By Christina Manian, RDN Updated on September 12, 2023
Sourdough bread is both nutritious and extremely delicious—here's every reason love this healthy bread.
Sourdough bread baking has skyrocketed in popularity over the last several years (thanks, quarantine). This wholesome baking challenge is a ton of fun and yields extra-delicious results. People love sourdough bread not only for its uniquely satisfying taste and texture, but also for its (often) healthier nutritional profile compared to other types of bread. But is sourdough bread healthy, really? Or at least, is it healthier than other types of bread and baked goods?
Interestingly enough, sourdough bread does boast quite a few health benefits when compared to many conventional bread options found at the grocery store, especially from a digestive health standpoint. So whether you bake or buy your sourdough loaves, read to learn what sets this fermented bread apart, why it’s become so popular, and the health benefits it offers.
What Is Sourdough Bread?
First things first, what exactly is sourdough bread? Like most other breads you’ll find at the grocery store, sourdough is a leavened bread, or one that contains rising agents. But instead of relying on those convenient envelopes of active dry baker’s yeast, sourdough is leavened by something called a starter. Sourdough starter is a living culture of microbes like lactic acid bacteria and “wild” yeast that are cultivated from the flour it’s made with and the air it’s exposed to. These microbes living in a symbiotic relationship thrive on a steady supply of water and flour, and the mixture looks and feels like a thick pancake batter. (Many actually consider sourdough starter to be a diverse microbiome itself, not unlike our gut microbiome.)
When mixed with flour, water, and salt to make bread, sourdough starter ferments the flour in the dough to produce natural leavening. This fermentation also helps to break down some of the proteins found in flour, including gluten (yes, gluten is a protein!).
This method of bread baking has stood the test of time, dating back to around 1500 BC in ancient Egypt. And while this type of bread resembles other loaves you’d see at the bakery or the supermarket shelf, it offers a signature tangy flavor many find to be simply irresistible. This taste is actually due to the acetic acid produced during fermentation.
Is Sourdough Bread Healthy?
After taking just a quick glance at sourdough’s nutrition facts panel, it’s hard to deny its healthy nutrients. In this bread option you’ll find some protein, fiber, iron, selenium, manganese, copper, and B vitamins like B12, folate, thiamin, niacin, and riboflavin. Plus, in whole wheat sourdough bread, there are notable amounts of potassium, zinc, and phosphorus.
The fermentation process involved in sourdough-making combined with the nutrition it offers yields some great health benefits. Here are some of the most noteworthy.
The fermentation required to make sourdough bread starts to break down some of the proteins in wheat flour, including gluten. This yields an end result that is often easier to digest for those sensitive to gluten and other wheat-based products.
Important to note: This bread is fermented, but the microbes present in the bread dough are killed off when baked, precluding it from being considered a probiotic food. That said, many sourdough breads, especially if they’re whole grain, can be considered prebiotic foods—they offer soluble fiber that helps feed healthy bacteria in the gut microbiome. The microbiome is a community of over a trillion microorganisms living in our large intensive and its health is intimately tied to our overall digestive health and regularity.
Speaking of the gut microbiome, our immune health also benefits from the prebiotic support sourdough offers this important microscopic community. This is because the microbiome helps to regulate inflammation throughout the body as well as modulate the mucosal immune system. The biome has even been tied to risk reduction for a host of chronic illnesses. Interestingly, a 2019 study found that older adults living in the Mediterranean who regularly consumed whole grain sourdough bread had a lower risk for chronic illnesses including heart disease, cancer, and diabetes. The immune-boosting mineral zinc found in whole wheat sourdough may also amplify this benefit.
This zesty bread also benefits metabolic health from several angles. Firstly, sourdough has a lower glycemic index when compared to other non-fermented breads. It will result in a lower and slower blood sugar spike compared to other breads, especially if it's whole grain sourdough bread. This means better blood sugar control and longer-lasting energy for those with metabolic concerns like type 2 diabetes—as well as those without diagnoses (minimizing frequent steep blood sugar spikes and dips is beneficial for everyone).
In terms of nutrient availability and absorption, sourdough also has a leg up. Fermentation helps to increase the bioavailability of B vitamins in bread products and can even increase the amount of vitamin B12 present in the final product. This process also helps to break down anti-nutrients like phytic acid, which can inhibit the absorption of crucial minerals like iron. In fact, some evidence points to sourdough fermentation being able to reduce the phytic acid content of bread by over 70 percent.
Sourdough bread’s fiber, potassium, phosphorus, and sodium content all support a heart-healthy diet. The soluble fiber found in sourdough bread binds to dietary cholesterol in the small intestine, helping pass this fat through the system instead of absorbing it. This helps prevent atherosclerosis, or plaque build-up on the veins and arteries, linked with long-term high cholesterol levels that’s often central to heart disease. Also, potassium, phosphorus, and sodium are major electrolytes in the body that help to maintain healthy heart rhythms while potassium is linked to better blood pressure regulation, both core tenants of heart health.
Whole grain and whole wheat sourdoughs offer more healthy nutrients.
If possible, opt for whole wheat or whole grain sourdough, as these will have much higher levels of fiber and micronutrients than their white counterparts. Tip: Look for the word “whole” on the food label—this ensures your bread of choice is 100-percent whole grain or whole wheat.
Give sprouted sourdough a try (for even more nutrients).
It may be harder to find near you, but sprouted sourdough will offer even more nutrition. Sprouting, or germination, increases the bioavailability (aka the absorbable amount) of many micronutrients, reduces glycemic index, lightens gluten load, and breaks down anti-nutrients.
Sourdough bread is not inherently gluten-free.
For those avoiding gluten for personal health reasons, it’s important to note that, even though sourdough bread has improved digestibility for the gluten-sensitive, it is not completely devoid of this wheat protein. Because of this, those with celiac disease or another severe gluten allergy should avoid sourdough bread.