In the late 1970s and 1980s, a pair of doctors in the United States promoted the idea that an allergy to a common yeast type of fungus, Candida albicans, was behind a host of symptoms. They pinned a long list of symptoms on Candida, including:

  • abdominal bloating, constipation, and diarrhea
  • anxiety and depression
  • hives and psoriasis
  • impotence and infertility
  • menstrual problems
  • respiratory and ear problems
  • unexpected weight gain
  • feeling “bad all over"

According to doctors C. Orian Truss and William G. Crook, it was difficult to find any symptom that couldn't be traced back to Candida albicans. They suggested that 1 out of 3 Americans suffered from a yeast allergy, and also coined “candida-related complex.” An entire supplement industry sprung up around “the yeast problem.”

However, the real problem wasn't yeast — it was that the science behind the allergy turned out to be mostly bogus. State and medical boards began fining the doctors involved in promoting and treating Candida allergy, and they put these doctors’ licenses on probation for this as well.

Does that mean yeast allergies don't exist? No, they do — they're just not nearly as common as these doctors proposed.

According to the American College of Allergy, Asthma, and Immunology, over 50 million Americans have some type of allergy. Only a small portion of allergies are food allergies, and yeast allergy makes up only a tiny fraction of food allergies.

Sources of a yeast allergy may include:

  • most breads and some baked goods, such as muffins, biscuits, croissants, or cinnamon rolls
  • cereal products
  • alcohol, especially beer, wine, and ciders
  • premade stocks, stock cubes, and gravies
  • vinegar and foods containing vinegar, such as pickles or salad dressing
  • aged meats and olives
  • mushrooms
  • fermented foods such as ripe cheeses and sauerkraut
  • dried fruits
  • blackberries, grapes, strawberries, and blueberries
  • buttermilk, synthetic cream, and yogurt
  • soy sauce, miso, and tamarind
  • tofu
  • citric acid
  • anything that has been opened and stored for an extended period of time

When someone is having a negative reaction to yeast, they need to determine whether they have a yeast buildup, a yeast intolerance, or a yeast allergy.

Yeast buildup

In some cases, having an abundance of yeast in the body can result in a fungal infection. This will cause many of the same symptoms as an allergy, with the difference being that the infection can be cured.

Yeast intolerance

A yeast intolerance generally has less severe symptoms than a yeast allergy, with symptoms largely limited to gastrointestinal symptoms.

Yeast allergy

A yeast allergy can affect the entire body, leading to skin reactions, changes in mood, and widespread body pain. Allergic reactions can be dangerous, and can cause long-term damage to the body. In a true allergy, your immune system is responding to a foreign substance that is not typically harmful to your body.

Symptoms of a yeast allergy can vary from person to person, but they may include one or more of the following:

  • abdominal swelling
  • breathing difficulties
  • dizziness
  • joint pain

There is a common misconception that a yeast allergy is the cause of the red, blotchy skin that some people develop after drinking alcoholic beverages. This rash is usually an allergy-like reaction (not a true allergy) related to sulfur dioxide in alcoholic drinks. Sulfur dioxide may activate allergy-like reactions to other substances it is found within, such as wheat-containing foods where this and other sulfites are used as preservatives. Sometimes histamine release and tannins will trigger rashes as well. A yeast allergy will typically not cause a rash.

Anyone can develop a yeast allergy, but certain individuals are more likely to than others.

One of the most common risk factors for developing a yeast overgrowth or allergy is a weakened immune system. People with diabetes mellitus are also at a higher risk.

People with a family history of a yeast allergy are at increased risk. And if you have a food allergy, there is an increased likelihood that you’re also allergic to something else.

There are several tests available to confirm allergies to yeast or to other foods. These include:

  • Skin prick test: A small drop of the suspected allergen is placed on the skin and pushed through the first layer of skin with a small needle.
  • Intradermal skin test: A syringe is used to inject the suspected allergen into the tissue beneath the skin (also called the dermis).
  • Blood or RAST test: This test measures the amount of the immunoglobin E (IgE) antibody in the blood. A high level of IgE specific to an allergen source is likely indicative of an allergy.
  • Food challenge test: A person is given increasing amounts of a suspected allergen as a clinician watches for a reaction. This is considered a definitive test for most food allergies.
  • Elimination diet: An individual stops eating the suspected allergen for a period of time and then slowly introduces it back into the diet while recording any symptoms.

Gluten sensitive enteropathy (also known as celiac disease and celiac sprue) may be confused with yeast allergies. Gluten intolerance due to celiac sprue is an autoimmune disease, as opposed to an allergy. Gluten is a mixture of proteins, found in grains such as wheat, rye, and barley. It’s often added to processed foods.

To test for celiac disease, your doctor may take a biopsy of your small intestine. Flattened villi (the small finger-like tubes that line the wall of the small intestine) are a definitive sign of celiac disease. Additionally, the bloodstream of people who have this autoimmune disease will show presence of anti-TTG autoantibodies (mainly IgA and sometimes also IgG) as well as deamidated gliadin autoantibody. Totally removing gluten from the diet for life is how you improve the symptoms of gluten sensitive enteropathy.

If an individual continues to consume yeast when he or she is allergic to it, it can be associated with an array of symptoms and problems, such as difficulty concentrating, mood disorders, ear infections, and more. Long-term effects and damage may also occur.

Yeast allergies or overgrowth may be related to a weakened immune system or diabetes mellitus. These underlying causes will need to be treated on their own.

Items that you can eat or drink freely include:

  • soda breads, which are typically yeast-free
  • fruit smoothies
  • protein, such as unprocessed meat and fish
  • skim milk
  • green vegetables
  • beans
  • potatoes
  • squash
  • grains, such as brown rice, corn, barley, and rye
  • oats

However, you should always check the label.

Yeast allergies are not very common and there isn’t a lot of scientific research behind them. However, some people do experience reactions. Talk to your doctor if you think you may have a yeast allergy. Your doctor can refer you to an allergist who can properly diagnose and confirm the allergy. The main treatment for any food allergy is to avoid the food causing the reaction. Your doctor and allergist can help you find healthy ways to remove yeast from your diet.