Micellar Casein The Protein With Staying Power

Tuesday, October 2nd, 2012

Proteins, along with carbohydrate and body fat, constitute the primary energy-providing nutrients of the diet. Proteins are one of a kind for many reasons – they include nitrogen, and they present amino acids that serve as building blocks for the development of new proteins. But not all dietary proteins are identical in their biological effects. An emerging notion in protein quality is that digestion rate has a significant impact on protein benefits in the body. This has led to the classification of proteins as either slow or fast. Several proteins are digested slowly, whilst others are digested rapidly and results in quite different results. Another critical factor that plays a part in the quality of a protein is the method of processing. In this regard, micellar casein has several special proteins that make it incredibly desirable as a protein supplement for sportsmen. Here, the benefits of micellar casein are overviewed and we recount some of the important results from studies analyzing the unique benefits of casein on protein stability.

Casein is the most abundant protein in milk.

Milk truly contains a variety of proteins, and due to numerous specific qualities is easily converted to a wide range of products such as cheese and yogurt. The amino acids in caseinare present in such a proportion to promote growth and development of the young. It has all the necessary amino acids, which makes it score well on all methods of protein quality. The other primary protein in milk is whey. Whey protein is more soluble in an acid setting, while individual casein molecules are fairly insoluble in the aqueous setting of milk. Due to the fact casein is insoluble it tends to form structures referred to as micelles. Micelles are suspensions of spherical structures that improve solubility in water. The casein micelle also contains water and a salt (usually calcium or phosphorus) in the core. Because of these particular attributes, casein has a significantly reduced digestion rate. In the course of regular treatment of milk, which usually involves heat or acid, the casein peptides and the micelle structure become disturbed or denatured. Simple put, the proteins are disrupted and shattered apart to less complicated structures. As {a|an} outcome a gelatinous substance is formed – the curd – and this is the basis for formation of products such as cheese. Micellar casein is undenatured, containing more of the undamaged peptides in their natural form. In order to maintain an abundance of micellar protein in the course of digesting, specialized treatment of milk has to be carried out. Because the casein micelle is in suspension, it can be separated from the rest of milk by centrifugation at a very high speed. One method to keep micellar casein is ultrafiltration or microfiltration. This prevents subjecting the proteins to heat, acid or other chemicals therefore conserving micellar casein. As a result, more bioactive peptides with immuno- and growth-modulating effects are present in the protein. Another important characteristic of micellar casein is that it is digested gradually, and therefore results in a slow yet constant release of amino acids into the circulation. The effects of this pattern of slow amino acid release has been researched in a number of studies and been shown to be pretty efficient at promoting an anti-catabolic environment for muscle mass development (1).

A first classic study documenting the effects of micellar casein on protein metabolism was done by French scientists and published in the prestigious Proceedings of the National Academy of Sciences (2). The researchers provided healthy subjects 30 grams of either whey protein or casein protein and made a number of measures of the anabolic and catabolic impact for 7 hours after the meal. What they discovered appeared to be that whey protein resulted in a rapid increase in blood amino acids and protein synthesis, but it was short-lived. Casein however resulted in a prolonged increase in blood amino acids that resulted in a 34% reduction in protein breakdown. The net protein stability continued to be better for the casein protein over a seven hour period. The authors attributed the superior long-lasting effect of casein to a postponed gastric emptying along with reduced assimilation rate from the gastrointestinal tract. These findings were quite innovative. Actually, a commentary has been written in the top science journal in the world – Nature, that went on to highlight the important aspects of how different proteins have various impacts on protein turnover (3).

To gain additional knowledge of these phenomena, scientists carried out more tests to document the effects of digestion rate of proteins on protein turnover. In the very first study (4), healthy young men have been given one of four meals:

  • a single meal composed of 30 grams of casein (separated by microfiltration and ultrafiltration),
  • a single meal made up of 30 grams of individual amino acids equal to the casein meal,
  • a single meal composed of 30 grams of whey protein, and
  • 30 grams of whey protein given in a sequence of 13 small meals given every 20 minutes.

In this case, Meal 1 and Meal 2 were both casein, but varied in digestion rate. Meal 3 was whey protein which is a fast-digesting protein. Meal 4 was whey protein, but the repeated ingestion resembled the characteristics of a slow digestion protein like casein. The results reinforced the importance of digestion rate on protein turnover. Meal 2 (free amino acids) and Meal 3 (whey protein), both fast-digesting meals, resulted in a larger increase in protein synthesis, but it was transient. They also resulted in a large transient increase in protein oxidation. Meal 1 (casein) and Meal 4 (repeated small whey protein), both slow-digesting meals, resulted in a smaller effect on protein synthesis, yet prevented protein oxidation and highly restricted protein breakdown. Protein equilibrium over the 7 hour period of measurements has been considerably higher with the slow-digesting meals. Thus, casein or small whey protein consumed frequently resulted in the most advantageous protein stability over a maintained period.

These studies show unquestionably that a slow-digesting protein, in these cases microfiltered and ultrafiltered micellar casein, is an independent regulator of protein retention. As a result micellar casein makes an perfect protein supplement to support extended periods of an anabolic environment for muscle development. This makes micellar casein especially desirable as protein supplement for such periods as prior to bed or any time regular meals cannot be consumed.

Leave a Reply