Benefits and Side Effects of Brewer's Yeast

If the term "brewer's yeast" makes you think of beer, you're on the right track. Brewer's yeast, which is more officially known as Saccharomyces cerevisiae, is an actual yeast that's used in both baking and the fermentation of beer. It's also collected after beer-making and sold as a supplement.

Natural brewer's yeast is rich in protein and various nutrients that give it a lot of health benefits, like helping to balance your blood sugar levels. But the yeast also has the potential to cause some side effects, like gas and migraines. Brewer's yeast can also interfere with certain medications, so always talk to your doctor before taking it — or any other supplement.

You may already know that your gut is home to trillions of bacteria, but did you know that other microorganisms, like yeast, naturally live there too? Most of the bacteria and yeast stay confined within the walls of your digestive tract, but there are times when these microorganisms can either become overgrown in other areas or start to get out of balance in your gut. That's where things like brewer's yeast come in.

Kaiser Permanente defines brewer's yeast as the dried, pulverized cells of Saccharomyces cerevisiae, which is a type of fungus (or yeast). Brewer's yeast is typically formed as a byproduct of beer-making, but it can also also be grown exclusively for use as a nutritional supplement. However, the two have different nutritional profiles.

Although they're all microorganisms, brewer's yeast is different from other types of yeast, like nutritional yeast, baker's yeast (which is often used in baked goods and breads) or torula yeast.

Brewer's yeast is classified as a probiotic, which means it can help contribute to the proper balance of yeast and bacteria in your gut and maintain good gut health. It's also rich in several nutrients. One of the most notable is chromium, but it also contains:

• B vitamins
  
• Selenium
  
• Potassium
  
• Iron
  
• Zinc
  
• Magnesium
  
• Protein (about 52 percent by weight)

Brewer's yeast also contains something called beta-glucans, which are special types of sugars found in the cell walls of yeast, as well as bacteria, fungi and other plants. In a 2017 report published by the National Institute of Hygiene in Poland, researchers identified a certain beta-glucan, called zymosan, as responsible for some additional health benefits.

According to the report, zymosan has antibacterial properties that can help boost your immune system. Zymosan also acts as an antioxidant and stimulates your body to release tumor necrosis factor and cytokines, other substances that play a role in fighting off chronic diseases.

Read more: Is Eating Yeast Bad for You?

Because it's rich in chromium, researchers also thought brewer's yeast could possibly help with blood sugar problems — and they were right. In a small study that involved 84 adults with Type 2 diabetes that was published in the International Journal of Preventive Medicine in October 2013, researchers divided the group into two smaller groups.

One of the smaller groups received 1,800 milligrams of brewer's yeast per day for 12 weeks, while the other group received a placebo. Each person's fasting blood sugar, hemoglobin, insulin sensitivity and insulin resistance were measured before and after the study.

Researchers found that after the 12 weeks, fasting blood sugar, hemoglobin and insulin sensitivity were significantly different between the two groups. The group that was taking the brewer's yeast experienced a drop of 12.4 grams per deciliter in their fasting blood sugar, while the placebo group had increases in blood sugar.

Hemoglobin decreased by 1.1 percent in the brewer's yeast group and rose slightly (by 0.1 percent) in the placebo group. The brewer's yeast group also had increased insulin sensitivity.

It's also a possibility that brewer's yeast can interact with some medications you're taking. The most common interaction is with a class of drugs called monoamine oxidase inhibitors (or MAOIs), which are often used as part of the treatment plan for depression. Brewer's yeast contains an amino acid called tyramine, which helps regulate blood pressure. MAOIs block monoamine oxidase, an enzyme that breaks down excess tyramine.

If you're taking an MAOI and you get a lot of tyramine, the amino acid can accumulate to dangerous levels and cause a spike in your blood pressure that may require emergency treatment.

Brewer's yeast can also cause an increase in gas production and may trigger migraines, especially in those who are already prone to getting them. If you have gout or Crohn's disease, you shouldn't take brewer's yeast. Even if you don't have an existing health condition and aren't taking medications, you should talk to your doctor before taking it.

Although having a true yeast allergy is extremely rare, according to a case study involving a 19-year-old man published online in March 2017 in the journal Case Reports in Immunology, it is possible, so it's worth a mention. If you do have a yeast allergy, you'll experience symptoms shortly after taking a brewer's yeast supplement or drinking a beverage, like beer, that's been fermented with the yeast.

Some possible symptoms of a yeast allergy include:

• Wheezing
  
• Hives
  
• Itchy skin
  
• Itchy mouth and throat
  
• Nasal blockage
• Swelling/constriction of the throat

If you experience any of these symptoms after consuming brewer's yeast, seek emergency medical attention first, and then you'll have to indefinitely avoid brewer's yeast and any food or drink made with the yeast.

Read more: Foods to Avoid with a Yeast Intolerance

Brewer's yeast is available over-the-counter as a supplement in powder, capsule or tablet form. Kaiser Permanente notes that, typically, doctors will recommend taking 1 to 2 tablespoons (or 15 to 30 grams) of brewer's yeast per day. If you're taking it in powdered form, you can mix it right into your food, glass of juice or water. If you're taking a capsule or tablet, you can simply swallow it with some water.

Natural brewer's yeast that's formed as a byproduct of beer-making has a bitter taste. If the brewer's yeast you're taking doesn't have that bitter taste, it's likely that it's not real and doesn't contain significant amounts of chromium, which is responsible for some of its major health benefits.

Of course, the exact amount of brewer's yeast that's right for you will depend on your health status and your reasons for taking it, so check with your doctor before deciding on your dose.