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Have you ever been warned that you should cut bread out of your diet because it’s full of carbohydrates, makes you gain weight, and is bad for your health? If you’re a bread lover, sourdough bread may be a great option, because the health benefits of sourdough bread are numerous.
Sourdough bread’s health benefits make it an excellent and healthy bread choice. Its top benefit? Sourdough bread has a low glycemic index and can help keep your blood sugar and insulin levels lower, which can prevent insulin resistance and diabetes.
What Is Special About Sourdough Bread’s Health Benefits?
All bread is different. What grains are used, how the grains are processed, and the way the dough is prepared and baked all can affect the composition of bread products, and in turn, how they are metabolized in our bodies. This can affect how fast the bread moves through our digestive system once we eat it, and the way our body breaks down and absorbs the starches.
With sourdough, the grain, oftentimes wheat, is fermented with lactic acid bacteria and wild yeasts. In this process, the grain is metabolized by the bacteria and lactic acid is produced. Sourdough has reduced simple sugar content and high levels of lactic acid, which makes it unique from other types of bread.
Studies Show Sourdough Bread Has a Lower Glycemic Response
Most bread products (especially white bread and highly processed bread) are loaded with carbohydrates and the starches are quickly digested. This produces a high glycemic response, meaning that your blood sugar spikes quickly after eating. Elevated glucose in the blood comes along with increased insulin concentrations which can be detrimental to health. But the fermentation process in sourdough lowers the glycemic index and makes it a great low GI bread.
A 2009 study looked into the difference between ingesting white bread, whole wheat bread, white sourdough bread, or whole grain wheat barley bread. Eating sourdough bread led to the lowest blood sugar and insulin levels. Furthermore, the beneficial effect of lowered glucose lasted beyond into the next meal, too.[1,5]
Another study in prediabetic patients found that sourdough bread elicited significantly lower glucose and insulin levels than regular bread. The researchers concluded that a diet including a low gi bread such as sourdough bread might delay the evolution of insulin resistance into diabetes itself.
Even short bursts of high blood sugar can worsen insulin resistance and contribute to diabetes; preventing spikes in glucose by eating sourdough is one of the many benefits of sourdough bread.
SOURDOUGH BREAD… OR EZEKIEL BREAD?
The most nutritional choice for bread? We make the case here for sourdough bread. But don’t overlook Ezekiel bread. Read about the increasingly popular choice here.
Eat Sourdough Bread in Moderation to Replace Other Bread Products
So if you’re continuing to include bread in your diet, it seems that sourdough bread is the best way to go. Try buying a whole grain sourdough bread or make your own at home. (Watch a video with instructions here.)
Eat in moderation, however. Remember that while it may be better than other types of bread, sourdough is still carbohydrate-heavy and does raise your glucose levels.
COUNTERPOINT: ANOTHER PERSPECTIVE ON WHETHER SOURDOUGH IS HEALTHIER THAN WHITE BREAD
Does sourdough bread slow down the rate at which glucose releases into our bloodstream? That belief makes it a healthier choice than, say, white bread. Or at least that’s what some experts have purported. But is it actually the case?
In 2017, a team of Israeli researchers at the Weizmann Institute of Science conducted studies that produced a different conclusion: that sourdough bread doesn’t necessarily have a lower glycemic index for everyone. The effect may be true with some people, but turns out to be opposite for others. In other words, the glycemic response to the two types of bread varies greatly across people, per the small crossover trial.
The researchers’ summary:
Bread is consumed daily by billions of people, yet evidence regarding its clinical effects is contradicting. Here, we performed a randomized crossover trial of two 1-week-long dietary interventions comprising consumption of either traditionally made sourdough-leavened whole-grain bread or industrially made white bread. We found no significant differential effects of bread type on multiple clinical parameters.
The gut microbiota composition remained person specific throughout this trial and was generally resilient to the intervention. We demonstrate statistically significant interpersonal variability in the glycemic response to different bread types, suggesting that the lack of phenotypic difference between the bread types stems from a person-specific effect.
We further show that the type of bread that induces the lower glycemic response in each person can be predicted based solely on microbiome data prior to the intervention.
Together, we present marked personalization in both bread metabolism and the gut microbiome, suggesting that understanding dietary effects requires integration of person-specific factors.
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This article was originally published in 2015 and is updated regularly.
 Br J Nutr. 2009 Feb;101(3):391-8.
 Food Microbiol. 2009 Oct;26(7):693-9.
 J Nutr. 2012 Jul;142(7):1304-13.
 Acta Diabetol. 2008 Jun;45(2):91-6.
 Univeristy of Guelph. News Release. 2008 Jul.