The Fresh Loaf

News & Information for Amateur Bakers and Artisan Bread Enthusiasts

Yeast and health

Eran's picture

Yeast and health


I have just stopped following an alkaline diet which banns yeast consumption. My reasons for stopping were the lack of science behind the approach. However, some things remained with me, like the sugar free part of the diet.

However, for a couple of years now I've been suffering from repeating skin rashes on my legs, which improved dramatically while following the diet. I am obviouly not interested in reversing that process. I have been told that yeast (which feeds on sugar) is not highly recommended untill symptoms are gone.

After reading a few posts here, it seems like some people here are quite educated about the different types of yeast and bateria, and might be able to give me some sound answers.

So I wanted to know:

  1. Will sourdough be better for me?
  2. Is unleavend bread the best?
  3. What about baking powder or self rising flour?

Thank you very much!



PaddyL's picture

You'll find a whole lot of information there.  Sourdough has been touted as being good for anyone who has allergies to commercial yeast; I don't have an allergy, but I love sourdough because it's so low on the glycemic index that I can eat white bread without my blood sugar spiking.

winsey's picture

So calling sourdough yeast free is slightly misleading. I think the main problem is that commercial yeast is almost all the exact same strain and it seems that most things that are commercialised and produced as a monoculture result in people developing food allergies to them. We build up too much of that one specific bacteria in our system and that's when problems start.

in sourdough, the lactobacteria completely outnumbers the yeast (this is why it rises much more slowly and tastes sour) so it generally has less yeast in the finished product than bread baked with standard yeast.

So yes, sourdough is probably a better bet for you than bread made with commercial yeast. At the same time, it might be best for you to eliminate bread again entirely to see if that makes your rash go away. Then slowly reintroduce bread, starting with sourdough and moving on to those made with commercial yeast to see if the symptoms return. That's really the only way you will find the culprit.

BTW - good on you for eliminating the sugar. Any problems with yeast would certainly be made worse with refined sugar in your body.

clazar123's picture

I know that many answers can lay outside standard medical care but it is good to have things checked out medically to rule out easily solved problems. Esp if you follow really drastic dietary changes.

As for food allergies-they can be difficult to pinpoint.Sometimes the reaction doesn't show up for a week or so, sometimes it only shows up if you reach a certain amount taken in,sometimes it show up only if you have several allergans at the same time.Blood and skin testing are not very accurate with food allergies. The best test is the avoidance/overload test but it must be done under medical care, in case the overload part causes lifethreatening reactions.

It took me years to figure out I can't eat  fresh oranges or fresh squeezed orange juice. I can occasionally have a small glass of the reconstitued stuff. My reaction is a series of rashes that last several weeks to months after eating a fresh orange.Very annoying.

As far as yeast being the cause of all man's problems. Hogwash! Yeasts keep us healthy! We have a symbiotic realtionship with it. Does it ever cause problems? Sure it does. BUt it is not responsible for the slew of maladies many of these websites claim.That's marketing at work.

Good luck-enjoy life and live in moderation.


Good for you on removing sugar! I did that several years ago.I believe sugar is very addictive-just like a drug- and it is in everything! I occasionally have a sweet but it is a treat and not oft repeated and usually small. I treat it like an ingredient and not the main attraction.



Eran's picture

First, thank you for your reply!

Unfortunately, I had this rash for a few years. All the doctors I've seen about it, like to prescribe cream/pills. The problem always goes away, and comes back a few months later. I'm just looking for something more permanent that will solve the problem from the root/cause of it rather than cancel the symptoms.

I completely agree with what you say about the difficulty discovering what food exactly disturbs one's immune system. Hard task. I don't even now how to begin. The diet I was on was probably good for it, since it did not include: sugar (from white, to honey, to fruit), mushrooms, corn, refined salt, any fermented product, and yeast. So it sort of covers everything. However, that's a too long list for a diet which has no sound theory to suppot itself.. So I'm not going to bring back the sugar, since as you said, it's a drug, I think a fatal one.

I still don't know if yeast is good or bad.. I'm still trying to figure it out.. I guess it is hard to find objective findings..


Yerffej's picture

Here is a link that may help you in your search for sourdough and health related information.


Eran's picture

Cheers for the link! It was an educating reading material!

althetrainer's picture

Please help me understand why she referred sourdough made from Kumat and rye as true sourdough?  What about sourdough made from whole wheat flour?

Yerffej's picture

I was unable to find the word "true" anywhere in the article.  The author's reference to and preference for rye and kamut is with regard to those with celiac disease.


Eran's picture

Almost forgot. So since the advices basically say, "stay away from yeat for a while", does anyone know much about unleavened breads, and how to make them?


This website is spectacular!

Mini Oven's picture
Mini Oven

They depend on soda and/or Baking powder.  Try looking for Soda Bread, Baking powder biscuits, or Scone recipes.  Also try searching Quick Breads.  Got a cookbook?


bassopotamus's picture

I find it kind of hard to believe that yeast in a finished loaf of bread would do much of anything to any one, given that you cook bread to an internal of about 200F, which should kill anything except those weird undersea things that live in volcano vents, and I certainly hope your bread doesn't have those.

Eran's picture

Completely agree with you.. However, there are a few diets out there which bann yeast. Since I was on one, and it started to get better, I think I should cut off it for a while.

Saying that, I have recently been making a lot of spelt tortillas instead of bread, and they are amazing!

I will try to do further research though on whether or not yeast remains in the finished product!


Yerffej's picture

I believe that this is an issue or sourdough vs commercial yeast.  Sourdough yields a feremented product and yeast does not.  So while the yeast as such may not be bad for you, the final product is not as healthy as a sourdough.


clazar123's picture

Both sourdough and yeast ferment. Fermentation is the conversion of carbohydrates into alcohols or acids. Commercial yeast is just a concentrate of a single family of organisms-sourdough is a blend of many yeasts and lactobacilli. So if fermentation avoidance is the goal, sourdough is not the answer.

THose dietary restrictions you listed above didn't cover much, in the world of allergy. While not everything is known about food allergy, we have come a long way in the last 30 yrs.Unfortunately, there are a lot of opportunists,also, that are taking advantage of people's fears and desparation. Knowledge is power but you have to get good information and it is a process-not a destination. Keep looking and trying.Don't spend your hard-earned money unless the reasoning works and can be validated from other sources-not just anecdotal statements.


This is an excellent article about food allergies :

It also explains a lot about delayed reactions (very common in food allergies)and Elimination Diets, to help pinpoint what is causing you issues. Elimination Diets works by excluding a related class of food from your diet for at least 2-3 weeks before adding them back in an overload dose to try and elicit the symptoms you experienced before.If you find the right food group to eliminate, the effect is usually dramatic. The Process is:

Eliminate suspect food group,feel better and better,feel good,add food back and feel AWFUL.

I don't mean "food group" as "vegetable" or "carbs" but a group of foods that are related botanically and likely to cause reactions due to their similarity of allergens.



This organization is very helpful with how to live with food allergies and has many chapters around the country.


And if Gluten Intolerance is what is happening to you, here is an organization that is helpful:

Good luck.


Eran's picture

I will check all these seem to be very helpful links!

I know that sourdough is fermented as well, but since I heard a lot of people with yeast related allergies manages sourdough, I was interested in more information.

DrPr's picture

Your post was very interesting to me.  I followed a raw foods diet for a while (and still return to it on occasion) and always have the most wonderful health benefits from it.

Anyway, many raw foodists are concerned with creating an "alkaline" body (the validity of this venture notwithstanding) but still consume fermented, acidic foods such as kombucha tea.  It's my understanding that while commercial yeasts prefer more alkaline environments, the wild yeasts found in sourdough starters thrive in acidic environments.