HOW TO READ A  PROTEIN LABEL
Whey protein is the number one choice of athletes for good reason. Not only does it result in the greatest retention of protein in muscle (i.e. highest bioavailability or BV); it also confers many health benefits (Bounous 1982, 1983, 1985, 1989, 1991, Birt 1982). However, because of the multitude of Whey products on the market, the consumer must become educated with regard to what constitutes a quality whey product or they may end up purchasing an inferior whey protein based on hype and not scientific fact.

Commercial whey protein comes from cows milk. If manufacturers simply concentrated the protein from cow's milk (by removing the fat, lactose, moisture and ash) its bioavailability would not rival that of well processed whey protein. The reason for this seems to be that cow's milk contains different ratios of protein "fractions" than human mother's milk. Each fraction is just a protein of similar shape and size made up of chains of the same amino acids. Because each fraction is unique, each has a specific role to play in protein metabolism. Recent technology (including "cross flow", "Micro" and "Ultra" filtration and "Ion Exchange" methods to concentrate whey protein) allows manufacturers to minimize unwanted fractions while maximizing important fractions. The following chart compares the major proteins of cow's milk and human mother's milk...
 

          (Comparison from Forsum 1973, Jennes l982)

Casein
This protein has only about half the bioavailability of a high quality whey protein concentrate (it would therefore result in about half the protein being retained in the muscle). Whey proteins do not contain casein unless it is added to the product.

Beta-Lactoglobulin
Human milk has virtually none of this fraction (Forsum 1973, Jennes 1982). Unfortunately, because it is the main constituent of bovine (cow's) whey, it can only be minimized. High quality whey protein will have about 50% of this fraction and it is a good source of amino acids (the building blocks of protein) and has a high Net Protein Utilization (a measure of the maintenance and growth properties of protein) but it should be minimized for many good reasons...

1) The most important reason is that if the level of Beta-Lactoglobulin is high, there is little room left for the more important fractions of whey

2) It is the most hyper allergenic fraction of whey protein (the most likely to cause allergic reactions)

3) It is easily heat denatured (when subjected to heat, its amino acids form tighter bonds making the protein hard to absorb)

4) It has a lower Protein Efficiency Ratio or PER (a measure of the growth-promoting capacity of protein) than Alpha-Lactoglobulin (Forsum 1973, Hall 1997).

Alpha-Laetalbumia
This is the major whey protein fraction of human mother's milk and it has the highest PER. The most thorough processing methods result in concentrations of over 20% (Forsum 1973, Eigel 1984). Don't settle for any less!

Glyco Macro Peptides or GMP (a component of proteose-peptone)
Most whey proteins contain none of this fraction either because they were produced using inferior raw whey or because they used economical processing methods (or both). Without this fraction, the ideal digestive and enzymatic environment to absorb whey protein cannot exist. Some companies will add cheap enzymes like bromelain to their product to try to make up for the fact that they have no GMP but GMP signals the digestive system to make a variety of accommodations to enhance protein digestion. GMP also has potent anti-viral properties to help combat colds and the flu (Hall 1997).

Other Fractions
Other important fractions are Serum Albumin and Lactoferrin. These are high in cystine (the stable dipeptide of cysteine) and glutamylcystein which provide most of the health promoting properties of whey. Whey protein's health properties include...

1) better outcomes for AIDS and cancer patients

2) increased life span of lab animals by 30%

3) the detoxification of at least a dozen environmental carcinogens

4) increasing glutathione (one of the body's most potent antioxidant) (Bounous 1997).

If a company does not list the method of processing and/or the protein fractions of the whey protein(s) on their label it is most likely because they are using outdated or inferior processing or have inferior ingredients. Some companies may have more than one whey product on their label. If so, they should give this information for each and not just one of the whey proteins on their label.

Hydrolyzation
Adding a hydrolyzed or predigested whey can result in a more rapidly and thoroughly absorbed protein (Poullain 1988, Meredith 1990). However, if the processing method and fractions are not given, it is probably a hydrolyzed whey protein concentrate with relatively low bioavailability. Check the label carefully to ensure that it has been enzyme hydrolyzed (not acid or heat hydrolyzed which results in a denatured protein).

Glutamine
Because whey protein is only about 5% glutamine, the addition of this amino acid will be of benefit. Glutamine peptides (short chains of glutamine) are more likely to pass through the gut intact (and therefore a greater amount will make it to the muscle), while L-glutamine (free form) is more concentrated. It is arguable which form is superior. Glutamine is the most abundant amino acid in muscle, has been shown to greatly increase growth hormone, is associated with cell volumnization and increased protein synthesis, and supports greater immune function (Welbourne 1995, Lacey 1990).

Recommendations

• Check the label carefully for the processing method(s) such as cross flow micro filtration, ultra filtration and ion exchange. The more methods the manufacturer uses, the better the result (Multi stage processing is more expensive but it is done for good reason).
• Beta LactoglobuUn can be minimized to around 50%.
• The higher the Alpha-Lactalbumin, the better (over 20%).
• Glyco Macro Peptides should be maximized (over 10%).
• Added glutamine will be of benefit.
• Some hydrolyzation wll assist in absorption.

Whey protein products with complete processing and fraction information on their labels include: Prolab's Whey, Precision Protein, Vyo Pro, and Labrada Pro Plex.
 

Mark Gilbert B.Sc., OFC/CPTN, STFA