The sports supplement industry suffers harsher scrutiny from the media and the public than other sectors of the natural products industry because of its central focus on ergogenics and anabolics[1]. A true ergogenic/anabolic pushes you beyond your natural (and possibly legal) limits, so it can objectively improve athletic performance and physique, but not without inherent risks. Serious athletes understand this just as they understand that playing football might result in permanent disability. 

However a product that promises improved performance and physique but in reality was never designed to do so is equally risky. Even the reputation of whey protein isolate—the most nutritious, digestible and hypoallergenic protein known—teeters on infamy due to low-quality imitations of industry-leading products.

Whey isolate is immune-boosting and the finest rapidly assimilated protein ever invented.  Ultrafiltered whey protein concentrate is a feedstock for infant formula.  It’s intended to replace the gold standard of human nutrition—breast milk. Most who believe they’re allergic to dairy products do not react to whey protein isolate, or even to whey protein concentrates (see Table 1). However I have been astonished at how trainers, dieticians, and natural products retailers steer customers away from whey due to potential dairy sensitivities. Unless you’re buying unknown material from a no-name supplier this is generally rubbish.

Common milks including cow, sheep, and goat are composed of two protein fractions, casein (80 percent) and whey (20 percent). Think of cottage cheese—“curds and whey.” To make cheese the casein protein is coagulated and drained, leaving the liquid whey. Casein protein is responsible for most true dairy product allergies. Once casein is removed milk is less allergenic.

Manufacturers of high-quality products employ cutting-edge dairy science, with three to six levels of cold processing and filtration, including both ion exchange and ultrafiltration, to produce whey isolates. This reduces casein and lactose to insignificant levels. 

The small percentage of persons who remain sensitive to whey protein hardly ever reacts to whey peptide hydrolysate, which is whey isolate that is enzymatically “predigested."  Enzymatic hydrolysis breaks down proteins into peptides—units of ~2-80 amino acids.  Long protein chains typically trigger allergic responses, not peptides. 

However unknown or “bargain” brands of protein powder may contain lower-protein concentrates or even dried milk. Excessive heat treatment and/or poor storage conditions may lead to off-flavors from the degradation of milk fat and sulfur-containing amino acids. Consumers can react negatively to casein, lactose, or distasteful milk proteins in these products, whereas they would have exceptional nutritional benefits had they utilized a higher quality product. Unknown brands may cause serious allergic reactions in some persons, therefore confirming the misinformation previously fed to them.  A customer is lost and a negative media spin is gained. 

Table 1.  Representativecomposition of dried whey products.  WPC = whey protein concentrate   WPI = whey protein isolate  Lactalbumin = heat processed (denatured)whey protein extract.

Reference: Huffman LM, Harper WJ (1999).  Maximizing the value of milk through separation technologies.  J Dairy Sci 82, 2238-2244.

[1]Ergogenics cause objective, significant improvements in individual performance for trained athletes just by ingesting them Improvements can be exhibited in speed, jump height, endurance or agility.  Anabolics cause significant increases in muscular strength.