The Fresh Loaf

News & Information for Amateur Bakers and Artisan Bread Enthusiasts

Nutritional Value of Yeasted Bread?

arhoolie's picture

Nutritional Value of Yeasted Bread?

The following quote was made in an article on sourdough bread making at

"In books on baking and even in nutritional/medical writings, the two techniques [for making bread], natural leaven (sourdough) and baker's yeast, are often mingled and confounded.... Baking with natural leaven is in harmony with nature and maintains the integrity and nutrition of the cereal grains used.... The process helps to increase and reinforce our body's absorption of the cereal's nutrients. Unlike yeasted bread that diminishes, even destroys, much of the grain's nutritional value, naturally leavened bread does not stale and, as it ages, maintains its original moisture much longer."

It's attributed to a Jacques DeLangre, Ph.D.

This one's news to me and while I'm all for naturally leavened breads, (and have been making my bread that way for several years now) the quote above sounds highly suspicious to me.  The part that particlularly struck me was the claim that "naturally leavened bread does not stale" (mine does) and "yeasted bread ... diminishes, even destroys, much of the grain's nutritional value".

Has anyone else heard these kinds of claims before?  Is there any kind of peer reviewed research to support DeLangre's statements?

The full article is at the link above.


sphealey's picture

=== You quoted "... "In books on baking and even in nutritional/medical writings, the two techniques [for making bread], natural leaven (sourdough) and baker's yeast, are often mingled and confounded.... Baking with natural leaven is in harmony with nature and maintains the integrity and nutrition of the cereal grains used...." ===

My first thought is "integrity of the grains"?   Hmm...

Nutrition is a very complex, very poorly understood subject that interacts with the infinitely variable human body.  Which itself is... very complex and very poorly understood.  With 6 billion people on the earth, of many different genetic and environmental backgrounds, the possible variations on how bodies work and use (or misuse) food and nutrients is beyond infinite.

So I tend not to be too taken by the "miracle food" (or "miracle diet") gurus who claim to have knowledge of a specific food, method of food preparation, or eating habit that will either prolong or shorten your life.  Human variation alone works against such theories, and the science if any tends to be various dubious.

If there are any general rules about food and nutrition out there I think they tend to follow a few general guidelines (some taken from Michael Pollen):

  • Eat less food, most of it plants (MP)
  • Avoid [as much as possible] things in the grocery store your great-grandparents wouldn't recognize as food (MP)
  • Cook as much of your food as possible yourself from basic ingredients (MP and sPh)
  • Avoid transfat and HFCS like the plague (sPh)
  • Everything in moderation, including the application of this statement (sPh)
  • Eat foods you enjoy (sPh)
  • There's no point in living to 110 years old if you don't experience any enjoyment along the way (sPh)

As far as yeast breads go, any bread you make yourself from good-quality ingredients is going to test better and probably be a "better" food than anything you buy at the grocery store.  So if you like that type of bread, go for it! 


Do give sourdough a try at some point though; it is quite good and different from yeast bread.

LindyD's picture

While sourdough takes longer to stale, it still does go stale.

Never heard of DeLangre; a quick Google search shows he wrote a book advocating sea salt, claiming that lots of it is good for you, and that a low salt diet causes high blood pressure.

Just because it's on the Internet doesn't make it true.  Charlatans abound.

Ford's picture

I would questioon that there is a great difference between the nutritional value of bread made from "natural leaven" and baker's yeast.  Both yeasts are natural.  The sourdough has additional bacteria that convert some of the carbohydrates to lactic acid and to acetic acid.  I agree with both sphealy and lindyd.  Just because someone has a Ph.D. doesn't make him (or her) infaliable.  I should know -- I too have a Ph. D.


flournwater's picture

Much of what I've read in recent years regarding food health is based upon supposition, junk science, or motivated by the need to sell a book or alternative "health food" product.  Most of it has been pure nonsense.

"Unlike yeasted bread that diminishes, even destroys, much of the grain's nutritional value, naturally leavened bread does not stale and, as it ages, maintains its original moisture much longer."

IMO, that statement is far outside of the bounds of probability.  All bread, even "naturally" leavened bread, gets stale and because yeast feeds on simple sugars to produce carbon dioxide the nutritional value in the grains "destroyed" would be confined to those sugar molecules.  Anyone needing to increase their intake of simple sugars in their diet would be among a very rare and unique group of humans.  In his book, "On Food and Cooking" Harold McGee explains that all bread will stale and that the staling of bread is attributable to starch retrogradation.  Furthermore, as Dr. Ford has already pointed out, "Both yeasts are natural".


clazar123's picture

the guy is nuts. (Jacques, I mean)

maryserv's picture

When I heard absolutes like that, I always want to know the research behind it.  I've found several scholarly journal articles about this that I am going to peruse.  In the meantime, is there a nutritionist out there that can contribute to the conversation? 

There are some parts of the original article that are true and could be a basis for the other claims.  Sourdough does stay "fresh" longer, and molds much more slowly.  The longer fermentation times required for sourdough may do some other things to the grain that can't be accomplished when using commercial yeast because of the time factor involved. 

We know the comment about the "alive" vs. "dead" is dead wrong (pun intended).  Just think about the different between a packet of yeast that is "alive" vs. one that is "dead".  They behave VERY differently!  (which is why proofing of commercial yeast used to be/can be so important); that depends on how frequently you turn over your yeast! 



maryserv's picture

Being a trained Medical Librian, I know full well the dangers of going off of ONE or a few studies to make claims and recommendations.  Here is a study abstract that could have been used to form this basis.  Note that the study specifically addresses the bioavailability of nutrients in WHOLEMEAL grain bread:

"Whole wheat bread is an important source of minerals but also contains considerable amounts of phytic acid, which is known to impair their absorption. An in vitro trial was performed to assess the effect of a moderate drop of the dough pH (around 5.5) by way of sourdough fermentation or by exogenous organic acid addition on phytate hydrolysis. It was shown that a slight acidification of the dough (pH 5.5) with either sourdough or lactic acid addition allowed a significant phytate breakdown (70% of the initial flour content compared to 40% without any leavening agent or acidification). This result highlights the predominance of wheat phytase activity over sourdough microflora phytase activity during moderate sourdough fermentation and shows that a slight drop of the pH (pH value around 5.5) is sufficient to reduce significantly the phytate content of a wholemeal flour. Mg “bioaccessibility” of whole wheat dough was improved by direct solubilization of the cation and by phytate hydrolysis." J. Agric. Food Chem., 2005, 53 (1), pp 98–102. Accessed 02/14/2010 at 

I'll look for more, this is fun, and I get to use my degree!  : )


maryserv's picture

"This study evaluated a typical commercial yeast manufacturing process for bacterial contamination. Product line samples of a commercial yeast manufacturing process and the corresponding seed yeast manufacturing process were obtained upstream from the final compressed and dry yeast products. All samples were analysed before (non-PI) and after preliminary incubation (PI) at 37 °C for 24 h. The PI procedure was incorporated for amplification of bacterial counts below the lower detection limit. Enterococcus, coliform and Escherichia coli counts were quantified by standard pour-plate techniques using selective media. Presence at all stages and progressive increases in counts of Enterococcus, coliforms and E. coli during processing in the commercial manufacturing operation suggested that the primary source of contamination of both compressed and dry yeast with these bacteria was the seed yeast manufacturing process and that contamination was amplified throughout the commercial yeast manufacturing process. This was confirmed by surveys of the seed yeast manufacturing process which indicated that contamination of the seed yeast with Enterococcus, coliforms and E. coli occurred during scale up of seed yeast biomass destined as inoculum for the commercial fermentation." International Journal of Food Microbiology Volume 94, Issue 1, 1 July 2004, Pages 23-31.

Read the abstract, it is basically something that we risk when we eat anything that is prepared elsewhere.  There are also dangers with sourdough - especially if one is not observant in what their SD starter should look or smell like.

maryserv's picture

Acta Diabetol. 2008 Jun;45(2):91-6.

Sourdough-leavened bread improves postprandial glucose and insulin plasma levels in subjects with impaired glucose tolerance.

Maioli M, Pes GM, Sanna M, Cherchi S, Dettori M, Manca E, Farris GA.

Institute of Internal Medicine, Metabolic Unit, University of Sassari, Viale San Pietro, 8, 07100 Sassari, Italy.

Sourdough bread has been reported to improve glucose metabolism in healthy subjects. In this study postprandial glycaemic and insulinaemic responses were evaluated in subjects with impaired glucose tolerance (IGT) who had a meal containing sourdough bread leavened with lactobacilli, in comparison to a reference meal containing bread leavened with baker yeast. Sixteen IGT subjects (age range 52-75, average BMI 29.9 +/- 4.2 kg/ m2) were randomly given a meal containing sourdough bread (A) and a meal containing the reference bread (B) in two separate occasions at the beginning of the study and after 7 days. Sourdough bread was leavened for 8 h using a starter containing autochthonous Saccharomyces cerevisiae and several bacilli able to produce a significant amount of D-and L-lactic acid, whereas the reference bread was leavened for 2 h with commercial baker yeast containing Saccharomyces cerevisiae. Plasma glucose and insulin levels were measured at time 0, 30, 60, 120, and 180 min. In IGT subjects sourdough bread induced a significantly lower plasma glucose response at 30 minutes (p = 0.048) and a smaller incremental area under curve (AUC) delta 0-30 and delta 0-60 min (p = 0.020 and 0.018 respectively) in comparison to the bread leavened with baker yeast. Plasma insulin response to this type of bread showed lower values at 30 min (p = 0.045) and a smaller AUC delta 0-30 min (p = 0.018). This study shows that in subjects with IGT glycaemic and insulinaemic responses after the consumption of sourdough bread are lower than after the bread leavened with baker yeast. This effect is likely due to the lactic acid produced during dough leavening as well as the reduced availability of simple carbohydrates. Thus, sour-dough bread may potentially be of benefit in subjects with impaired glucose metabolism.

maryserv's picture

Ok, I've researched enough...I think that there are some benefits to using SD fermentation vs. Commercial yeast because of the presence of lactobacillus bacteria.  That is the greatest benefit of sourdough vs. commercial yeast IMO.  There are many studies showing the benefits of LB on our immune systems, specifically in the GI tract.  Just think about all those yogurt commercials and that will help one understand better I think. The GI tract is our most important system for immunity.  (I can find several references if you want them).

So, I guess if someone has immunity-related absorption problems or GI issues, the presence of the LB would definately increase the nutriative of the bread eaten and perhaps other foods eaten at the same time.  Also, it does show the decrease of insulin response. 

So, I'm gonna keep on doing my SD baking and be happy. 

That was fun!


GlendaLynne's picture

Thankyou Mary.  I really appreciate the effort you went into here.

Lady of the Lake's picture
Lady of the Lake

Your question is the reason I got started reading the forum. It was my question, too. I found several studies and one especially touches on and explains everything mentioned here. I don't seem to have the link, but will find it again. I saved it and would be happy to share. I don't know if it is ok to give our email addresses, but here it is: <>. The article is saved in a .doc format that I could share as an attachment.

The article title says:

Sour Dough Bread and Health
by Mark Sircus Ac., OMD
International Medical Veritas Association

One of the things that really impressed me was " Storage methods for breads that contain no additives are very important to maintain freshness and to avoid spoilage. The staling process begins for regular yeasted bread as soon as the bread is removed from the oven. Sourdough bread on the other hand increases in nutritional value for days. Freezing bread prevents microbial spoilage. Baked bread can be kept frozen for three months without losing flavor. Interestingly, slightly stale bread is more easily digested than fresh bread, up to ten days, after which there is a reversal (Jackel et al., 1952). When I used to make sourdough bread I would make many loafs but would wait two days before freezing any of them to let the natural yeast continue to work in the bread". I found the info fasinating!

Dillbert's picture

.... that is not a doctor.

for every duck in existence there exists one or more internet quacks.


holds the honorary title of doctor of Oriental medicine and was one of the first nationally certified acupuncturists in the United States.


please note "honorary" - and various other obscure references to his expertise.

as with most snake oil salesman, one need not venture far from the self-authored praise to find the $99 ebook, etc.

you will also notice that his entire practice is outside of the USA - I suspect else wise he'd be arrested and prosecuted for his "medical miracle claims"


Lady of the Lake's picture
Lady of the Lake

Thank you for watching out for me when I am being gullible! I should known better by now. I just am so convinced that whole grain sourdough products are exceptionally healthy, that I was too trusting when I read the article. I appreciate your input :)


maryserv's picture


The very first documentation I found regarding this was from a study reported in the Journal of Agricultural Science (think that is it).  The info from that article does support in several ways that wholemeal bread that is leavened with natural leaven rather than commercial leaven is more bioavailable. 

Oriental medicine and complementary/alternative medicine is not all sham.  There have been countless studies on this recorded on PubMed. 

The key to verifying information found online such as this is to research the references.  Do this if it is important to you.  Research has been going on since the protiolytics have been available to test the various forms of protein in foods, check ideal ph levels for absorbtion, etc.  This is not new science or new information that wholemeal is better than that stripped of the germ.  Now, there is further research on what needs to be done to enhance the absorbtion of all the good stuff in the grain.  Food chemistry/science is a pretty cool area of importance in our time in history. 



Dillbert's picture

I doubt few main stream or non-mainstream medical / nutritionist people would dispute that whole grains are good for you.

I do have to wonder about "natural leavening" - assuming by "natural leavening" it is meant allowing dough to pick up yeast from its environment.  it is a completely uncontrolled process - yeast fungi of every type and sort abound everywhere - the conclusion is that all "natural" yeast is "better" than "commercially cultivated" yeast is a pretty big generalization.

the role of trace elements in human health are hardly unknown to modern science.  I dimly recall organizations such as the FDA have issued multiple statements regarding eating a healthy and balanced diet.  the FDA also recognizes that individuals with specific medical conditions are more prone to have issues with or from specific trace element deficiencies - hardly any news there.

Sircus is widely referenced on the web by many many "alternative" medicine sites - but not by  researchers who rely on proven science and peer review - here's an extract from his writings:

A neurologist ordered tests. They showed Matthew's blood was laced with mercury in amounts nearly double what the Environmental Protection Agency says is the safe level for exposure to the metal. Matthew had mercury poisoning, his doctors said.
The Davises had pinpointed the suspected source: tuna fish. For a year or so, starting in late 2002, Matthew had gobbled three to six ounces a day of white albacore tuna. Based on Food and Drug Administration data for canned albacore, he was consuming a daily dose of mercury at least 12 times what the EPA considered a safe level for a 60-pound child. The Davises' doctors' prescription was simple: Matthew should stop eating canned tuna.

I don't think the tuna is the root cause of this kid's problem - and I don't think the solution is to eat more baking soda or take magnesium supplements either.  the kid's problem was a poor choice of parent(s)

 that the FDA and big pharma are "hiding" a miracle cancer cure - just eat more baking soda - is ludicrous to say the least.  to believe all of the thousands of labs/organizations researching cancer treatments world wide have all been suppressed from "revealing the true cure" is unrealistic.

Sircus also rails against the use of anti-biotics - again hardly any news here - even the most stuffy medical haunts have been speaking out on dangers and results of anti-biotic "over use."

here's his 'rationale'

The Journal of the American Medical Association has reported a study on 10,000 women in which women who took over 500 days of antibiotics in a 17 year period (dubbed 25 plus doses) had twice the risk of breast cancer as those that took none at all. Even women taking just one had a statistical risk increase to 1.5 times.

 let me pose a question:  why would a woman take anti-biotics for 500 days?  the link was broken, I did not find the details of the study - but a course of anti-biotics is typically 5 - 10 days.  so that's between 50 and 100 anti-biotic prescriptions.  the math isn't pretty.  one is left to wonder what medical condition prompted so many prescriptions.

I was personally acquainted with a Swedish fellow - who after Chernobyl was so paranoid about "radiation poisoning" he rigorously followed a selenium supplement plan (another of this author's favorites) - according to directions.  he wound up in the hospital, and died, from selenium poisoning.  his particular body chemistry reacted adversely to even the "recommended" dosage.  the lesson may be:  self-dosage is not always a good thing.

one might reach the conclusion I'm alternative medicine phobic, which is not true.  a basic tenet of such strategies is simple: eat right, exercise, you'll stay healthy and won't need medications.

there are outside influences to that approach - get a nasty gash that becomes infected?  well, mind over matter might work, and certainly in the pre antibiotic era people did recover from infections - but many did not.
what I find highly questionable are the self-proclaimed "experts" which toss up a lot of stuff that sounds good, and oh-by-the-way, buy my tonic / book / supplement for more warm fuzzies.

Sircus does have his detractors even within the alternative stream:
Mark Sircus Ac., OMD is a New Age "World Psychologist" , by his own proclamation. The Medical News Commentaries are no longer hosted on this server.


maryserv's picture

I think we can all agree that there are quacks out there who are either ill informed but throw their opinions out there anyway, or that are trying to sell something. 

To the OP and anyone else who cares, Debra Wink wrote and posted of Fresh Loaf an outstanding biochemical/microbiological explaination of the processes in sourdough.  Go to her blog and read it.  She has references from reliable sources. 

I noticed last night that a loaf of sourdough rye I made 2 weekends ago was still wonderfully fresh and delicious.  We finished it with dinner last night.  I kept it in a Bread Bag that I bought at Sur la Table by Best Solutions for the Kitchen.  I couldn't believe it!  Rye is a different animal than wheat, so I don't know what will happen with a loaf of Wholewheat or white sourdough.  I have a loaf of Chocolate Bread that I converted to a sourdough and came out delicious.  I'll put some of that in the bag and see how long it stores.  It does have some oil and granulated sugar, so that may extend the "softness" but increase the time to molding.  I'm not sure. 

All I know, is I personally get more shelf life out of my sourdough, and that it doesn't sit at the bottom of my stomach like store-bought bread does.  My yeast breads begin to stale and/or mold so much more quickly as well. 

 Happy Baking!


Dillbert's picture

heehee -ain't that the truth.

maryserv - I am not even remotely questioning your own personal experience.
one does stuff, one experiences "something" - it's valid; period, end of statement.
what I am wondering about is the relationship between "it does not go stale" and "nutritional value"

ala the old "Twinkies have a 1000 year shelf life" urban rumor - ah, not true - the how it's made foodtv segment "did" Twinkies and they publicly stated their shelf life - don't recall exactly what it was, but it was not 1000 years.

so whole gains have more better stuff than bleach white stuff, nadda' problem on my part.

that uncontrolled unidentified unspecified "natural yeasts" make for better nutrition is suspect, in my mind, because there's a whole lotta' yeasties running around in my kitchen and I doubt the research has identified and "tested" all of the naturally occurring yeast strains vs commercially cultivated strains.

that "natural yeasties" produce some by-product that retards spoiling is an interesting and plausible theory.  obviously every different yeastie has the potential to produce different by-products.
but that does not automatically link "never goes stale" to "better nutritional value"

I personally cannot even begin to speak to how fast bread goes stale.  I bake, my problem is the bread gets inhaled / consumed before it has a proper chance to cool !  I'm always on the "don't cut that yet" war path - spoilage / going stale is not an issue around here and I don't have a lab to analyze how digestible / available nutrients are at any given stage of staleness.
nor does it address the question:  are any of those mystery nutrients absent in an otherwise balanced diet?  how's that go . . "man does not live by bread alone" . . .?

that is an important question because the human body generally excretes "not needed" / excess nutrients.  the human body is a pretty dang good machine.  feed it too much of a good thing and it just ignores the excess input.  feed it too much of a bad thing, well . . . nuts, consequences may differ.

it's like the kid in reference - make a tuna sandwich and figure out how many ounces of tuna are in the sandwich.  the kid was eating 3 to 6 ounces of tuna every day.  how many tuna sandwiches is that and what else was the kid eating? 
any parent that feeds their kid 10 sliders a day for a year is, uhmmm, suspect in my opinion.  sliders, happy meals, twinkies, breaded chicken tenders, ice cream, doughnuts - doesn't matter.  that is not a balanced dietary intake.

maryserv's picture

I think that you are addressing the exaggerated claims made by some of these wanna-be nutrional pied-pipers.  I'm simply stating that I found several scholarly, reliable, valid, study-based articles in recognized scientific journals stating that the big difference between bread made with Commercial yeast and bread made with SD yeast is the presence of LB bacteria in SD bread and resulting chemical differences in the two types of bread. 

These differences appear to be beneficial in the study subjects according to the Scientific Method of research.  That is all.


Dillbert's picture


I was just trying to figure out the relationship between bread that never goes stale:


sourdough rye I made 2 weekends ago was still wonderfully fresh and delicious.


because it is made with natural yeast vs

bread that goes stale because it is made with commerical yeast

and the nutritional values of the variants.

and yes, I did go off on a tangent in my last.

I bake all kinds of breads. 

stuff like a no-knead which is just flour, water, salt & yeast - does not go "stale" so fast as for example a Joy of Cooking white bread plus.  should it ever have such a chance, I should add.

what this tells me is that wild vs cultivated yeast is not the only factor in bread going stale - because I use yeast from the same bag for both.  I have no experience using my kitchen wild yeast for either/any bread variety.

but I do not understand the theory / relationship:

"wild yeast doesn't go stale therefore it is better for you"

if that is in fact the intent of the communication.  which freely it may not be . . .

maryserv's picture

I think the OP was questioning whether the claim that SD raised bread is more bio-available (read "better for you") than commercial-yeast raised bread.  A bunch of posters said that the claim couldn't be true and claimed the proponent a snake-oil salesman.  I simply looked up publicly available databases to see if such studies had taken place and found many, then posted them.  

The delay in staling is just another indicator that there is chemical difference between the the two types of leaven.  All other things being equal, according to the liturature (meaning scientifically-based liturature) AND my own personal experience (and others' as well) bread with SD leaven has a delay in spoilage that commercial yeast does not. 

Go to your local libraries online database collection, Pubmed,, or other scholarly/academic database and search for the info yourself.  There is a lot out there.

Dillbert's picture

actually I don't have a problem "believing" the claim - as you said earlier nutruition is not 110% "understood" and you've pointed out the evidence that supports it.

I think what many folks are stumbling on is the idea that "commercial" yeast cannot produce a similar result.  I wonder if the end effect is more due to the extended times / cold fermentation / [whatever] typically used for sourdough than the specific strain of yeast involved.

the primary reason for my (albeit minor) quibble with the "natural" yeast theory is simply there are tens/hundreds/thousands (?) of "natural yeasts" floating around, they do vary by geography and environment, and it seems a stretch to say "all the yeasts to the exclusion of commercial yeasts" produce that result.

over the years I've seen posts by sourdough bakers to the effect they bought some "geniune" SF sourdough starter but over time the specific twang of the SF starter "changed" - accompanied by the theory that "local" yeasts invaded / took over the starter and changed its taste.

an experiment is conceptually simple - innoculate a starter with commerical yeast and see what happens.  the tricky part in a home seeting is excluding all 'foreign' yeast.