Can you get sick from eating yeast?

In this short article, we will provide an answer to the question, “Can you get sick from eating yeast?” with an in-depth analysis of different types of yeast, possible side effects of eating yeast, yeast allergies and their symptoms.

Can you get sick from eating yeast?

The answer is yes, you can get sick from eating yeast. Yeast is effectively used in the production of wine and beer. Additionally, we use yeast for baking bread and other bakery products. So, it depends upon the type of yeast you are consuming. However, the real concern is that certain individuals may be allergic to yeast. 

Types of yeasts

  • Nutritional yeast: 

Nutritional yeast is available in many forms, such as powders, liquids, and flakes. It has a cheesy taste and adds beneficial nutrients to your diet including vitamin B-complex and selenium. In contrast to brewer’s yeast, it is often supplemented with vitamin B12, making it especially beneficial to vegans.

  • Brewer’s yeast: 

Brewer’s yeast is a well-known yeast used in the production of wine and beer. In addition, it is also used as a nutritional supplement for various health problems such as it helps to improve gastrointestinal symptoms in patients with irritable bowel syndrome, and also helps in lowering blood glucose in diabetic patients. 

Brewer’s yeast is made from a strain of the fungus Saccharomyces cerevisiae. It is a rich source of B vitamins, that aids in the conversion of fats, proteins and carbohydrates to energy, and also contains chromium and selenium that helps in controlling blood sugar levels and production of thyroid hormone, respectively. 

  • Baker’s yeast:

As the name indicates, baker’s yeast is used in baking bread and other bakery products. This can be found in different forms including liquid, active dry, fresh, and instant. 

Baker’s yeast is the principal leavening agent used in the process of baking. It is also made from Saccharomyces cerevisiae, but with a different strain. It is not rich in nutrients, hence is not used as a dietary supplement. 

Side effects of consuming different types of yeasts 

If a certain type of yeast is consumed in excess it can lead to various health problems. Below we will discuss possible side effects of consuming nutritional and active dry yeast in abundance. 

Nutritional yeasts

  • May trigger headaches or migraines: Though nutritional yeast is a rich source of minerals and vitamins, some yeast products consist of tyramine compounds, that can lead to headaches and migraines in some people.
  • May Cause Facial Flushing: Nutritional yeast is a rich source of niacin (commonly known as vitamin B3) which is involved in various body mechanisms. 

Nevertheless, excessive niacin consumption may cause facial flushing, which may lead to a burning and itching feeling within 10–20 minutes of consumption. However, it is usually harmless and goes away within one to two hours. 

But, facial flushing normally happens only after consuming niacin in higher amounts, such as 500 milligrams or higher, which can usually only be achieved through supplements. 

  • May cause digestive problems if introduced too promptly: Nutritional yeast is high in fibres. For this reason, if it is introduced too quickly it can trigger abdominal discomfort, especially if you are not used to a high fibre diet. 

Active dry yeast

Active dry yeast is the manufactured form of yeast. These are dried granules of yeast that consume sugars during the cooking process. 

If active dry yeast is consumed directly, it can survive in the stomach due to the granular structure of the yeast. In the stomach, it can break down sugars, causing a rise in gas or alcohol. 

Additionally, if this yeast is consumed with bread dough, the yeast would create more waste products in the stomach, causing an increase in stomach pain.

Brewer’s yeast

Excessive alcohol consumption can lead to the overgrowth of yeast in the stomach. The hydrochloric acid in your stomach may not be able to neutralize it which in turn can cause stomach problems. 

To sum up, you should never consume live active yeast in any form or dry active yeast that can activate on contact with food in your stomach. However, baked products that have killed the yeast inside the dough or nutritional yeast that has been baked to kill the yeast is safe to consume. 

Yeasts allergies

Many people are allergic to yeast present in different foods. Symptoms associated with yeast allergies range from mild to severe. These include

  • Stomach distress
  • Diarrhoea
  • Bloating and gas
  • Dizziness
  • Skin rash or irritation
  • Joint pain

Chances of a severe reaction i.e., anaphylaxis from yeasts allergies are rare. This can cause trouble breathing, a swollen throat, and low blood pressure.

Yeast multiply by the means of tiny spores that can travel through the air. People who are allergic to yeasts may develop respiratory problems after inhaling the spores.

Symptoms may include:

  • breathing problems
  • Congestion
  • hives

Sources of a yeast allergy may include:

  • Bread and bakery products such as biscuits, muffins, cinnamon rolls or croissants
  • Ciders, wine and beer
  • Vinegar and Soy sauce
  • Mushrooms and olives
  • Yoghurt, synthetic cream, and buttermilk
  • fermented foods including sauerkraut and ripe cheeses 
  • Berries and grapes
  • Dried fruits and cereals
  • Anything that has been opened and kept for an extended period of time


In this brief guide, we have provided an answer to the query, “Can you get sick from eating yeast?”. Moreover, we have discussed different types of yeast, possible side effects of eating yeast, yeast allergies and their symptoms.


Hi, I am Charlotte, I love cooking and in my previous life, I was a chef. I bring some of my experience to the recipes on this hub and answer your food questions.