein in milk is micellar casein (2).
Casein is a very high quality protein source. It is high in all of the essential amino acids, and muscle building BCAAs make up about 20% of the total content (3). In addition, Casein can stimulate the production of anabolic hormone IGF-1, and it is high in calcium, a strength and muscle builder which is invaluable to bone health.
Casein Beneficial Effects
Like other proteins, casein provides the amino acid building blocks for muscle growth. Casein's biggest positive attribute is the ability to release these amino acids into the body over very long periods of time.
While most proteins, such as whey, are broken down and absorbed quickly, the acid in the stomach causes casein to congeal into a large bolus, or clot, within the stomach. This is digested at a much slower rate, which means that a serve of casein can supply amino acids to the body for as long as seven hours. While there are a number of other slow digesting proteins, this is a feature unique to casein (1).
Casein at Night Before Bed
Casein is sometimes described as a night time protein, and before bed is a great time to take this long lasting source of amino acids. Catabolism, or muscle breakdown, is the enemy of bodybuilders, and to avoid this, it is important to maintain a positive nitrogen balance at all times. This does not exclude sleep, which is the time when the body repairs itself and lays down new muscle.
Long lasting casein is an ideal source of overnight amino acids, and will keep you going until breakfast.
Casein comes from milk, and as such, pure casein has a bland, benign flavour which is suited well to classic dairy flavours like chocolate and vanilla. It's not so much the flavour of casein that is noteworthy, but the texture, which is quite unique.
From "grainy" to "furry", many people have dreamed up a lot of unlikely adjectives to describe the way casein feels in the mouth. This unusual mouth feel is thought to be due to the insolubility of the casein micelles in water. Casein formulations are also, in general, a bit thicker than other proteins like whey. The taste and texture of casein is not unpleasant, but it is a bit different.
Casein – Good or Bad?
Casein is nutritionally complete, high quality, rich in muscle building ingredients, readily available, cheap, and has unique properties which allow it to release amino acids into the body over the course of many hours. While it is one of the safest supplements around, like anything else, it does have the potential to cause some minor side effects, like indigestion and acne, and some people have casein allergies.
Casein – Is it Worth It?
Everybody is different, and clever people know that an important part of maximising their gains is finding out personally what gets the best results for them. It would be an oversight for anyone serious about their physique to overlook casein in this quest.
Casein is a unique protein which performs a unique role, and you'd be hard pressed to find a better slow-acting protein.
To repeat the words of Yves Boiron - "The only known anti-catabolic protein in existence"? Sign us up!
(1) Boirie Y, Dangin M, Gachon P, Vasson MP, Maubois JL, Beaufrère B. Slow and fast dietary proteins differently modulate postprandial protein accretion. Proc Natl Acad Sci U S A. 1997 Dec 23;94(26):14930-5.
(2) Holt C, Carver JA, Ecroyd H, Thorn DC. Invited review: Caseins and the casein micelle: their biological functions, structures, and behavior in foods. J Dairy Sci. 2013 Oct;96(10):6127-46.
(3) Phillips SM, Tang JE, Moore DR. The role of milk- and soy-based protein in support of muscle protein synthesis and muscle protein accretion in young and elderly persons. J Am Coll Nutr. 2009 Aug;28(4):343-54.