The missing piece: Whey protein’s role in the immunity jigsaw puzzle

Whey protein is known for its role in protein synthesis and weight management, but it is also a bountiful source of key macro- and micro-nutrients that deliver immunity benefits.

Robert Child
Robert Child Director of the nutrition consultancy Alimentarius
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Published: Jul. 23. 2020

Rarely has the demand for foods and nutritionals that benefit immunity been stronger. The coronavirus pandemic has led people all around the world to reach for products that are rich in compounds known to boost their immune systems. For example, growing demand for products rich in vitamin C, as well as interrupted supply chains, resulted in a temporary orange juice shortage during March. But while other nutritionals have hogged the spotlight, including, zinc, vitamin C, iron, bioflavonoids, and carotenoids, one that rarely features in the immunity discussion is whey protein. 

A key part of the puzzle
People tend to think of whey protein in terms protein synthesis and weight management, but rarely in terms of its benefits for the immune system. This is unfortunate, as whey protein can play a role for disease prevention in the general populations and professional athletes, as well as helping in chronic disease management. It also has massive potential in infant formula, where it provides an excellent foundation to support growth and immune health. 

There is plenty of in vitro research available into whey protein’s inhibition of viral adhesion, which directly impacts the risk of infection. In addition, sialyloligosaccharides, which are naturally present in human milk and whey protein, can act “as soluble receptor analogues for rotavirus, influenza virus A, B, and Escherichia coli with S-fimbriae (Kawakami, 1974; Dai et al., 2000).”

One of the great things about whey protein is that it contains a multitude of immune modulating components. This means that it is quite unique place to benefit multiple aspects of the immune system simultaneously. While whey protein is not a totally complete food for immune system support – it lacks efficacious amounts of vitamin C and zinc – it does provide a large and forgotten part of the immunity jigsaw.

Whey protein: A powerhouse for immunity
Whey protein is a bountiful source of key macro- and micro-nutrients that deliver immunity benefits:

Immunoglobulins: These active components, which are resistant to digestion, account for about 10 percent of the protein in whey. They are involved in multiple aspects of immune function, stimulating immune cells, neutralising viruses, and bacteria; making them particularly relevant in the current situation. One key aspect of their mechanism of action is in preventing the adhesion of microbes to the mucosa, which is event that viruses require to cause infection. Immunoglobulins help to quarantine viruses outside of the cell, reducing their chances of successful colonisation and becoming sick. 

Glutamine: Whey protein is an excellent source of amino acid compounds with immune benefits. Glutamine, which accounts for about 30 percent of the total amino acid content of whey protein, serves as fuel for the immune system and cells. For example, a study on long distance runners found that taking glutamine immediately after exercise reduced the risk of illness in subsequent days (Castell et al. 1996, Eur J Appl Physiol Occup Physiol. 73; 488-490). Studies on triathletes used a different approach to reduce infection risk and provided them with branched chain amino acids (BCAAs), which are also highly concentrated in whey protein (Walzem et al. 2002, Critical Reviews in Food Science and Nutrition. 42, 353-375). This approach resulted in 34 percent reduction in the incidence of infections, improved immune function and better maintenance of plasma glutamine levels. These benefits were achieved by supplementing with 6-9g of BCAAs per day, and this can easily be achieved by consuming around 30g of whey protein. 

Lactoferrin: Whey protein is also a good source of lactoferrin, a compound that has a significant role in iron binding and absorption. It also ensures that the iron is not available to harmful bacteria, thereby inhibiting their growth. While a lot of athletes are iron deficient due to their training regimen, this deficiency is also an issue in the general population. For example, around 20 percent of pre-menopausal women are iron deficient and about 3 percent of men. Iron is poorly absorbed from many foods, especially vegetables, however the presence of lactoferrin in whey could enhance iron uptake and help address iron deficiency.

Sialic acid: This compound reduces the adhesion of E. Coli and H. Pylori to cells in the gut. It therefore reduces the risk of these types of gut infections. As well as potentially decreasing infection risk, sialic acid has also been shown to have prebiotic effects, stimulating the growth of bifidobacteria and lactobacilli.

Casein-Macropeptide: This compound accounts for around 15-20 percent of the protein in whey. It has similar antibacterial properties to lactoferrin and has been shown to inhibit the growth of Streptococcus.

Beta-lacto-globulin: This compound accounts for about half of the total protein content in whey and is also potentially useful for boosting immunity. Beta-lacto-globulin may serve as a way to deliver amino acids to immune system function, rather than direct immunological effects, per se.

Selenium: Last but not least, whey protein contains a very well absorbed source of selenium, a micronutrient that is known to improve multiple aspects of immunity, including viral handling. In fact, there is growing discussion around the challenges European populations face in attaining acceptable selenium intakes. Research we conducted by in the late 1990s was some of the first to investigate the effects of whey protein on selenium status in healthy subjects (Child et al. 2003 Med Sci Sports Exerc. 35, S270). Healthy men were supplemented with 40g of whey protein each day, resulting in improved selenium levels and more durable red blood cells. While no tests were conducted on immune system functioning, the findings were positive and suggest that some of whey proteins benefits could be mediated by selenium. 

Secondary benefits: Although we have spoken on about specific compounds in whey that have direct benefits on the immune system, whey protein may also produce important “secondary effects.” For example, high levels of cortisol often arise from mental of physical stress, which is known to result in the death of white blood cells and immune suppression. This is a particularly common problem for athletes involved in high volume and high intensity training, such as endurance athletes. Since whey supplementation has been found to lower the cortisol response to stress, it could improve immune functioning by favourably affecting the hormonal environment.

More than protein synthesis
As mentioned in my last blog, there has been increased interest in whey protein. The COVID-19 pandemic has only accentuated the need for solutions to help people stay fit, particularly during a lockdown. But this demand for whey protein can largely be attributed to its’ protein synthesis benefits and potential for reducing body fat. Whey proteins rich content of immunity boosting compounds remain relatively unknown by many consumers and sports practitioners. This represents an untapped opportunity for many athletes to improve both their health and physical performance. 

As athletes ramp up their training volume and intensity in anticipation of competition, they will also increase their bacterial and viral exposure, from inspired air and food ingestion. International events will further enhance an athlete’s exposure to bacterial and viral pathogens, making staying healthy an increasingly difficult challenge. This will make the inclusion of immune boosting foods and bioactives in their diets a routine focus, particularly in more challenging situations when they are “on the road.” 

Maintaining immune health is not just an issue for professional athletes, for example businesspeople and even holidaymakers, will face immune challenges from stress and increased pathogen exposure. The new normal will increase the demand for immune nutrition and whey protein is likely to become an increasingly important and recognized component of the immunity jigsaw. 


This blog contains material and information intended for B2B customers, suppliers and distributors, and is not intended as information to the final consumers.

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This blog is a medium for all industry experts to share knowledge about and viewpoints on whey protein and lactose - and, in particular, their documented or potential benefits to the world.

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