Photo by Tommaso Urli | Unsplash.com

• Share

PRINT

While sourdough might seem like just another type of bread you can make or buy, it actually used to be one of the only options. Until the development of commercial yeasts in the 1800s, sourdough, made with naturally occurring yeasts and lactic acid bacteria, was the main type of leavened bread consumed worldwide.

Sourdough undergoes natural fermentation rather than relying on additives found in baker’s yeast. This means that compared to other breads, it is easier to digest, has less impact on blood sugar and is potentially more nutritious.

Easier to digest

The fermentation process used to create sourdough helps to degrade gluten, a protein found more heavily in grains such as wheat, barley and rye that is resistant to digestion.

In addition to lower levels of gluten, sourdough has lower levels of other compounds known to cause gastrointestinal issues, including FODMAPs, phytates, tannins and trypsin inhibitors.

This means that sourdough may be easier to digest and result in fewer gastrointestinal symptoms compared to commercially leavened bread. A 2023 review of 25 studies bears this out, showing that people reported significant improvements in gastrointestinal comfort switching from bread made with baker’s yeast to sourdough bread.

Maintains blood sugar levels

The fermentation process used to make sourdough produces organic acids, such as lactic and acetic acids, which help slow the absorption of starch in the digestive tract. When food is digested slowly, glucose is released more gradually into the bloodstream, preventing a significant spike in blood sugar levels after eating.

This means that compared to other breads, sourdough is low on the glycemic index (GI), a classification system that ranks carbohydrate-rich foods on a scale of 0-100 according to their impact on blood sugar levels. The GI estimates how quickly food is digested and absorbed into the bloodstream.

The GI for a 30-gram (g) serving of bread made with white wheat flour is 71, while the GI for a 30g serving of sourdough bread is 54.

Improves nutrient absorption

Anti-nutritional factors found in whole wheat or grain breads, such as phytates, tannins and trypsin inhibitors, can make it harder to absorb nutrients from food. Phytates, in particular, can bind to minerals like magnesium, calcium and iron, blocking their absorption in the digestive tract.

The fermentation process used to make sourdough breaks down anti-nutritional factors like phytates. In fact, some studies suggest that certain sourdough formulations can degrade over 96% of the phytic acid in the dough.

Risks of eating sourdough

While sourdough contains less gluten than other breads made with wheat flour, it’s not gluten-free, so it isn’t safe for people with celiac disease or those who are sensitive to gluten-containing foods.

If you’d like to enjoy sourdough but can’t eat gluten, choose a gluten-free sourdough product. Gluten-free sourdough bread is made with gluten-free flours such as those made with millet, sorghum, teff, quinoa and buckwheat.

Keep in mind that gluten-free sourdough will have a different texture than sourdoughs made with wheat flour, as gluten adds a chewy, airy texture to baked goods.

Health delivers relevant information in clear, jargon-free language that puts health into context in peoples’ lives. Online at Health.com.

© 2025 Dotdash Meredith. All rights reserved. Used with permission. Distributed by Tribune Content Agency, LLC.