I keep hearing about bioactive fractions found in whey, but I don’t know what they are and why they are important?

This is certainly an area of whey protein that researchers are feverishly working to understand more about. A great deal of research is out there explaining the importance of essential amino acids and their impact on recovery, muscle protein growth, etc.

You also have likely heard about different types of protein and how some of them digest at different rates and why this is important. All of these discussions often occur in the context of something that helps exercising people experience better recovery, improved development of muscle and improvements in their own body composition (Ha and Zemel 2003).

From a health perspective, though, a number of ingredients can be found in fairly high concentrations in various sources of protein, particularly whey protein. Collectively, they are often called bioactive whey components, simply because they are components of whey protein and they exhibit biological activity.

A numbers of these factors act on the immune system and as a result their ingestion is often viewed as a way to strengthen someone’s immune system. To people who are regularly stressing their bodies (in your case this is likely by working out), greater immune function is viewed as a positive thing and could potentially reduce the number of days in which you may be sick or dealing with some form of infection that may decrease your quality of training or keep you in bed altogether.

Interestingly, people who regularly exercise have been shown to be less prone to illness when compared to sedentary people (Nieman 2000). A fine balance, however, must be struck whereby too much exercise can suppress the body’s ability to fight infection. This is an important fact to consider as well if you live a fairly rough and tumbly life.

If you don’t get enough sleep, fail to regularly hydrate and eat an imbalanced diet, it stands to reason as well that when this is combined with the extra stress of regular exercise training, immune function may be negatively impacted. Typically, increases in inflammation result leaving the body more vulnerable to bacteria, pathogens and other critters that make your nose run, your chest congested, and achy all over (Nieman 2000).

For starters, whey protein contains a healthy dose of glutamine, an amino acid that is known to be depressed after stressful exercise. Glutamine is known to be a fuel source for immune cells (a good thing) and the amino acid can become conditionally essential (Buchman 2001).

This means that during times of stress the body can’t make enough glutamine and therefore adequate amounts must be supplemented from the diet. Upon hearing all this, it now may make more sense why glutamine content is oftentimes touted by whey protein manufacturers and currently manufacturing methods are trying to be discovered to further increase glutamine content.

Other nutrients that may favorably impact the immune system are lactoferrin and lysozome, which both work to help minimize and prevent both bacterial and viral organisms from going crazy inside your body (Walzem, Dillard et al. 2002). Other key compounds which are found in much higher concentrations are beta-lactoglobulin, which is the major sub-fraction found in whey proteins, typically around 40-45% of the proteins found in whey and beta-lactalbumin (Korhonen, Pihlanto-Leppala et al. 1998; Walzem, Dillard et al. 2002).

Additionally, whey protein provides high amounts of cysteine-rich proteins. Cysteine is an amino acid and high amounts of cysteine are thought to help produce key proteins related to antioxidant potential. It’s important to understand, however, that while some studies performed in animals and small laboratory petri dishes suggest these factors may have important functions, more research is needed, particularly on healthy and exercising humans, to determine to what extent their immune-enhancing effects are at work (Ha and Zemel 2003).

Two additional areas in which parts of whey proteins can also help with overall health relate to gastrointestinal health and with helping to stave off excessive production of free radicals and oxidative stress. For example, glutamine and other components (glycomacropeptides) have been found to possess prebiotic and/or probiotic activity (Walzem, Dillard et al. 2002).

In simple terms, enhanced prebiotic and probiotic activity are thought to help maintain overall health of the gut. Also, lactoferrin and lactoferricin, two major protein fractions found in whey help to inhibit the growth of bacteria and balance over oxidative functions inside the body.

In this respect, an increased functioning of the glutathione system, the body’s major antioxidant system, has been suggested as well. This suggestion has been tested where 30 days of supplementation with whey increased markers of antioxidant potential while also helping to minimize fatigue (Lands, Grey et al. 1999).

Finally, an interesting side discussion can be made regarding these health-related factors and how the preparation method of the protein can impact them. For example, hydrolyzed proteins are becoming widely popular and touted for their improved absorption and greater ability to deliver needed amino acids fast resulting in improved recovery and potentially greater adaptations to the muscle-building stimulus of resistance training.

Many methods of hydrolyzing as well as high heat processing (which is very commonly used in order to produce the cheapest product possible most efficiently), however, completely wipe out all of these active protein fractions. While some may view this as a negative, it all boils down to your intended goal or reason for supplementing with whey protein.

If you are more concerned with health, a high quality whey protein isolate would likely be better, while a hydrolyzed source may be preferred for someone who isn’t concerned as much with the potential health related functions that may result from these protein fractions but rather more concerned with optimal athletic/physique performance.

There is always new information being presented, but in my opinion, a possible best-case scenario may be a product that contains a blend of high quality isolate as well as hydrolyzed sources, that way you are sure to get the benefits of both kinds of protein. Regardless, a number of factors are found in proteins that are being looked at for their ability to help a person’s health in addition to how their body responds to exercise. As always, I’ll keep you updated!


  • Buchman, A. L. (2001). “Glutamine: commercially essential or conditionally essential? A critical appraisal of the human data.” The American journal of clinical nutrition 74(1): 25-32.
  • Ha, E. and M. B. Zemel (2003). “Functional properties of whey, whey components, and essential amino acids: mechanisms underlying health benefits for active people (review).” J Nutr Biochem 14(5): 251-258.
  • Korhonen, H., A. Pihlanto-Leppala, et al. (1998). “The functional and biological properties of whey proteins: prospects for the development of functional foods.” Agri Food Sci Finland 7: 283-296.
  • Lands, L. C., V. L. Grey, et al. (1999). “Effect of supplementation with a cysteine donor on muscular performance.” Journal of applied physiology 87(4): 1381-1385.
  • Nieman, D. C. (2000). “Is infection risk linked to exercise workload.” Med Sci Sports Exerc 32: S406-S411.
  • Walzem, R. L., C. J. Dillard, et al. (2002). “Whey components: millennia of evolution create functionalities for mammalian nutrition: what we know and what we may be overlooking.” Critical reviews in food science and nutrition 42(4): 353-375.