Candida, Mold and Yeast Allergies

Candida is often referred to as a pseudoyeast. It's a complex form of fungus with yeast-like traits, rather than an actual yeast, although it's sometimes referred to as "yeast". A regular resident among the many microbes that can be found on the human body, Candida is often benign but under certain circumstances it can cause various infections. Candida may also lead to what is commonly termed a "yeast infection."

It has long been proposed that Candida might also be an allergen. The concept of "candidiasis hypersensitivity" was popularized in the book, The Yeast Connection, originally published in 1983. This condition has also been referred to as the yeast syndrome, yeast allergy, yeast overgrowth or simply "Candida," among other names. However, both the concept of Candida as an allergen and its treatment have remained highly controversial and lack a strong evidence base.

The American Academy of Allergy, Asthma, and Immunology issued a position statement in 1986 that the concept of candidiasis hypersensitivity should be regarded as "speculative and unproven" unless supported by competent research. No additional statements, guidance or approval has been released since that time.

Separate from Candida, yeast and mold allergies are sometimes flagged as items for concern for individuals with conditions such as asthma. While the primary means of allergen transmission is usually by inhaling the allergen for these individuals, consuming them in food form is also of concern. Doing so may cause an allergic reaction for those who test positive for mold and yeast allergies with a potential reported for anaphylaxis, although this is rare.

The management of a yeast and mold allergy requires the elimination of all food that might contain yeast or mold, including:

• Brie, Camembert, Gorgonzola and other blue cheeses that use mold in their ripening process.
• Baked goods leavened with yeast.
• Alcoholic beverages using yeast fermentation as the basis of their production. (Distilled beverages such as spirits, are usually tolerated.)
• Sourdough breads, since its starter is a form of yeast.
• Certain multivitamin preparations and enriched grain products. (Yeast is used as a culture to grow B vitamins and is present in many multivitamin preparations and enriched grain products.)

Registered dietitian nutritionists will likely encounter patients seeking nutrition counseling for suspected or diagnosed food allergies including requests such as a "yeast allergy diet." Seeking out current information and resources to communicate evidence-based recommendations is critical, as is obtaining an accurate diagnosis from an allergist or physician to prevent the unnecessary restriction of foods.

References:

• Joneja JV. Chapter 20: Yeast and Mold Allergy. In: The Health Professionals Guide to Food Allergies and Intolerances. Chicago, IL: Academy of Nutrition and Dietetics; 2012
• Barrett S. Dubious "Yeast Allergies." Quackwatch Revised January 28, 2020. Accessed April 6, 2022
• Candidiasis hypersensitivity syndrome. Executive Committee of the American Academy of Allergy and Immunology. J Allergy Clin Immunol. 1986;78(2):271-273. doi:10.1016/s0091-6749(86)80073-2.
• Collins SC. Practice Paper of the Academy of Nutrition and Dietetics: Role of the Registered Dietitian Nutritionist in the Diagnosis and Management of Food Allergies. J Acad Nutr Diet. 2016;116(10):1621-1631. doi:10.1016/j.jand.2016.07.018.