Casein Protein Reviewed: The Best Timed-Released Protein?

Casein protein has achieved a prominent place in the bodybuilding world. I'm sure you've already seen terms like "timed-release," "anti-catabolic" and "micellar" being thrown around in various ads—which certainly make it look like a pretty desirable protein to add to your diet. What's it all about?

To begin with, casein supplements may seem pretty cutting edge and high tech, but casein itself is an old friend.

You'd have to be living in a cave to not be familiar with it, at least in food form. Most people eating a Western diet consume some on a daily basis, in the form of milk, cottage cheese, yogurt and hard cheeses, as well as in many prepared foods that include it as an additive.

Casein is a highly nutritious protein, although how it ranks compared to others depends on the scale being used. For example, it has a Biological Value (BV) of 77—lower than the reference protein, egg, which has a BV of 100. On the other hand, it has a Protein Digestibility Corrected Amino Acid Score (PDCAAS) of 1.0—the same as egg and whey proteins. But whichever way you rank it, casein can help out when it comes to getting high quality protein for building muscle.

But is that all there is to it?

Nope—casein actually has some interesting, and potentially valuable attributes beyond simply being a good source of essential amino acids. For one thing, it has anti-catabolic properties—that is, it reduces muscle protein breakdown. In one study, a 30 g "meal" of casein consumed after an overnight fast reduced whole body protein breakdown by 34% over a 7 hour measurement period. This was in marked contrast to whey protein, which had little effect.

Why?

It's because whey protein is digested very quickly and provides only a short-lived burst of amino acids; whereas, casein forms a sort of "gel" in the stomach that digests very slowly. Consequently, amino acids appear in the blood stream at a lower, but steadier rate. Casein, in effect, functions as a sort of "timed release" protein. This is why many bodybuilders use it as a "bedtime snack"—as it can mitigate the breakdown of muscle protein that occurs during sleep.

Casein is also a source of bioactive peptides that are released during digestion. Cultures used to produce dairy products such as yogurt, kefir and cheese also produce them. Casein peptides have been identified that can reduce blood pressure, function as carriers for minerals, stimulate the immune system, and inhibit the growth of tumor cells. So casein may have a variety of health-promoting properties in addition to its nutritional value.

Are there any downsides to casein?

Sure: casein is potentially allergenic, although most milk allergies are formed during early childhood. There is also some controversy over the health effects of genetic variants of b - casein. Specifically, there are two variants that have been identified: A1 and A2. There is some evidence that implicates consumption of milk containing the A1 variant with increased risk of atherosclerosis and type 1 diabetes. The data is not conclusive, however, as other researchers have either criticized the methods used in these studies, and have not found any direct evidence for atherosclerosis risk in humans. The issue has yet to be settled.

I personally don't worry too much about either issue, however. Despite dark suspicions raised about milk proteins by various health activists, if you have not developed an allergy to milk proteins by the time you're an adult, you're highly unlikely to. In this, casein is no different than other common food allergens. And the increased risk of atherosclerosis from A1-b - casein is still far from proven. In my humble opinion, the benefits of casein for building lean body mass and strength outweigh the limited risks.

Supplemental casein is available in several different forms. Commercial casein protein powders use either caseinates or micellar casein. Caseinates are casein salts. Caseinates are made from casein that's acidified and precipitated at pH 4.6 (mildly acidic), then treated with alkali, usually in the form of sodium or calcium hydroxide. Micellar casein is produced by ultra- or microfiltration, which preserves the structure of the casein micelles. Which kind should you look for? Micellar casein is presumed to be the "gold standard" for supplemental casein protein, but it's expensive, chalky-tasting and difficult to mix when consumed straight (I know, I've tried it). By contrast, caseinates are more soluble, better tasting and easier to handle.

Casein is also available in the form of milk protein isolate (MPI) and concentrate (MPC). Since these are isolates made from total milk protein, they are—in effect—casein/whey blends, which have the same proportion of each as is found in the original milk (i.e., 80% casein and 20% whey). There is some evidence that the blend of the two proteins together is superior to each one alone. A comparison study revealed that total milk protein had the "best nutritional quality" and lower rates of deamination/conversion to urea than either micellar casein or whey protein in human volunteers. The researchers suggested that this was due to synergistic effects between the two.

So what to buy...???

There are a huge number of commercial options, ranging from straight casein powders, to milk protein isolates/concentrates, to whey/casein blends. Check out the list at the bottom of the page for some of the options available.

But is it necessary to buy a special powder to get the benefits of casein? Not at all...you can go straight to the source and buy some plain old milk. Ditto ultrafilitered milk (for the carb-conscious) and cottage cheese. Fermented milk products such as plain yogurt or kefir also offer casein at a reasonable value, with the addition of valuable probiotic bacteria, too.

These are options that will fit most budgets and tastes, so unless you're already allergic or a vegan, casein is a worthwhile addition to any muscle building diet.

Have you used Casein?
Tell me what you think!

Casein protein is available at BodyBuilding.com!

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