Nutritional yeast is a species of yeast known as Saccharomyces cerevisiae, which is the same type of yeast used to bake bread and brew beer. It is not a by-product, but rather is typically grown in cane sugar or sugar beet molasses. It has a mild, nutty flavor compared to brewer's yeast. This type of yeast is an excellent source of niacin, folic acid, zinc, thiamine and selenium, and can be fortified with vitamin B-12, an important nutrient for vegans who are more susceptible to B-12 deficiency.
Nutritional yeast also contains a large amount of antioxidants, such as glutathione and selenomethionine, which can help reduce oxidative stress in the body, reduce inflammation, and help eliminate heavy metals and toxins. In recent years, many people have started to consume nutritional yeast as a dietary supplement. It is produced by adding synthetic nutrients to a substrate and then undergoing a heating and drying process that renders it inactive. Fortunately, the amount of lead in any brand of nutritional yeast was not at a level that was a cause for major concern.
While some people believe that nutritional yeast improves glucose sensitivity in people with type 2 diabetes, studies have not yet demonstrated this. People with yeast sensitivity or allergy should also take care to avoid any exposure to nutritional yeast. Some brands of nutritional yeast may contain more than one standard serving of folic acid, so people should consult a doctor before using it as a supplement. In addition, some researchers say that people with a higher risk of gout may want to avoid nutritional yeast.
While both brewer's yeast and nutritional yeast naturally contain reasonable amounts of magnesium, in general, brewer's yeast has a much higher concentration of many minerals.