Kathleen,

I wasn’t familiar with yeast protein, so I ran it through past Claude AI. Claude says:

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What yeast protein is: It’s derived from Saccharomyces cerevisiae (baker’s/brewer’s yeast), typically processed to remove the cell wall and concentrate the protein. The “fermented” label mostly just means it’s produced via fermentation, which is how yeast is grown — it’s not fermented in the way, say, tempeh is.

Amino acid profile: The claims are broadly accurate. Yeast protein is a complete protein with all essential amino acids. It has a PDCAAS score of 1.0, matching animal proteins like whey. It does better than pea or rice protein on metrics like methionine content, which is often the limiting amino acid in plant proteins.

Digestibility: In a TIM-1 digestion model, yeast-based protein was comparable to casein and whey in terms of digestibility. That’s a meaningful finding. Processing matters though — in vitro protein digestibility of processed brewer’s spent yeast was almost twice that of unprocessed yeast (73% vs. 40%). The commercial powders are processed, so this works in their favor.

Human trial evidence: One randomized controlled trial had 79 participants consume 40g daily of yeast protein, whey protein, or placebo alongside 8 weeks of resistance training. Both the yeast and whey groups showed gains in trunk and total lean mass, while the placebo group did not. In a subpopulation with inadequate dietary protein intake, both yeast protein and whey protein significantly increased lean mass and muscle strength compared to placebo (https://pubs.sciepub.com/jfnr/12/5/9/). It’s a legitimate piece of evidence — though it was industry-funded (Angel Yeast), which is worth noting as a caveat.

What’s missing: There’s very little independent, non-industry-funded research. Almost all the positive data traces back to Angel Yeast (the ingredient manufacturer behind “AngeoPro”), and there are no long-term trials or head-to-head comparisons with, say, pea+rice blends at matched doses. The brands your reader mentions (Mille, SuperYou) likely use Angel Yeast’s ingredient or something similar.

Bottom line: For someone who needs a convenient, vegan, high-quality protein supplement to hit 1.6g/kg without excess calories, yeast protein is a perfectly reasonable option. It’s complete, well-digestible, and has at least one decent RCT behind it. The superiority claims vs. pea/rice are slightly oversold — a well-formulated pea+rice blend is also complete and digestible — but yeast protein is not worse, and may be mildly better on some metrics. There’s no reason to avoid it.

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I hope that helps!

Bazyliszek

Here’s what the Office of Dietary Supplements says about excessive niacin: https://ods.od.nih.gov/factsheets/Niacin-HealthProfessional/#h16

It seems to me that even a few tablespoons of fortified nutritional yeast per day is safe for adults. But someone taking that much should be aware of flushing, which is defined at the ODS link above.

I’m curious what you think about nutritional yeast flakes as a supplement in a vegan diet. I’m not referring to vitamin B12 here, which is often mentioned in the context of nutritional yeast (as we know, for it to contain B12 it must be fortified). I mean the rest of the vitamins.

According to USDA data*, just a few grams of flakes contain huge amounts of various B vitamins. For example, 3 teaspoons of flakes provide as much as 830% of the RDA for vitamin B1, 780% for vitamin B2, 360% for vitamin B3, and 680% for vitamin B6.

It therefore seems that a small amount of flakes daily can do wonders. This is especially useful for vitamin B2, which can be problematic in a vegan diet.

However, I’m worried whether there might be a risk of overdoing it. For example, the lowest UL for vitamin B3 is 20 mg. So could we potentially reach harmful excess levels of certain vitamins through nutritional yeast?

How many grams of nutritional yeast would you recommend as a maximum per day?

*https://fdc.nal.usda.gov/food-details/1744022/nutrients

Tammie,

Check out our recipe generator.

Sí, es seguro, pero recomendaría obtener al menos 25 mcg por día y quizás hasta 50 si el niño es mayor de 10 años.

Lisa,
Eating more soy would be the easiest way: tofu, tempeh, soy meats. And other legumes. We list them at the top of this page under Protein.