In 2009, Dan Buettner’s invesitgation of “blue zones” — regions whose inhabitants have much-longer-than-average lifespans — took him to the Greek island of Ikaria, where one in three people lives past the age of 90. Buettner identified 13 lifestyle factors that may contribute to the Ikarians’ longevity. Not surprisingly, more than half of these relate to diet. What may surprise you is that one of the dietary elements Buettner claims can contribute to a long and healthy life is sourdough bread.
This is a sound assertion; scientific research on sourdough offers several reasons why sourdough can be health-enhancing. These benefits are probably primarily derived from the acids produced by the lactobacillus bacteria that are an integral component of a sourdough starter and give the bread its sour flavor:
- Sourdough bread has a lower glycemic index — a measure of how high and how quickly blood sugar spikes after eating a food — than bread made with commercial yeast. This makes it a better choice for people with, or at risk for, diabetes.
- Sourdough makes certain minerals (iron, zinc, magnesium, and others) in whole grains more available for absorption by our bodies by facilitating the breakdown of phytic acid, a compound in grain bran that inhibits mineral absorption.
- Sourdough shows promise for people with celiac disease, which renders people intolerant to gluten. Not only can sourdough improve the taste, texture, and overall sensory quality of breads made with gluten-free flours, but it may also act to degrade or deactivate proteins in gluten that adversely affect gluten-sensitive people.
- Sourdough makes people happy, thereby diminishing stress, which is good for all-around wellness. (Okay, this one is anecdotal, but I completely believe it, don’t you?)
Sourdough and cereal fermentation in a nutritional perspective. Food Microbiol. 2009; 26(7):693-9.
Sourdough-leavened bread improves postprandial glucose and insulin plasma levels in subjects with impaired glucose tolerance. Acta Diabetol. 2008; 45(2):91-6.
Use of sourdough lactobacilli and oat fibre to decrease the glycaemic index of white wheat bread. Br J Nutr. 2007; 98(6):1196-205.
Sourdough lactobacilli and celiac disease. Food Microbiol. 2007; 24(2):187-96.
Gluten-free sorghum bread improved by sourdough fermentation: biochemical, rheological, and microstructural background. J Agric Food Chem. 2007; 55(13):5137-46.
The importance of lactic acid bacteria for phytate degradation during cereal dough fermentation. J Agric Food Chem. 2007; 55(8):2993-7.
Moderate decrease of pH by sourdough fermentation is sufficient to reduce phytate content of whole wheat flour through endogenous phytase activity.
J Agric Food Chem. 2005; 53(1):98-102.
Sourdough bread made from wheat and nontoxic flours and started with selected lactobacilli is tolerated in celiac sprue patients. Appl Environ Microbiol. 2004; 70(2):1088-96.