Is there a link between sourdough bread and diabetes?

Eleven million Canadians live with diabetes or prediabetes. Those with diabetes can’t produce insulin or properly use the insulin it produces. Insulin is a hormone the pancreas produces. It regulates the amount of glucose (sugar) in the blood.

Regulating our blood sugar ensures our body functions properly. Too much blood sugar can cause damage to organs, blood vessels, and nerves. We also need insulin to use sugar for energy.

Refined or processed sources of carbohydrates such as white flour, cereals, white rice, potatoes, and pasta can have the biggest impact on blood sugar for people with type 2 diabetes because they can spike blood sugar levels. This can lead to an assumption they should avoid eating many carbohydrates.

Could sourdough bread help manage diabetes?

Fortunately, sourdough bread can be good for people who have or are predisposed to diabetes. Research suggests not only is sourdough an ideal part of a balanced diet, but it can also help to manage blood sugar levels and provide other benefits, which is important when dealing with diabetes.

Many types of breads are available and have varied nutritional value. Highly processed white breads are not healthy—for anyone. Breads with whole grains—especially those produced through a long and slow fermentation as with sourdough—are high in fibre and contain micronutrients in a form that can be more easily digested.

It will take time to discover the bread that’s suitable for you. Homemade breads and loaves or those from artisanal bakeries like ours are less processed and won’t contain additives (including sugar) common in industrial breads.

Insoluble fibre (which can’t be digested by the human gut) found in breads made from whole grain flours is important in promoting a healthy gut microbiota. Diverse and healthy microbes in our gut have positive effects on our health. Insoluble fibre provides food for these microbes. They aid digestion and support a healthy immune system.

In a study linking the actions of gut bacteria with people at risk of type 2 diabetes, higher blood levels of indolepropionic acid were associated with those who did not develop diabetes. Our gut bacteria makes indolepropionic acid. These acid levels appeared to be positively linked to the amount of fibre and whole grains in the study participants’ diets.

Fermentation methods and the way flour is milled influence how we digest bread and assimilate it in our bodies. A Canadian study found blood sugar levels in overweight men showed a smaller spike after eating sourdough bread when compared with yeasted breads. Additional research suggested sourdough breads made with flours milled from sprouted grains are even more beneficial than either white or wholemeal sourdough bread.

Eating whole grain or sprouted grain sourdough breads can moderate blood sugar response. Sourdough’s fermentation process and fibre can have benefits for digestion and the immune system.

Along with a whole-food, plant-based diet, sourdough can help to slow down the rate of assimilation of carbohydrates. Keeping your blood sugar levels even can also lower inflammation and hormone fluctuations.

Visit our rotating sourdough bread schedule. You can also learn our favourite dutch ovens for baking sourdough, and how to store sourdough bread & keep it fresh.