Whey Protein

Also indexed as: Protein (Whey)

What is it?

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

Alpha-lactalbumin is a whey protein high in the amino acid tryptophan, which the body uses to make the neurotransmitter serotonin. A double-blind study found that supplementing the diet with alpha-lactalbumin helped improve scores on a memory test in people who were vulnerable to experiencing problems with stress.2 The researchers speculated that the alpha-lactalbumin raised brain serotonin levels in these subjects, which may have improved their tolerance to stress.

Where is it found?

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.

Whey protein has been used in connection with the following conditions (refer to the individual health concern for complete information):

Rating Health Concerns
2Stars

Athletic performance
1Star

Cancer

Hepatitis

HIV infection

Immune function

Osteoporosis

Stress

Weight loss and obesity
3Stars Reliable and relatively consistent scientific data showing a substantial health benefit.
2Stars Contradictory, insufficient, or preliminary studies suggesting a health benefit or minimal health benefit.
1Star For an herb, supported by traditional use but minimal or no scientific evidence. For a supplement, little scientific support and/or minimal health benefit.

Who is likely to be deficient?

People who do not include dairy foods in their diets do not consume whey protein. However, the amino acids in whey protein are available from other sources, and a deficiency of these amino acids is unlikely.

People who do not include dairy foods in their diets do not consume whey protein. However, the amino acids in whey protein are available from other sources, and a deficiency of these amino acids is unlikely. In fact, most Americans consume too much, rather than too little, protein.

How much is usually taken?

Some benefits of whey protein have been demonstrated with as little as 20 grams per day. For athletes in training a commonly used amount is 25 grams of whey protein per day, and shouldn’t exceed 1.2 grams per 2.2 pounds body weight. Most clinical research has used similar amounts of whey protein.

Are there any side effects or interactions?

People who are allergic to dairy products could react to whey protein and should, therefore, avoid it.3 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.

People who are allergic to dairy products could react to whey protein and should, therefore, avoid it. 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 whey protein, and the other dietary sources of protein typically contribute more protein to the diet than does whey protein.

At the time of writing, there were no well-known drug interactions with whey protein.

References

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. Markus CR, Olivier B, de Haan EH. Whey protein rich in alpha-lactalbumin increases the ratio of plasma tryptophan to the sum of the other large neutral amino acids and improves cognitive performance in stress-vulnerable subjects. Am J Clin Nutr 2002;75:1051–6.

3. Wal JM. Cow's milk proteins/allergens. Ann Allergy Asthma Immunol 2002;89(6 Suppl 1):3–10.