What are the Health Benefits of Sourdough Fermentation?
The traditional sourdough baking process have existed since antiquity, but has been cast aside for the quicker, higher yield and more profitable alternative, the quick rise yeast, which reduces the nutritional content of the bread along with making it harder to digest. The quick rise yeast has taken the place of the long fermentation process and this is one important reason for the rise in digestive symptoms from bread eating.
The Sourdough baking process is making a return, and it is transforming the way that we digest bread. Limited ingredient sourdough fermented bread contains flour, water, salt and a sourdough culture starter. A typical loaf of grocery store bread could contain up to 26 ingredients or more, many of which are chemicals.
Sourdough wheat bread which is made by a slow fermentation process with lactobacilli and other beneficial bacteria and fungi, has the ability to actually improve the digestibility of the bread. The prolonged leavening process allows the bacteria and yeast in the culture plenty of time to ferment carbohydrates including fructans and other FODMAPS (FODMAPS are simple carbs and other sugars that can lead to gastric discomfort particularly bloating, abdominal pain and altered bowel function and conditions such as irritable bowel syndrome). Because gluten containing grains, like wheat, are naturally high in FODMAPS, some individuals believe that they have gluten sensitivity when in fact they have FODMAP sensitivity. The microbes in the sourdough culture starter, however, gobble up the FODMAPS before they get anywhere near our digest tract making sourdough fermented bread easy on the stomach. There is also some evidence that the slow fermentation of the bread breaks down or converts some of the gluten proteins over time as well. Many people with non-celiac gluten sensitivity can tolerate this bread just fine. There is still gluten in the bread, however, so those with celiac disease will still want to avoid sourdough fermented bread.
Other benefits of sourdough bread include increased bioavailability of nutrients and a lower glycemic index. The abundant branched chain amino acids (BCAAs) in sourdough fermented bread stimulate the muscle in a similar way as exercise, thereby improving the body’s ability to digest and metabolize the bread.1 In other words, it has a healthier, lower glycemic load, making traditional sourdough bread actually protective against diabetes and insulin resistance. Additionally, the sourdough culture has a high quantity of lactic acid which breaks down the naturally occurring anti-nutrients in the wheat, i.e. phytic acid, thus making the nutrients in the wheat more available to the body. A note of caution, however, is not all sourdough bread is real cultured sourdough. Some loaves are made with commercial yeast flavored with acetic acid. In other words, it is a quick fermented white bread with flavor to simulate sourdough. Don’t let that bread fool you. Find a baker of Real sourdough bread or learn to bake it yourself because it is worth the effort to go out of your way to have this nutritious, low glycemic index, highly digestible bread that I commonly recommend to my non-celiac “gluten” sensitive or gluten avoiding patients.
1. Koistinen VM, Mattila O, Katina K, Poutanen K, Aura AM, Hanhineva K. Metabolic profiling of sourdough fermented wheat and rye bread. Sci Rep. 2018;8(1):5684.