Nutritional yeast is similar to that used in baking or brewing (Saccharomyces cerevisiae), except that it has been deactivated. It is popular in vegan cooking due to its Parmesan cheese-like flavor. But its overall savory taste, which many have described as umami (the “fifth taste”), goes beyond cheesy, making it a versatile culinary seasoning for dishes of all types.^1,2 Nutritional yeast isn’t just a tasty seasoning though. Available in powder, flakes, or granules, nutritional yeast provides all nine essential amino acids, making it a complete protein. Two tablespoons provide eight grams of protein and four grams of fiber. It is considered a low-glycemic food and also provides several trace minerals, including chromium, iron, selenium, manganese, and molybdenum.² Fortified nutritional yeast, in particular, is an excellent source of the B vitamins (B2, B3, B6, B9, and B12), making it a healthy addition to a vegan diet, in which vitamin B12 is especially lacking.² Nutritional yeast has many other potential health benefits.

Potential Benefits

Heart health. Nutritional yeast contains beta-glucan, a form of soluble fiber that has been shown to help reduce risk factors associated with heart disease, including high cholesterol, obesity, high blood pressure, atherosclerosis, and oxidative stress.⁴ Diabetes is another risk factor associated with heart disease, and fortified nutritional yeast and brewer’s yeast contain chromium, a mineral that, like beta-glucan, plays an essential role in regulating blood sugar levels and insulin metabolism.⁵ The glutathione in nutritional yeast is a powerful antioxidant that also supports a healthy heart. Glutathione is a polypeptide that protects cells against free radicals and pro-oxidants and maintains oxidant-antioxidant homeostasis within the cells.⁶ 

Immune system functioning. Nutritional yeast contains selenomethionine, a naturally occurring form of the mineral selenium. Selenomethionine combines with proteins in the body to form the antioxidant selenoprotein, which plays a critical role in regulating immune cell functioning.⁷ The beta-glucan in nutritional yeast also plays an important role in immune system functioning.⁸ Beta-glucan acts as an effective immunomodulator and enhances the anti-tumoral activity of macrophages in the lining of the abdominal cavity.⁸ Beta-glucan has also been shown to elicit broad antimicrobial effects against Staphylococcus aureus, Escherichia coli, Candida albicans, Pneumocystis carinii, Listeria monocytogenes, Leishmania donovani, and influenza virus.⁸

Physical recovery. The beta-glucan in nutritional yeast has been shown to have a positive effect on muscle tissue recovery, fatigue recovery time, and endurance in athletes. Researchers believe that beta-glucan promotes the aerobic capacity of the body, but how this is achieved is unclear. It has been suggested that beta-glucan’s regulating effects on blood urea nitrogen, lactic acid, and creatine may be involved.⁹ One study found that athletes who consumed 250mg/day of beta-glucan derived from baker’s yeast had greater concentrations of plasma immune response markers and shorter recovery periods following strenuous activity compared to the athletes who consumed the placebo.¹⁰ Nutritional yeast also contains zinc, a trace mineral involved in the body’s response to oxidative stress, homeostasis, immune system functioning, deoxyribonucleic acid (DNA) replication, DNA damage repair, and cell cycle progression. Zinc also helps in muscle repair and regeneration due to its role in the synthesis of protein and collagen.¹¹  

Fighting fatigue. Fortified nutritional yeast is an excellent source of vitamins B2, B3, B6, B9, and B12. In fact, two teaspoons of fortified nutritional yeast provides 246 percent of the daily value (DV) for riboflavin (B2), 109 percent DV for niacin (B3), 212 percent DV for pyridoxine (B6), 59 percent DV for folate (B9), and a whopping 313 percent DV for cobalamin (B12).² Vitamin B12, along with the other B vitamins, is required for the creation of cellular energy from dietary fats and proteins. B12 is also involved in the production of hemoglobin, and a deficiency in B12 can lead to hemoglobin-deficient anemia. Those who are deficient in the B vitamins, especially B12, may experience symptoms of chronic fatigue and weakness.¹² Nutritional yeast is a tasty way to ensure you’re getting enough of the B vitamins in your diet. 

Potential Risks

While nutritional yeast is generally considered safe for most people, side effects may occur in sensitive individuals, those on certain medications, and those with certain medical conditions. The warnings below are for baker’s, brewer’s, and nutritional yeast products.

Dietary yeast contains tyramine, an amino acid that plays a role in blood pressure regulation.¹³ Tyramine may trigger headaches or migraines in susceptible individuals. Tyramine can also interact negatively with certain medications, such as monoamine oxidase inhibitors.¹³ Individuals who are susceptible to headaches or migraines and people on monoamine oxidase inhibitors should consult with their physicians before consuming yeast. 

People with yeast or mold allergies should not consume yeast. Additionally, research has shown an association between atopic dermatitis and yeast sensitivity; thus, individuals with atopic dermatitis should not consume yeast.^14–18

Dietary yeast products are at risk of being contaminated with ochratoxin A, a mycotoxin that can harm the kidneys. While this has only been reported in brewer’s yeast samples, it is important to choose lab-tested dietary yeast products from trusted manufacturers.^14,19,20

Dietary yeast products are high in uric acid and its precursor purine. Therefore, individuals with kidney stones or gout should not consume dietary yeast products.^14,21,22

People with celiac disease or Crohn’s disease may have antibodies to S. cerevisiae, the fungus used to make yeast. Therefore, consuming yeast products may aggravate disease symptoms. Consult with a physician before consuming yeast.^14,23,24

Nutritional yeast provides about 20 percent DV of fiber, which may cause gastrointestinal discomfort in individuals who are not used to consuming a lot of fiber. For these people, starting with a smaller portion and drinking lots of water may help.² 

Editor’s note. Fortified and unfortified nutritional yeast products can vary in a number of ways, from manufacturing process, to the amount and type of nutrients added, to the type of fungus from which the yeast was derived (though most come from S. cerevisiae). Thus, it is important to read the labels carefully to find the nutritional yeast product best for you. Consult with your physician before incorporating nutritional yeast into your diet..

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