When You Eat Sourdough Bread Every Day, This Is What Happens To Your Body

When thinking of sourdough bread, your mind might wander to slow-paced lifestyles when baking homemade bread was a common practice, or perhaps it takes you to your new favorite brunch spot where you discovered this tasty bread served as a side with everything on the menu. However, what you might not know is that sourdough bread is believed to date back to civilizations as early as 4,000 BCE (via Bakerpedia). Like most breads, sourdough bread is made with flour, water, and salt. Yet, it differs from regular or modern-day breads in its leavening process, which also happens to be what sets it apart in taste, texture, nutritional profile, and potential health benefits.

According to a review published in Foods, unlike modern breads, which are made with single-strain commercial yeasts to leaven the dough rapidly, sourdough bread is characterized by its natural leavening process, a slow and complex procedure involving a mix of flour and water fermented with natural or wild yeasts consisting of multiple strains and lactic acid bacteria. This mix of fermented ingredients is called a starter, which is then mixed with fresh water, flour, and salt to make the bread (via BBC Good Food). Therefore, instead of getting a soft and uniform modern-style bread, this process produces a bubbly bread with a tangy flavor and chewy texture. Moreover, it is due to the said fermentation process that the bread is attributed with numerous benefits, such as longer shelf life, ease of digestion, and higher nutrient availability. Keep reading to discover what happens to your body when you eat sourdough bread daily, which includes these benefits and more.

Every time you eat carb-rich foods, such as bread, they will have an undeniable effect on your blood sugar, causing it to rise. However, the effect is known to differ between foods, and it can be measured or determined by a food's glycemic index (GI). Per Healthline, foods with a high GI cause a rapid increase in blood sugar levels, while those with a low GI cause a slower, more gradual increase, which prevents your blood sugar from spiking and then crashing. 

According to a review published in Foods, unlike many other types of bread that can cause a rapid spike in blood sugar, sourdough has a lower GI thanks to its unique fermentation process. This can be explained due to numerous factors. On the one hand, sourdough fermentation reduces by 50% the amount of rapidly available starch, turning sourdough bread from a high-GI bread to a low-GI one. In addition, the process also helps reduce the rate at which glucose is absorbed into the bloodstream, resulting in bread with a much lower impact on blood sugar compared to regular bread. On the other hand, the fermentation process also takes care of your blood sugar by increasing the bread's fiber and resistant starch (RS) content. Like fiber, RS avoids digestion and finally gets fermented in the large intestine, where it acts as a prebiotic. This not only improves digestive health but also contributes to reduced blood sugar levels after a meal.

Sourdough bread may be easier to digest than other types of bread, mainly due to the fermentation process that reduces its gluten content. Gluten is a protein present in wheat, barley, and rye, and it is responsible for giving bread its elastic and chewy consistency. However, some people may have a hard time digesting it, such as those with celiac disease and gluten sensitivity, to name a few. This may lead to discomfort, bloating, digestive issues, and other potential health complications (via Medical News Today).

Yet, even if made with wheat flour, the fermented starter in sourdough bread helps break down some of its gluten content, making it more tolerable for some people. According to a study published in Frontiers in Nutrition, this is because the fermentation process has the ability to change the structure of wheat components that would otherwise trigger an inflammatory and immune reaction, making the bread easier on the stomach of those who experience digestive issues with other types of bread. Yet, the study notes that there is a lack of research to fully validate this claim. Plus, keep in mind that sourdough bread still contains gluten, so it may not be suitable for everyone with gluten-related issues or following a strict gluten-free diet (via Healthline).

One significant benefit of eating sourdough bread is the improved absorption of nutrients, thanks to the fermentation process that reduces the content of phytates and other anti-nutritional factors (ANFs), which can limit the nutritional value of bread. According to a study published in Nutrients, phytates are naturally occurring compounds in cereals and grains that bind to minerals, including iron, zinc, potassium, calcium, copper, manganese, and magnesium, making them unavailable for absorption. For this reason, phytate is often referred to as an anti-nutrient. However, a review published in Foods explains that sourdough fermentation can break down phytates by up to 97%, significantly reducing their levels, while a study published in Grain & Oil Science and Technology reports a 12% reduction in phytic acid content.

Per the review, the fermentation process, along with the microbes from the starter, creates an acidic environment that enhances the activity of enzymes in charge of degrading phytates, thereby freeing up the bound minerals and making them readily available for absorption. Moreover, the review adds that other ANFs in wheat flour, such as raffinose, condensed tannins, vicine and convicine, saponins, and trypsin inhibitors, also get degraded or destroyed during sourdough fermentation. This means that eating sourdough bread may support your mineral intake, making it a more nutritious option compared to other modern types of bread.

As with most fermented foods, eating sourdough bread can support your gut health due to its probiotic and postbiotic content, which have positive effects on the gut microbiota — the community of gut-friendly bacteria living in your digestive tract. According to a review published in Fermentation, probiotics refer to live microorganisms, such as the lactic acid bacteria and yeast present in sourdough starters. In contrast, postbiotics are beneficial byproducts of the fermentation process. While the review explains that probiotics don't survive the baking process, you can still reap their health benefits when consuming the bread, thanks to the remaining postbiotics.

Probiotics are known to contribute to a balanced gut microbiota by promoting the growth of good bacteria and hindering the growth of harmful ones. For example, according to a study published in Nutrients, test-tube results showed an increase in bifidobacteria in stool samples after exposing them to sourdough bread. Bifidobacteria are healthy bacteria that support gut health by aiding digestion, producing essential nutrients, and boosting the immune system (via Healthline). However, there isn't enough evidence to validate whether this effect also happens when eating the bread. On the other hand, per another review published in Nutrients, postbiotics have been shown to support gut health by reducing inflammation and enhancing the gut barrier. Thus, the combination of probiotics and postbiotics in sourdough bread helps create a favorable environment for your gut.

By adding sourdough bread to your diet, you're actually increasing your antioxidant intake, which can help protect your body from oxidative stress and reduce the risk of chronic diseases. Antioxidants are compounds that neutralize free radicals — unstable molecules that damage cells in your body and can contribute to aging and various diseases, including heart disease and cancer (via Medical News Today). Yet, through its unique fermentation process, sourdough bread naturally increases the levels of these protective compounds, making it a better source of these health-promoting compounds than regular or modern bread.

As a study published in Grain & Oil Science and Technology explains, grains are rich in a type of compound known as phytochemicals, which basically means plant chemicals. These plant chemicals, which include flavonoids and non-flavonoid phenols, have antioxidant properties, and grain fermentation helps increase both the amount present in grains as well as the amount available for your body to absorb. According to a review published in Nutrients, this is because fermentation converts antioxidants in grains from their conjugated or less accessible form to their free form. In addition, enzyme activity during this process helps break down the grain's cell walls, which also makes antioxidants more available for your body to absorb and use. Thus, eating sourdough bread every day is a delicious way to boost your antioxidant intake.

If you have irritable bowel syndrome (IBS), non-celiac gluten sensitivity (NCGS), or simply struggle with bloating after eating bread, sourdough bread might offer a more digestible alternative. This is, once again, thanks to the effect of sourdough fermentation on wheat's FODMAP content. According to a study published in Nutrients, FODMAPs (Fermentable Oligosaccharides, Disaccharides, Monosaccharides, and Polyols) are a group of short-chain carbohydrates found in many foods, including grains, fruit, dairy, and some veggies, that can be difficult for some people to digest. Thus, when the undigested carbs reach the gut, they are fermented by the gut microbiota, leading to symptoms like bloating, gas, and discomfort. Nevertheless, sourdough fermentation plays a major role in reducing the levels of FODMAPs in bread, namely its fructan content, a type of fermentable oligosaccharide.

For instance, per a study published in Frontiers in Nutrition, bacteria and yeast in sourdough can help degrade fructans in wheat flour by up to 95%. Moreover, another article published in Frontiers in Nutrition notes that not only does the type of leavening agent affect the bread's FODMAP levels, but the fermentation time also adds to the effect. Per the article, unlike breads leavened rapidly with commercial yeast, sourdough fermentation takes far longer, typically around six days. This means that instead of getting a limited degradation, sourdough bread provides a more thorough one, thus making it not only a delicious choice but also a friendlier option for your digestive system, allowing you to enjoy bread with greater comfort and ease.

Enjoying a daily serving of sourdough bread might help you consume fewer preservatives than regular bread. This leads to a reduced artificial additive intake thanks to the bread's fermentation process, which allows it to naturally extend its shelf life. The extended shelf life means you can enjoy your bread over several days or weeks without worrying about it going stale or moldy as quickly as other breads might. As a study published in Microorganisms explains, sourdough's fermentation offers two pathways for this effect.

On the one hand, it leads to the production of lactic and acetic acids, both of which acidify the dough by reducing its pH levels, making it harder for unwanted microorganisms, such as mold or bacteria, to survive and spoil the bread. On the other hand, the lactic acid bacteria in sourdough starter produce antimicrobial compounds that further inhibit the growth of potentially harmful microorganisms, adding to the bread's natural preservative effect. In fact, according to a review published in Fermentation, just adding 20% of sourdough to bread can extend its shelf life by roughly six days, while upping it to 30% may increase it to up to 21 days. Per the review, the bacterial strains present in the starter also influence the bread's shelf life, with dough fermented with Lactobacillus showing the best results. Therefore, sourdough bread comes up as a more wholesome or cleaner option.

When you eat sourdough bread, you might be supporting your heart health in ways you didn't expect, seeing that research suggests that sourdough bread may have blood pressure-lowering and cholesterol-lowering effects, which are crucial for maintaining a healthy heart. On the one hand, according to a review published in Nutrients, sourdough fermentation's effect on the bread's taste might help produce baked goods with a lower sodium content. Per the review, the tanginess of the bread allows breadmakers to use less salt in the bread-making process without sacrificing its flavor.

On the other hand, a study published in Foods determined that sourdough bread had higher levels of compounds that inhibit the enzyme angiotensin-converting enzyme (ACE). ACE regulates blood pressure by narrowing blood vessels and increasing fluid volume, which effectively increases blood pressure. Thus, sourdough may act as a blood-pressure-lowering mechanism by blocking its effect. Moreover, the review explains that probiotics in fermented foods like sourdough bread increase your gut's production of short-chain fatty acids (SCFAs), which provide cholesterol-lowering effects. In fact, according to another review published in Advances in Nutrition, while some studies didn't find any cholesterol-reducing effects, others reported a significant reduction in both total and LDL (bad) cholesterol levels after whole wheat sourdough bread intake.

Sourdough bread can be a particularly appealing option for those seeking to boost their nutrient intake through plant-based sources, seeing that, according to a review published in Nutrients, its fermentation process can increase the availability of various vitamins, including vitamin B12 or cobalamin. Vitamin B12 is essential for many bodily functions, including the formation of red blood cells, DNA synthesis, and maintaining a healthy nervous system. Yet, it's mainly found in animal products, making it difficult for those following plant-based diets to get it through natural sources (via the National Institutes of Health Office of Dietary Supplements).

However, a study published by the University of Helsinki suggests that when grain-based products are fermented, they can significantly increase their vitamin B12 content. On a similar note, a study published in Grain & Oil Science and Technology adds that fermenting whole-grain products also increases the availability of other B vitamins, including thiamin or vitamin B1, riboflavin or vitamin B2, and folate or vitamin B9. Nevertheless, the study warns that baking might reduce the bread's vitamin B12 to some extent, meaning you cannot rely on sourdough bread to meet your daily cobalamin requirements. Still, while sourdough bread isn't a significant source of vitamin B12 compared to animal products, it can contribute to your overall intake, especially if you follow a vegan or vegetarian diet.