Dan Buettner Says Sourdough Is A "True Longevity Food" & Here's Why 

If you're familiar with longevity expert, National Geographic fellow, and founder of Blue Zones Dan Buettner, you likely know: He's a fan of beans. So much so, he says 1 cup of beans a day can add around four years to your life expectancy. 

Simple: Sourdough is technically a fermented food. "Sourdough bread is leavened not just with yeast but lactobacillus, and in the process, most of the glutens are neutralized," says Buettner. And like other fermented foods, sourdough is stellar for gut health; in fact, this fermentation process has actually been shown to assist digestion1—that's why some people with gluten sensitivity might actually have a more favorable reaction to sourdough, as the fermentation transforms the bread and causes the gluten to diminish substantially. A 2012 study even showed that lactic acid bacteria in sourdough can release antioxidants during this fermentation process2. 

"And we don't exactly know why, but when you eat a plant-based meal with sourdough bread, the glycemic index of that meal goes down," Buettner continues. "So the sugars in that meal are absorbed more slowly," and your body is more likely to use those sugars for energy (rather than storing them up in your system). So not only does the bread itself have a lower glycemic index than others, but it may have the ability to lower the glycemic index of the entire meal (albeit, we need more research to uncover that benefit).