Whey is readily absorbed and assimilated by the body, so it provides essential amino acids quickly for use in muscle protein synthesis after training. Newer forms of whey protein are also highly palatable and easy for most people to digest.
The original commercial products contained a rather crude whey-protein concentrate that was often high in lactose, a milk sugar that causes gastrointestinal distress in many people. Now, however, whey comes in various, and purer, forms. Ion-exchanged whey is perhaps the purest, so pure that it mixes clear in fluids and is devoid of lactose. Even so, while ion-exchanged whey is useful for those who cannot tolerate most forms of protein supplements, it lacks the major bioactive peptides that distinguish whey.
Another type of whey processing called macro/ultrafiltration eliminates most of the lactose but preserves many of the valuable bioactive peptides. Unfortunately, it removes bovine albumin, which provides “cysteine residues” that act as precursors for glutathione, a key antioxidant and cell protector. The other major whey-processing method is called cross-flow filtration. It retains all essential whey active peptides while eliminating fat and lactose.
Beta-lactoglobulin and alpha-lactoglobulin constitute 80 percent of whey protein. The bioactive peptide portion of whey, which constitutes the other 20 percent, is so named because it consists of smaller proteins or peptides that can be absorbed intact through the digestive process and benefit the body.
Mainstream self-styled nutrition experts often decry the use of protein supplements such as whey, noting that most Americans can easily get more than enough protein simply by eating protein-rich foods, such as meat, fish, milk, eggs and so on. What they overlook, however, is that those seeking to lose bodyfat are often on limited-calorie diets, and a supplement containing no fat or carbs—and relatively few calories—can offer real advantages. Protein is vital in any diet because it maintains lean tissue. When lean tissue is lost, metabolism drops, virtually assuring a quick return of bodyfat.
Whey, and protein supplements in general, allow you to take in protein at regular intervals without having to prepare a meal. That’s a considerable advantage for busy people, who cannot find the time to sit down and eat a regular high-protein meal. Some studies show that pulse feeding of protein, or taking it in at intervals of 2 1/2 to three hours, provides a heightened anabolic effect in muscle, particularly in younger people.
Another advantage whey confers is those bioactive peptides. For example, lactoferrin, one bioactive whey peptide, binds with iron. Bacteria need iron to reproduce, and by tying up excess iron, lactoferrin provides antimicrobial activity. Lactoferrin also inhibits the absorption and penetration of bacteria into the intestinal wall. Another whey peptide, lactoperoxidase, mimics the actions of some white blood cells by producing reactive oxygen species, or free radicals, that actively destroy invading bacteria. That, by the way, is one of the good things free radicals do.
The various immunogobulins provided by whey boost immunity. Whey is also rich in glutamine, an amino acid that immune-system cells use as fuel. Animal studies show that whey provides protection against colon cancer, particularly that associated with eating red meat (usually overcooked or barbecued). Other studies show that taking 30 grams a day of whey promotes tumor regression in patients whose cancer has metasticized, or spread.
A recent study found that when isolated healthy prostate cells were first treated with isolated whey protein, the cell content of glutathione increased by 64 percent.1 That’s significant because glutathione is a major cellular and tissue antioxidant in the body, and oxidative processes are involved in the genesis of prostate cancer. Although this study had an isolated-cell design, the implication is that whey may protect against prostate-cancer onset by protecting prostate cells from oxidative damage due to increased glutathione content.
The immunoglobulins and other bioactive peptides may offset the decline in immunity that often accompanies an intense workout. Glutamine also plays a role in that scenario.
As you can readily see, whey is more than just a simple protein source. Its amino acid content is similar to that of human muscle. While it contains 26 percent branched-chained amino acids, including leucine, which is considered the most vital for initiating protein synthesis reactions in muscle, whey offers benefits that extend beyond its pure muscle-building applications.
1 Kent, K.D., et al. (2003). Effect of whey protein isolate on intracellular glutathione and oxidant-induced death in human prostate epithelial cells. Toxicol in Vitro. 17:27-33.
