Sourdough – What are the Nutritional benefits

A picture a sourdough starer on a board

I am writing this post about the nutritional benefits of sourdough, having been truly inspired after attending a demonstration by a local third-generation baker, to make my own. 

When it comes to bread, it seems the economic, political, and cultural factors have historically pushed aside the nutritional benefits.  However, with the resurgence of traditional bread formats, such as sourdough, nutritional benefit has to be a key factor and maybe will dictate a fairer price.

Unlike other fermented foods, sourdough does not contain live beneficial bacteria or yeast as they are killed during the baking process.   However, fermentation is key in the process of making sourdough and in changing the nutritional properties of the bread.

I have recently encouraged my family members to eat sourdough and here are some of the reasons why.

You may have seen a push in publicity on the risks associated with Ultra Processed Foods ( UPFs).  I shan’t go into detail about that here.  It stood out to me that one of the key UPF’s that we eat, thinking it is healthy, is the humble sliced supermarket loaf.

Move away from ultra-processed foods.

I always encourage you to look at ingredient panels of foods you eat regularly. Here’s a comparison of two breads.

A typical Granary Loaf ingredient panel

Wheat Flour (with added Calcium, Iron, Niacin, Thiamin), Water, Original Granary Blend (Granary Malted Wheat Flakes (11%), Malted Barley Flour, Toasted Wheat, Toasted Rye),  Wheat Protein,  Yeast,  Salt, Vinegar,  Soya Flour,  Granulated Sugar,  Caramelised Sugar, Emulsifier: E472e, Flour Treatment Agent: Ascorbic Acid

A White sourdough ingredient panel

Wheat Flour  (with added Calcium, Iron, Niacin, Thiamin), Water, Salt

The main ingredient, Wheat Flour,  is refined in both these cases. Only wholemeal versions will have wholemeal flour, which will contain the bran fraction of the grain and therefore higher natural quantities of vitamins and minerals. The removal of nutrients during milling has led to the need to fortify the flour,  with what is deemed important for the population’s health. This won’t necessarily replace all the nutrients that are lost in this process and certainly not the all important fibre and phytonutrients.

The point here is, that there are different types of flour used and these will have the biggest impact on the nutritional value of the final product.  Selecting a wholemeal version of flours will therefore increase nutrients and fibre. Using other grains, such as rye, will increase certain nutrients and add to variety in the diet.

Importantly, moving away from UPF’s gives us control back! UPF’s generally manipulate our “Full signals” and tend to make us eat more than we would otherwise. (Note those extra ingredients in the sliced loaf !). Therefore, consider trying Sourdough and see if this helps you control your intake! 

Easy to Digest

The long definition of fermentation is

Fermented foods are defined as foods or beverages produced through controlled microbial growth, and the conversion of food components through enzymatic action.

The slow fermentation which is key to the sourdough process breaks down the the main protein in wheat, gluten and this is thought to be part of why sourdough is easier to digest.  Gluten will not be entirely broken down and the amount of this that occurs will be dependent on many factors in the process.  One of which is how much bran is included as this is thought to contain proteases (enzymes that break down proteins).

The fermentation process has also been shown to convert short chain sugars, which also known as FODMAPs.  As in many fermenting processes, the Lactic Acid Bacteria (LAB) use sugars as fuel and therefore lower the overall levels, potentially making the bread more tolerable to people with IBS symptoms.  Well, that’s the theory.

A recent review paper looks at whether this has a beneficial effect when studied on actual people.  Out of the 25 (542 people) clinical studies that made the grade, 7 (260 people) were focused on gastrointestinal health.  3 looked specifically at low FODMAP and Low Gluten breads. It reported there was conflicting evidence in decreasing GI discomfort in healthy people, there was some evidence of the ability of sourdough to lower the immune response or GI discomfort in those with IBS.  Trials on such things are incredibly difficult to separate a multitude of factors due to the very diverse nature of naturally fermented food.

its complex and dynamic ecosystem requires further standardization to conclude its clinical health benefits. (1)

Improved glycaemic response 

In the same review mentioned above, there has been a great deal of interest in sourdoughs’ advantage in reducing the glucose response which would certainly lead to better health outcomes.  20 of the trials investigated this looking at healthy individuals and those with metabolic diseases

More than 50% of the studies comparing sourdough bread with white wheat bread did not find significant differences in the glycaemic response of healthy individuals between the groups

If you are a glass-half-full sort of person then you could conclude.

Some studies (3) of the nutritional benefits of sourdough bread have found that can lead to more moderate blood sugar responses than eating conventional bread

… as Zoe does. See:

Again, my comment would be that it depends on the individual, what flour you use and, more practically, what you put on your sourdough.

Although I’m a great proponent of the nutritional benefits of sourdough, I’ve only just dipped my toe into some of the complex research. There were over 400 papers on Sourdough in the last 5 years according to Pubmed, indicating that the research world is certainly interested.   I suggest you explore how it works for you, whether you choose to make your own or buy it.


I hope you have enjoyed this if you’ve made it to the end, well done – do let me know  


  1. Nutritional benefits of sourdoughs: A systematic review Lea Ribet 1,y , Robin Dessalles 2,y , Corinne Lesens 1 , Nele Brusselaers 3,4,5 , Micka€el Durand-Dubief 6,* Advances in Nutrition Volume 14, Issue 1, January 2023, Pages 22-29
  2. Sourdough improves the quality of whole-wheat flour products: Mechanisms and challenges—A review Sen Ma, Zhen Wang, Xingfeng Guo, Fengcheng Wang, Jihong Huang, Binghua Sun, Xiaoxi Wang, Food Chemistry,Volume 360,2021,
  3. Bread making technology influences postprandial glucose response: a review of the clinical evidence. Stamataki NS, Yanni AE, Karathanos VT. Br J Nutr. 2017
  4. Yoghurt as a starter in sourdough fermentation to improve the technological and functional properties of sourdough-wheat bread Carla Graça, Minnamari Edelmann, Anabela Raymundo, Isabel Sousa, Rossana Coda, Tuula Sontag-Strohm, Xin Huang, Journal of Functional Foods, Volume 88, 2022,
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