PT on the Net Research

Whey Protein: Not Just for Bodybuilders

Any trip to a supplement store will reveal no shortage of large tubs of powder with all sorts of fancy colors and eye catching words. There is no denying the popularity of protein powders - especially whey protein - as their lure has expanded outside the bodybuilding community to the general public who are looking for a quick protein fix. If properly selected, whey protein can be a very valuable supplement. However, if not correctly educated, any consumer can end up with a tub full of wasted money.

Whey Protein and Lean Body Mass

Whey protein is a type of protein derived from dairy products. (Cow’s milk contains about 6.25% protein with 20% being whey. The rest is casein.) It has the highest biological value (a measure of the ability of food protein sources to deposit nitrogen into muscle tissue) of any dietary protein. The reason for this honorable distinction is that whey boasts an extremely high concentration of essential amino acids and the highest concentration of branched-chain amino acids (20-25%) of any single protein source. This quality of whey makes it extremely useful in repairing muscle following exercise and promoting its growth. Protein sources with high amounts of branched-chain amino acids, such as whey, are particularly effective in repairing muscle.

Therefore, using whey as part of a post-workout shake will help enhance the benefits of an exercise session, especially if it consists of high-intensity weight training.

Whey Protein and Immunity

Whey protein contains a high concentration of the amino acid cysteine, which occurs in whey linked to another amino acid called glutamic acid. This link forms glutamylcysteine (rare in food protein) and appears to be unbreakable by digestive enzymes. Glutamylcysteine is found in whey as part of the biologically active peptide microfactions, beta-lactoglobulin, serum albumin and lactoferrin.

Once in circulation, cysteine is used to make a very powerful water-soluble intracellular antioxidant called glutathione (GSH) within the human body. As an antioxidant, glutathione serves to protect cells from free radicals species including carcinogens (cancer promoters), peroxides and heavy metals. Glutathione also functions to help keep the antioxidants vitamin C and vitamin E active so they can continue fighting disease-causing free radicals.

Whey protein is considered a very viable cysteine donor since more glutathione production seems to occur when cysteine is delivered linked to glutamic acid than just free cysteine. This important immune boosting characteristic of whey has its potential usefulness in conditions such as AIDS, atherosclerosis, Hepatitis B, Alzheimer’s and cancer being researched. Typically low levels of glutathione are found in those with these diseases. In addition, intense exercise typically generates more free radicals as a result of improperly processed oxygen molecules, and therefore, the antioxidant boosting properties of whey protein would be useful.

Whey protein may also stimulate antibody production since 10% of whey’s protein is composed of immunoglobulin antibodies and is therefore a useful supplement for diseases such as AIDS in which improving the immune system is crucial.

Whey Protein and Fat Loss

A recent animal study showed that whey protein was more effective for weight loss and improving insulin sensitivity compared to the same amount of protein from red meat. Perhaps recent studies showing that dairy products such as milk and yogurt can aid with fat loss has something to do with the whey protein they contain?

Microfiltration and ion exchange are the techniques by which proteins are extracted according to their specific size and electronic charge. Cross-flow ultrafiltration and advanced microfiltration extraction methods can now produce a whey isolate that is 99% pure, leaving less than 1% fat and lactose.

In contrast, whey protein concentrate can range from 30-85% pure protein and thus, contains more non-protein substances such as lactose. As a result of this discrepancy, whey protein isolate is considered superior to whey protein concentrate for muscular repair following exercise since it can work much quicker and contains more pure protein than concentrate. Whey isolate is also less likely to cause adverse gastrointestinal problems such as bloating in response to lactose intolerance.

To purchase the best whey protein powders:

  1. Find a product with mostly whey isolate. To obtain the muscular repair and antioxidant boosting properties of whey, it is important to find a product with more protein isolate than concentrate. This means whey protein isolate must be the first ingredient. A protein powder supplement that says “97% whey protein isolate” on the front label does not necessarily mean the product is 97% isolate – the whey isolate they are using just happens to be 97% pure protein. Isolate may be the third or fourth ingredient in a blend of different proteins.
  2. Ignore proprietary blends. Many companies will come up with a name for their protein blend and then trademark it to make it appear better than the rest. In the ingredient list, you will see this protein blend, and in brackets it will state what makes up this blend. Since ingredients are listed in order of quantity, if concentrate is the first ingredient in the bracket and isolate is the second, then you are getting more concentrate. Companies will use more concentrate because it is much cheaper.
  3. Choose a whey protein that has been processed using low heat. Since cysteine is easily destroyed by excessive heat, low-heat processing will ensure the whey isolate protein can fully donate cysteine to produce the antioxidant glutathione within the body. These protein isolates are also known as un- or non-denaturated. A protein powder with un-denatured whey isolate as the primary protein (first ingredient) is a high-quality supplement. Cold processing will also ensure that the powder maintains its high biological value.
  4. Check serving size. The best whey protein supplements will be mostly protein with very little other stuff (e.g., sugar, fat, preservatives). This is not supposed to be a meal replacement powder, so the calories should not be very high - between 80 and 125 calories is ideal.

To determine protein quantities, take the number of grams of protein per serving and divide this by the total serving size. This needs to be as close to 100% as possible. There are now whey protein powders available that contain only one ingredient: whey protein isolate. This would bring the percentage to approximately 100%.

Whether someone is a bodybuilder, suffering from chronic disease or just concerned about overall health, whey protein isolate should be part of any supplement regimen and included as part of a healthy diet.


  1. Belobrajdic D.P. et al. (2004) A high-whey-protein diet reduces body weight gain and alters insulin sensitivity relative to red meat in wistar rats. J Nutr. Jun;134(6):1454-8.
  2. Belobrajdic D.P. et al. (2003) Whey proteins protect more than red meat against azoxymethane induced ACF in Wistar rats. Cancer Lett. Jul 30;198(1):43-51.
  3. Borsheim E. et al. (2004) Effect of an amino acid, protein, and carbohydrate mixture on net muscle protein balance after resistance exercise. Int J Sport Nutr Exerc Metab. Jun;14(3):255-71.
  4. Bounous G. (2000) Whey protein concentrate (WPC) and glutathione modulation in cancer treatment. Anticancer Res. Nov-Dec;20(6C):4785-92.
  5. Bounous G. et al. (1991) The biological activity of undenatured dietary whey proteins: role of glutathione. Clin Invest Med. Aug;14(4):296-309.
  6. Burke D.G. et al. (2001) The effect of whey protein supplementation with and without creatine monohydrate combined with resistance training on lean tissue mass and muscle strength. Int J Sport Nutr Exerc Metab. Sep;11(3):349-64.
  7. Chromiak J.A. et al. (2004) Effect of a 10-week strength training program and recovery drink on body composition, muscular strength and endurance, and anaerobic power and capacity. Nutrition. May;20(5):420-7.
  8. Ha E. et al. (2003) Functional properties of whey, whey components, and essential amino acids: mechanisms underlying health benefits for active people (review). J Nutr Biochem. May;14(5):251-8.
  9. Lands L.C. et al. (1999) Effect of supplementation with a cysteine donor on muscular performance. J Appl Physiol. Oct;87(4):1381-5.
  10. Low P.P. et al. (2003) Effect of dietary whey protein concentrate on primary and secondary antibody responses in immunized BALB/c mice. Int Immunopharmacol. Mar;3(3):393-401.
  11. Marshall K. (2004) Therapeutic applications of whey protein. Altern Med Rev. Jun;9(2):136-156.
  12. Middleton N. et al. (2004) Whole blood and mononuclear cell glutathione response to dietary whey protein supplementation in sedentary and trained male human subjects. Int J Food Sci Nutr. Mar;55(2):131-41.
  13. Micke P. et al. (2001) Oral supplementation with whey proteins increases plasma glutathione levels of HIV-infected patients. Eur J Clin Invest. 2001 Feb;31(2):171-8.
  14. Watanabe A. et al. (2000) Nutritional therapy of chronic hepatitis by whey protein (non-heated). J Med. 31(5-6):283-302.