Should you eat sourdough if you have diabetes?

In this article:

• Is sourdough bread good for diabetics?
• Does sourdough bread raise blood sugar?
• Why is sourdough bread good for diabetics?
• Tips for incorporating sourdough into your diet

In this article

• Is sourdough bread good for diabetics?
• Does sourdough bread raise blood sugar?
• Why is sourdough bread good for diabetics?
• Tips for incorporating sourdough into your diet

People with diabetes need to be mindful of what foods and drinks they consume each day since the wrong combination of nutrients could lead to short-term problems, like blood sugar imbalances, as well as long-term problems, like higher risk of obesity, high cholesterol, high blood pressure, and heart disease. “The main [consideration] for people with diabetes is to maintain the right macronutrient balance and avoid high glycemic foods, including refined carbohydrates,” says Inna Melamed, Pharm.D., functional medicine practitioner and author of Digestive Reset.

That doesn’t mean people with diabetes shouldn’t eat any carbs. The American Diabetes Association (ADA) stresses the importance of striking the right balance of carbs so your blood sugar stays within a healthy range (i.e., neither too high nor too low). One way to do that is by consuming more beneficial carbs—and, in good news for anyone who took up baking at home as a pandemic hobby, sourdough bread is a delicious source of good-for-you carbs that raises your blood sugar more slowly than many bread options. Here’s what to know about how sourdough affects the glycemic response and how to incorporate it into a diabetes-friendly diet.

Is sourdough bread good for diabetics?

There are a few reasons why sourdough bread is good for diabetics, especially compared to other types of bread.

• Improved nutrient absorption: Dr. Melamed says that eating sourdough bread leads to better nutrient absorption in the gut, thanks to the acids produced during the fermentation process. That means you get more out of the nutrients found in sourdough and the other foods you eat, too.
• Better gut health: Fermented foods can support your gut microbiome by supplying it with beneficial probiotics—and sourdough is no exception. Studies suggest that the microbes found in a sourdough starter or wild yeast—a live culture of yeast and bacteria that serves as a leavening agent—can improve your digestion and overall gut health. That’s important because gastrointestinal disorders are common among people with Type 1 diabetes and Type 2 diabetes, and some research shows that probiotics are especially good for people with diabetes, contributing to lower blood sugar and insulin levels.
• Increased satiety: Sourdough bread makes people feel fuller after eating it compared to traditional types of bread, says Dr. Melamed, which makes them less likely to crave food again later, potentially assisting with weight loss and maintenance.

Does sourdough bread raise blood sugar?

“Sourdough bread results in a smaller increase in blood glucose levels than industrial bread or pure sugar,” says Kelsey Costa, MS, RDN, a registered dietitian nutritionist and founder of Dietitian Insights, “[particularly] when the sourdough is made with whole wheat flour.”

This is partly because sourdough has a lower glycemic index than commercial breads, many of which have added sugars, Costa explains. The glycemic index measures how quickly a food will raise your blood sugar and how high it might go after you consume it. Combined, these low ratings make sourdough a better option for blood sugar management compared to bread made from other types of white flour, which typically have higher GI ratings.

All carbs raise your blood sugar levels to some degree. Per the ADA, your body breaks carbs down into sugar and then uses that sugar to give you energy. That’s unavoidable and not technically a bad thing—you need the energy you get from carbs! The problem arises when you eat too many refined carbs and sweeteners, which are broken down very quickly and cause your blood sugar and insulin levels to rise rapidly.

You want to avoid these spikes, especially if you have diabetes or prediabetes. Repeated spikes in blood sugar are associated with negative side effects like heart, kidney, and nerve problems. While sourdough will raise your blood sugar levels, it will do so much more slowly than many other types of bread.

Why is sourdough bread good for diabetics?

It’s hard to quantify how good sourdough bread is for people with diabetes. Many factors vary, including the specific microbes in the live culture, the fermentation method, and the type of flour used, says Costa. Still, studies focusing on specific bacteria strains and controlling for fermentation conditions have shown some improvements to participants that could also be beneficial for people with diabetes, such as:

• Improving response to glucose: A 2023 review of studies found some evidence that sourdough bread may be able to make people feel fuller for longer and reduce GI symptoms in people with irritable bowel syndrome (IBS).
• Regulating blood sugar levels: Sourdough bread is also good for people with diabetes because it’s high in resistant starch, a type of starch that doesn’t break down in the small intestine. “Resistant starch is not digested in the same way as other carbohydrates,” says Costa. “Instead, it passes relatively intact through the digestive system, helping to reduce and slow down the absorption of carbs, which can be beneficial for regulating blood sugar levels.”

While whole grain sourdough is a great choice for people with diabetes looking to maintain lower blood sugar levels in spite of their love of carbs, it’s not the best bread out there or the only low GI bread that achieves this goal. Dr. Melamed says many types of multigrain and whole grain bread—like whole wheat bread, whole rye bread, sprouted grain bread, and homemade bread made with gluten-free grains like quinoa and brown rice—won’t spike blood sugar levels like a slice of white bread from the supermarket.

These low-GI breads are among the healthiest carb options for diabetics, thanks to their high fiber content and nutritional value. For tips on incorporating more grains into a healthy eating plan, consult a healthcare provider or dietitian for medical advice.

Tips for incorporating sourdough into your diet

Although sourdough is one of the best types of bread to eat if you have diabetes, that doesn’t give you a free pass to eat as much as you want every day. You still have to consume it in moderation and alongside other nutritious foods, says Costa. The good news is that you could eat one or two slices per day as part of a balanced diet, especially if you find ways to maximize its benefits.

How do you do that? Dr. Melamed says the ideal way to incorporate sourdough bread into a diabetic diet is to combine it with good-quality fat and a good amount of lean protein to offset the (minimal) blood sugar spike. Costa also suggests incorporating lots of plant-based foods and veggies, noting that foods like avocado, eggs, olive oil, and dark leafy greens make perfect accompaniments.

You can also get more out of your daily sourdough fix if you eat bread at the right time. Costa says recent research suggests that people with Type 2 diabetes might have lower insulin sensitivity in the morning compared to the afternoon, so eating sourdough bread later in the day might be better for glycemic control in people with Type 2 diabetes.

Finally, keep in mind that the type of flour used to make sourdough bread can also improve its overall health effects: “Whole grain flour contains more fiber compared to refined white flour, so sourdough bread made with whole grain flour tends to have lower net carbs and a reduced impact on blood sugar levels,” says Costa.

If you have diabetes and are shopping for sourdough bread, look for bread made with whole grain flour, if possible—and if you can’t find any, try your hand at making it yourself! Sourdough comes with a bit of a learning curve, but it’s well worth the effort (for your tastebuds and your blood sugar levels).