Whey protein is a mixture of some of the proteins naturally found in milk. The major proteins found in whey protein include beta-lactoglobulin and alpha-lactalbumin. Whey protein has one of the highest protein digestibility-corrected amino acid scores (PDCAAS; a measure of protein bioavailability) and is more rapidly digested than other proteins, such as casein (another milk protein). 1
During the process of making milk into cheese, whey protein is separated from the milk. This whey protein is then incorporated into ice cream, bread, canned soup, infant formulas, and other food products. Supplements containing whey protein are also available.
Some athletes say that whey protein
Protein is necessary for rebuilding tissue—this is especially important for bodybuilders. All types of protein provide the body with amino acids. From an athletic point of view, whey is just another type of protein. Choosing whey protein over other types of protein simply adds variety to the protein choices available.
Whey is a common ingredient in many meal replacements, which are designed to provide a large amount of nutrients in a minimal amount of calories.
Animal studies suggest that whey protein can increase gains in lean body mass resulting from exercise.2 A controlled trial found that six weeks of strength training while taking 1.2 grams of whey protein per 2.2 of pounds body weight per day resulted in greater gains in lean body mass, but improved only one out of four strength tests.3 Another controlled study found that people taking 20 grams per day of whey protein for three months performed better on a test of short-term intense cycling exercise than people taking a similar amount of milk protein (casein).4 However, a double-blind trial found that men taking 1.5 grams per 2.2 lbs of body weight per day of predigested whey protein for 12 weeks along with a strength-training exercise program gained only half as much lean body mass and had significantly smaller increases in strength compared with men using a similar amount of predigested casein along with strength training.5 A controlled study of HIV-infected women found that adding whey protein to strength-training exercise was no more effective than exercise alone for increasing strength or improving body composition.6
People who are allergic to dairy products could react to whey protein and should, therefore, avoid it.7 As with protein in general, long-term, excessive intake may be associated with deteriorating kidney function and possibly osteoporosis. However, neither kidney nor bone problems have been directly associated with consumption of whey protein, and the other dietary sources of protein typically contribute more protein to the diet than does whey protein. The possibility that certain proteins in milk may contribute to the development of diabetes in children is controversial. But since whey proteins include some of the same milk proteins, people who are avoiding milk because of concerns about the risk of diabetes should not consume whey protein either.
At the time of writing, there were no well-known drug interactions with whey protein.
See a list of books, periodicals, and other resources for this and related topics.
*Athletes and fitness advocates may claim benefits for whey protein based on their personal or professional experience. These are individual opinions and testimonials that may or may not be supported by controlled clinical studies or published scientific articles on whey protein. For more complete and detailed information, including references and safety information, see Whey Protein as a nutritional supplement.
1. Dangin M, Boirie Y, Guillet C, Beaufrere B. Influence of the protein digestion rate on protein turnover in young and elderly subjects. J Nutr 2002;132:3228S–33S [review].
2. Bouthegourd JC, Roseau SM, Makarios-Lahham L, et al. A preexercise alpha-lactalbumin-enriched whey protein meal preserves lipid oxidation and decreases adiposity in rats. Am J Physiol Endocrinol Metab 2002;283:E565–72.
3. Burke DG, Chilibeck PD, Davidson KS, et al. 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 2001;11:349–64.
4. Lands LC, Grey VL, Smountas AA. Effect of supplementation with a cysteine donor on muscular performance. J Appl Physiol 1999;87:1381–5.
5. Demling RH, DeSanti L. Effect of a hypocaloric diet, increased protein intake and resistance training on lean mass gains and fat mass loss in overweight police officers. Ann Nutr Metab 2000;44:21–9.
6. Agin D, Gallagher D, Wang J, et al. Effects of whey protein and resistance exercise on body cell mass, muscle strength, and quality of life in women with HIV. AIDS 2001;15:2431–40.
7. Wal JM. Cow's milk proteins/allergens. Ann Allergy Asthma Immunol 2002;89(6 Suppl 1):3–10.
Copyright © 2007 Healthnotes, Inc. All rights reserved. www.healthnotes.com
The information presented in Healthnotes is for informational purposes only. It is based on scientific studies (human, animal, or in vitro), clinical experience, or traditional usage as cited in each article. The results reported may not necessarily occur in all individuals. For many of the conditions discussed, treatment with prescription or over the counter medication is also available. Consult your doctor, practitioner, and/or pharmacist for any health problem and before using any supplements or before making any changes in prescribed medications. Information expires September 2008.