Does Whey Protein Promote Yeast Infections?

Whey protein, made from the watery waste of cheese manufacture, contains valuable immunoglobulins, enzymes, proteins and lipids that provide antimicrobial effects against a variety of pathogens. Some components of whey protein inhibit yeast infections. Consult your doctor before using whey protein to treat a yeast infection or other medical condition.


Whey showed antibacterial, antiviral and antifungal activity in a study published in the July 2008 issue of the "Journal of Dairy Science." In the test tube study, free fatty acids in whey inhibited germination of Candida albicans, the fungus responsible for many yeast infections. Whey also inhibited growth of Aspergillus, a type of mold that causes respiratory infections. Active antifungal fatty acids in whey include capric acid, laruoleic acid myristoleic acid and gamma-linolenic acid, also known as GLA. Researchers noted that GLA demonstrated the most potent antifungal effects. Further studies to confirm these preliminary results in humans are needed.


Lactoferrin, an immune-boosting protein abundant in whey protein, helps prevent yeast infections by scavenging iron before it has a chance to become oxidized, according to A.S. Naidu, author of "Lactoferrin: Natural, Multifunctional, Antimicrobial." Pathogenic bacteria and fungi feed on oxidized iron, so limiting its levels has a decidedly antifungal effect. A study published in the July 2011 issue of the "Japanese Journal of Infectious Disease" found that lactoferrin increased effectiveness of the antifungal drug fluconazole. Researchers conclude that lactoferrin shows potential for use in treating drug-resistant fungal strains.

Variable Effectiveness

Swedish researchers found antifungal effects in short protein molecules, known as lactoferrin-like peptides, present in whey protein, in a study published in the January 2011 issue of the "International Journal of Antimicrobial Agents." The peptides inhibited some species of Candida, including Candida albicans, but not others, in the test-tube study. Researchers concluded that antifungal effects of the peptides show potential as antifungal agents in the treatment of most types of Candida. Further studies on the effects of lactoferrin in humans is warranted.

Free Fatty Acids

A study published in the March 2007 issue of the journal "FEMS Yeast Research" found that free fatty acids in whey protein inhibit Candida from reproducing. The fatty acids lauric acid, myrisoleic acid, linoleic acid and arachidonic acid were the most active of those tested in the study. Canadian researchers confirmed the antifungal effects of linoleic acid against Candida albicans in a study published in the April 2011 issue of the journal "Eukaryotic Cell." Researchers concluded that linoleic acid represents an unexplored natural source for controlling Candida infection. Human clinical trials are needed to confirm these promising preliminary results.