By Dr. Mercola
Nutritional yeast, commonly known as nooch, is popular among people following a vegetarian or vegan diet. It provides a non-animal source of protein that contains all nine essential amino acids (the ones you can obtain only via your diet, typically from animal protein sources).
Nutritional yeast is also widely regarded as a good source of B vitamins, including vitamin B12, another nutrient typically only found in animal foods. Perhaps best of all, nutritional yeast has a nutty, cheese-like flavor that can be used as a cheese substitute in recipes.
This food, which is neither plant nor animal but rather fungus, like mushrooms, can certainly be an incredible dietary addition. In fact, I eat it frequently myself. But you have to be careful when using nutritional yeast, as misconceptions abound, especially in its relation to brewer's yeast.
To be sure you're getting the most out of this healthy fungus, here are some essential facts you should know.
Nutritional Yeast and Brewer's Yeast Come From the Same Yeast
Both nutritional yeast and brewer's yeast are a type of yeast called Saccharomyces cerevisiae (S. cerevisiae). S. cerevisiae has many uses. It can be used to make bread, beer or kombucha tea, for instance. In those cases, the yeast is alive, i.e., "active."
The yeast you purchase in supplemental dried flake form, on the other hand, is inactivated. This means you cannot use it to make beer or bread, but you also don't have to worry that consuming it could lead to yeast overgrowth or infection in your body.
Traditionally, brewer's yeast was a byproduct of the beer-making process (hence its name). Its nutritional contents were more of an afterthought, not its primary purpose, and it had to have its bitter flavor removed in order to be palatable as a nutritional supplement.
Brewer's yeast was traditionally rich in chromium, an essential mineral that plays a role in insulin use and blood sugar regulation. However, since today brewer's yeast is grown on a variety of mediums and isn't typically a brewery byproduct, this assumption can no longer be made.
Likewise, nutritional yeast is often regarded as a rich source of vitamin B12, and many vegans rely on it for this purpose. However, not all nutritional yeasts contain vitamin B12 (though most do). In order to know for sure, reading the label is essential.
How Are Nutritional Yeast and Brewer's Yeast Grown?
Nutritional yeast is typically grown on sugar beets (which are often genetically engineered (GE)), sugar beet molasses or sugar cane molasses. Because of this it's often assumed to be gluten-free.
However, if you are following a gluten-free diet, you must confirm with the manufacturer whether or not the yeast is truly gluten-free because some yeast, especially brewer's yeast, is grown on grains.
Brewer's yeast may be grown on the same plant derivatives as nutritional yeast, but sometimes it's also grown on barley or malt to mimic the brewery process.
Regardless of the source, most brewer's yeast and nutritional yeast are referred to as "primary grown," meaning they are grown specifically for use as a supplement.
As mentioned, it's also important to confirm whether B12 is added to nutritional yeast. It often is fortified with B12 (along with zinc, selenium and other B vitamins), but you'll need to read the label to be sure. Brewer's yeast is not a rich source of vitamin B12.
The Homeschooling Doctor shared some additional insights into the differences between the two yeasts:1
- It can refer to live S. cerevisiae to be used for brewing.
- It can be spent brewer's yeast (S. cerevisiae) that is deactivated and ground for supplements.
- It can refer to primary grown S. cerevisiae that is called brewer's yeast.
Nutritional yeast: S. cerevisiae that is grown primarily for supplemental use (so it has been inactivated and ground up), mostly on sugar beet or sugar cane products (molasses). Usually this name implies that vitamin B 12 was added."
Why Is Nutritional Yeast Good For You?
Nutritional yeast is a unique and rich source of many nutrients, including B vitamins, amino acids, at least 14 minerals and 17 vitamins (not including vitamins A, C and E). It also contains phosphorus, chromium and more.
As noted, it is a myth that it naturally contains B12, but this vitamin is often added in. Nutritional yeast also contains beta-1,3 glucan, trehalose, mannan and glutathione, which support healthy immune function.2
According to yeast expert Seymour Pomper, Ph.D., not only is nutritional yeast safe to eat, but it's also the fourth most prescribed herbal monopreparation in Germany because of its anti-viral and antibacterial properties. It may be useful for the following indications:3
- Candida infection
- Chronic acne
- Loss of appetite
- Immune system stimulation
Nutritional Yeast Is Excellent for Athletes
Nutritional yeast has long been regarded as an energy-boosting food. In 2013, research published in the British Journal of Nutrition confirmed this and also found it may boost post-exercise immunity.4 Athletes who ate three-quarters of a teaspoon of a type of fiber found in nutritional yeast per day ended up having higher amounts of circulating monocytes two hours after intense exercise—higher, in fact, than their pre-workout numbers.
To assess whether this actually translated into fewer illnesses, researchers tested the nutritional-yeast fiber on marathon runners. Compared to placebo, the runners who ate the fiber cut in half the number of days they were sick over the following two plus weeks after the race. As reported by Dr. Michael Greger:5
"Those runners who were taking the equivalent of a daily spoonful of nutritional yeast cut their rates of infection in half. And they felt better, too. They were asked how they felt on a scale of one to ten. People taking the sugar pills were okay, down around four or five, but those taking identical looking capsules of the fiber found in nutritional yeast were up at six or seven."
A High-Quality, Easily Digested Protein
Nutritional yeast is also a high-quality source of protein (71 percent by weight) that is easily digested. As explained by Kimberly Snyder, C.N., "Yeast is a single celled microorganism that feeds off sugar." She continued:6
"It needs the same vitamins and amino acids that we humans do, yet because nutritional yeast is grown on sugary foods lacking in some nutrients, the yeast is forced to manufacture its own amino acids and vitamins through biochemical reactions.
… Nutritional yeast is unique in that it is truly a protein-rich food, low in fat and carbohydrates, and very easily digested.
While I'm not a believer in loading up on massive amounts of protein and I think most people get too much, getting another 5-10 grams per day through nutritional yeast can be excellent — especially if you're active or trying to build strength or muscle."
Nutritional Yeast Myth: Too Much Phosphorus
Because nutritional yeast is high in phosphorus, it's sometimes warned that it may deplete your body of calcium (and some yeast manufacturers add calcium for this reason).
While it's true that too much phosphorus can lead to imbalance in your body's pH that then depletes your body of calcium, there's not that much phosphorus in nutritional yeast to make this a concern. (You're probably more likely to experience this from drinking soda, which contains phosphoric acid.)
If, however, you consume a lot of nutritional yeast on a daily basis, you can compensate for its high phosphorus levels by consuming it along with naturally calcium-rich foods, like kale.
Does Nutritional Yeast Contain MSG-Like Compounds?
It's sometimes said that nutritional yeast contains compounds similar to monosodium glutamate (MSG), an excitotoxin that overexcites your cells to the point of damage or death, causing brain damage. MSG is approximately 78 percent free glutamic acid, the same neurotransmitter that your brain, nervous system, eyes, pancreas, and other organs use to initiate certain processes in your body.
Yeast is a natural source of umami flavor, or natural glutamic acid (glutamate). This is what gives it its rich, satisfying, almost meat-like flavor. It's also what triggers the MSG fears, but they are unfounded.
The glutamic acid found in nutritional yeast is "bound" to other amino acids or proteins. The glutamic acid that is MSG is not. When you eat glutamic acid in real foods, your body controls how much is absorbed. Excess glutamic acid is passed off as waste, not stored in your body. As reported by Smithsonian magazine:7
"Glutamates that occur naturally in food come intertwined with different chemicals or fiber, which the body is naturally inclined to regulate, explains Amy Cheng Vollmer, professor of biology at Swarthmore College. MSG, however, comes without the natural components of food that help the body regulate glutamic levels … 'The bottom line here is context is everything,' Vollmer adds."
How to Find High-Quality Nutritional Yeast
Many people choose nutritional yeast based on its flavor and texture, but it's also important to look at the product's quality. There is, unfortunately, very little transparency when it comes to producing nutritional yeast. It is therefore quite difficult to distinguish high-quality brands from low-quality versions. The most important step will be to contact the manufacturer directly and ask questions, including:
- What is the yeast grown on? If it's grown using GE sugar beets or sugar-beet molasses, skip it. Look for brands grown using sugar cane molasses (although GE sugar cane exists, it's not widely used) or even better, organic sugar cane molasses.
- Are synthetic vitamins added or are they produced naturally? Nutritional yeast varies widely in nutritional content. Some manufacturers add synthetic vitamins at the end of the manufacturing process while others are produced naturally. Ask the manufacturer to explain where the vitamins in their product come from.
- Is it tested for lead? An independent laboratory analysis of eight nutritional yeast samples showed detectable levels of lead in three of the samples.8 The lead levels were low; it would take 6 to 7 tablespoons of the yeast a day to exceed the California Office of Environmental Health Hazard Assessment Maximum Allowable Dose Level (MADL) for chemicals causing reproductive toxicity.
Still, it's better to choose a brand with no detectable lead, so ask whether the brand you choose is regularly tested, has no detectable lead and has a laboratory analysis certificate to prove it.
How to Use Nutritional Yeast — and How It's Produced
Nutritional yeast is often grown in a vat of molasses, nutrients and water. Once it's mature, it's put onto a conveyer belt, dried and broken down into flakes, powder or granules.9 One of the key differences between brewer's yeast and nutritional yeast is their flavor. The former is very bitter and is typically only taken in supplement form.
Nutritional yeast, however, is quite tasty and can be used to add flavor to many foods. When in its dried, flaked form, some people compare it to Parmesan cheese, although it also resembles yellow fish food.
You can find nutritional yeast in most health food stores: it's often sold in the bulk section, although it also comes in jars and canisters. Store the yeast in your refrigerator or a cool, dark cabinet where it will keep for up to two years. You can use nutritional yeast the way you would use grated cheese to add a bit of salty, savory flavor to your meals. It also works especially well when mixed in to or sprinkled on:10
Soups, curries and stews (it will help to thicken and add flavor) Smoothies Vegetable dishes (especially kale, green beans, peas and carrots) Salads Popcorn Garbanzo beans
If you're new to nutritional yeast and want to get a feel for its flavor, try the recipe below—an addictive yet somewhat healthy popcorn treat from Bon Appétit Magazine:11
Popcorn With Nutritional Yeast and Aleppo Pepper
- 2 tablespoons nutritional yeast
- 1 teaspoon Aleppo pepper or crushed red pepper flakes
- 1 teaspoon kosher salt
- 8 cups just-popped popcorn (from ½ cup kernels)
- ¼ cup olive oil
- A spice mill or a mortar and pestle
- Finely grind nutritional yeast, Aleppo pepper, and salt in spice mill or with mortar and pestle.
- Arrange popcorn on a rimmed baking sheet and drizzle with oil; toss to coat.
- Sprinkle with some of the nutritional yeast mixture and toss well to coat, adding more nutritional yeast mixture to taste.