Today’s blog is about a question I saw pop up recently on our Beauty Detox Foods Facebook page— and that question is whether nutritional yeast is really good for you — or not!
As someone who has consumed nutritional yeast for years without any problems (and many apparent health benefits!), I want to address many of the myths and misinformation floating around about this superfood. So I’m going to address them all to the best of my ability, along with providing some research and nutritional science, right here in this post.
The first half of the post will explain what nutritional yeast is, how it’s made, and why may be helpful — and then the second half will address some of the criticisms against nutritional yeast, and why I think they’re largely unfounded.
Are you ready? Great — let’s get going…
The Origin of Nutritional Yeast
Yeast has a history that dates back as far back as the ancient Egyptians, at least in terms of food preparation. When most people think of yeast, they are referring to the active form of yeast used to leaven bread. Nutritional yeast is different in that it’s heated and inactive. Remember that distinction as it will be come important later on in this post.
There are two main types of nutritional yeast that often get interchanged:
Brewer’s yeast. This type of yeast is grown from hops (a by-product of brewing beer), and has been around since beer making began… and can be consumed by humans or used to fortify other products or even given to pets. The other is…
Pure nutritional yeast. This is usually grown from sugar cane, beat molasses or wood pulp. And it’s grown specifically for the purpose of human food consumption.
Yeast is a single celled microorganism that feeds offer sugar. 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.
Why Eat It?
Nutritional yeast has often been referred to as a superfood, and for good reason! It is very rich in many basic nutrients such as:
- A full spectrum of B vitamins
- Chromium, which can aid with weight loss
- Sixteen different amino acids, excellent for muscle-building and repair
- Over fourteen key minerals
- Seventeen vitamins (not including vitamins A, C and E).
- Rich source of phosphorous
The vitamin content is especially important, for many reasons that I’ll explain throughout this post.
Why We Need B Vitamins More Than Ever
Nutritional yeast is rich in Thiamin, Riboflavin, Niacin, Vitamin B6, Folate and often Vitamin B12 (more on this one in a moment.) These are all B vitamins that work as a complex, essentially providing you with energy and helping you to maintain proper brain function. Among many other important function, they are also essential for beautiful, healthy hair (which I know we do all care about!).
In fact, B vitamins “wear many hats” in terms of their role in our body. In addition to energy production, brain function and rebuilding of hair, they also have an impact on our fat burning, sleep and much more. What’s more, B vitamins are often depleted during stress — which all of us face more than ever — and some of us more than others! This makes the need for daily consumption of B vitamin-rich foods all the more important. B vitamins can also be depleted from eating junk foods.
B12 for Vegans?
A deficiency in B12 can be identified by symptoms of fatigue, vision problems and soreness of the mouth. B12 helps create strong hair, nails and skin and it helps to maintain a healthy digestive system. B12 reduces fatigue and regulates our central nervous system, minimizing stress. As with other B vitamins, your gut can manufacture and synthesize missing components of the complex when your inner ecosystem is balanced with a healthy ratio of probiotics.
It has been long believed that nutritional yeast contains vitamin B12, naturally — but that is not true. Unlike other microorganisms, such as probiotics, yeast cannot produce vitamin B12. The reason many nutritional yeast products contain B12 is that they are fortified with it at the end of the process. This is not necessarily a bad thing, because it means that you’re still getting B12 at the end of the day.
Ultimately, as a vegan I would not rely solely on nutritional yeast for my B12 needs. Because it is such an important vitamin and there’s more risk for us who don’t eat animal products — I think a more multi-faceted approach for B12 is best.
Personally, I recommend getting the right kind of probiotics, nutritional yeast, sea vegetables and algae such as spirulina, and most likely a B12 supplement just so that you’re never at risk of being deficient.
Excellent Source of Easy-to-Digest Protein
Another big positive about nutritional yeast is that it contains 71% protein, by weight. That is very impressive for a plant food — and its balanced amino acid composition, coupled with its protein ratio can help your brain, body and muscles tremendously.
I personally love this about nutritional yeast, because so many of the quote “high protein” foods for vegans or vegetarians are actually higher in fat or carbs. For instance, nuts and seeds are often praised for their protein content, but they contain much more fat than they do actual protein.
Legumes, such as beans and lentils, are also praised for their protein content but they in fact contain much more carbohydrates than protein. 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.
What the Research Says
While this article has focused on nutritional yeast, most of the history and research has been conducted on its cousin, brewer’s yeast. Still, because their nutritional compositions are very similar, we can extrapolate similar claims/benefits for nutritional yeast based on these studies.
One of the earliest pieces of research came from around the time of the Spanish Civil War. During the second winter of the war in 1937, there was a widespread deficiency of niacin (vitamin B3) — called “pellagra” — along with many neurological disorders.
By giving victims B3, they were able to treat the pellagra. However, the neurological disorders showed no improvement. That changed. however, once they began giving the patients brewer’s yeast. The conclusion of this research was that the neurological issues present were not the result of B3 deficiency, but rather to lacking a key element of the B complex that was present in the brewer’s yeast. 
There was also an Australian study where children with phenylketonuria had low blood levels of selenium, which is a critical anti-cancer mineral and antioxidant that has largely gone missing from the food supply. After taking brewer’s yeast daily for six months, the children were tested again and found that the 50mcg inside the servings of brewer’s yeast raised their selenium levels. 
Last, there was a study done on an elderly group with eight mildly non-insulin-dependent diabetics, where they were fed brewer’s yeast — which as we learned earlier is rich in chromium. The results were that for all individuals, insulin output decreased and blood sugar sensitivity improved. Cholesterol and total lipids also dropped, which could help explain the weight loss component of nutritional yeast. 
An excellent summary of these three research pieces and the study citations can be found here.
WAIT! Isn’t All Yeast Bad for You?
Almost every body has some yeast in and on it. It’s found in oral cavities, the digestive tract, and even on the skin. In a healthy biological system, the presence of helpful bacteria keeps yeast in balance. If you’ve ever taken a course of antibiotics and then suffered a yeast infection, then you are aware of some of the consequences that occur when your body gets out of balance.
Post-antibiotic yeast infections occur because antibiotics kill off more than just the harmful bacteria in your body. They also kill beneficial bacteria. The result is often Candida overgrowth.
Candida is definitely a bad yeast. Candida robs your body of essential nutrients like iron and other minerals and helps keep your blood very acidic. Unless its source of food is eliminated, Candida Albicans can take over and slowly destroy your digestive system, your immunity, and drain you of your energy and health — often leading to the following symptoms:
- Tiredness after eating
- Constipation, diarrhea, or other forms of bowel irregularities
- Feelings of anger, depression, aggression, or anxiety after eating
- Mood swings
- Brain fog
- Cravings for simple carbohydrates
- Anal itching (um, let’s avoid this one, please, as it’s not so becoming, is it?)
- Skin infections
- Memory loss
- Night sweats
- Food allergies
- Feeling “drunk” after a high simple carb meal
- Repeated fungal infections like jock itch or athlete’s foot
- Joint pain
- Sensitivity to extreme environments
- Chronic pain
- Acid reflux
Candida albicans overgrowth may be a major player in a number of health conditions, such as irritable bowel syndrome, alcoholism, anxiety disorders, food allergies, multiple sclerosis, asthma, and a host of other autoimmune conditions.
That’s the Bad News, The Good News Is…
Nutritional yeast is an entirely different strain of yeast — also known as Saccharomyces cerevisiae — and bears no relationship or connection to candida. In addition to being a different strain, it’s heated and therefore not an “active” yeast. Therefore, it has no effect on candida whatsoever, positive or negative. Your body treats it just as it would any other food.
While there are those who argue that nutritional yeast is not well-tolerated by those who have Candida albicans overgrowth, there is no science or research to support this — and not even a scientific explanation. Because the yeast is deactivated, what we have left in the finished product is just an assortment of vitamins and minerals, plus macronutrients such as protein, carbs and a little fat.
Always remember: just because a food or beverage contains yeast, or uses yeast in its processing, that doesn’t mean it’s a bad yeast. Nutritional yeast is proof of that.
Too Much Phosphorus?
Some critics argue that nutritional yeast contains too much of the macro-mineral, phosphorous.
From the book, Healing with Whole Foods:
“Yeast is exceptionally rich in certain nutrients, and deficient in others that are needed for balance. The high phosphorus content of yeast, for example, can deplete the body of calcium; thus some yeast manufacturers now add calcium also.”
The reasoning here is that phosphorous is an acid-forming mineral, and too much of it can create a pH imbalance where then the body needs to use up its calcium reserves to balance things out. This is one of the biggest problems with soda, which is high in phosphoric acid, and leaches calcium.
The problem here is that nutritional yeast is not that rich in phosphorous, not like soda. So you’d really have to consume a lot of it each day for it to become an issue. What’s more, many often consume nutritional yeast with calcium-rich foods, so it balances out. For instance, I rarely have nutritional yeast without Kale — as in my Dharma’s Kale Salad — and kale is one of the plant kingdom’s richest sources of calcium. So as long as you keep this in mind, you should be fine.
The last — and perhaps scariest — critique of nutritional yeast is that it contains MSG-like compounds, and MSG is a well known excitotoxin that damages the brain.
Therefore nutritional yeast damages your brain, right?
Not so fast!
Nutritional yeast is different than yeast additives, often referred to under strange names such as “autolyzed yeast extract” and others.
Natural yeast, without additives, contains approximately 6 to 11% naturally occurring glutamic acid, one of the nonessential amino acids, since our bodies can produce it.
Our bodies are meant to be able to handle a certain amount of this form of glutamate. It is in a bound form, which is naturally broken down into its free form so that it can enter the bloodstream and be released by the liver to be used by the brain.
Glutamate receptors have more recently been located in many other parts of the body, including the lungs, the breasts, heart and joints. When naturally occurring glutamate is broken down as it should be, slowly and as nature intended, there shouldn’t be a problem, unless we are born without the ability to process glutamate correctly.
The problem most likely lies in the fact, that today, we are bombarded with processed foods that contain several sources of free, i.e. processed glutamate, which is the harmful and excitotoxic component of MSG.
It is harmful because it is a form that needs no digesting, allowing large amounts into the bloodstream immediately, and also because it contains other forms of free glutamate, such a pyroglutamic acid, and D- glutamic acid and carcinogens. Actually, our brains have many receptors for glutamic acid and some areas, such as the hypothalamus, do not have an impermeable blood-brain barrier, so free glutamic acid from food sources can get into the brain, injuring and sometimes killing neurons.
So free glutamic acid is a real and legitimate concern — please know that I’m not dismissing that. In my research, however, nutritional yeast is not rich in this artificially added/produced form of free glutamic acid and is therefore not in this category. It is the many other forms of artificial “flavoring” and yeast extracts found in processed foods that we should be avoiding.
No More Nutritional Yeast Myths
Hopefully this article helps you understand everything you need to know about nutritional yeast and dispelled some myths about why it may be bad for you. I realize I’ve given you a lot of information, so please take time to read through it carefully and please definitely let me know if you have any questions.
Anecdotally, I want to conclude by saying that I’ve personally been consuming nutritional yeast, very regularly for years, and I’ve experienced no issues at all. If anything, I feel stronger, healthier and more mentally sharp than ever before.
So this experience, coupled with the research and nutritional information I’ve provided is what causes me to feel comfortable recommending it to you and our community.
Of course, the underlying truth of all nutritional advice is that, as you become more sensitive to the effects of different foods and learn to listen to your body better and better — you’ll instinctively know when a food works well in your body. Or when it’s time to eliminate it.
Nutritional yeast works for me, and ultimately, it’s up to you to determine whether it’s the best thing for your body.
Thanks again for reading and being part of this super awesome community, and look out for more great stuff from us this week!
References Grande Covian F. Vitamin deficiencies during the Spanish Civil War in Madrid: a reminiscence. Acta vitaminologica et enzymologica (1982) 4(1-2):99-103.  Lipson A, et al. The selenium status of children with phenylketonuria: results of selenium supplementation. Australian paediatric journal (1988) 24(2):128-31.
 Offenbacher EG, Pi-Sunyer FX. Beneficial effect of chromium-rich yeast on glucose tolerance and blood lipids in elderly subjects. Diabetes (1980) 29(11):919-25.