As discussed in last week’s article, a growing number of people are being diagnosed with celiac disease, a chronic condition in which the immune system reacts negatively to the presence of gluten in the small intestine. There appears to be a genetic predisposition to celiac, but unexpectedly, those most susceptible are descended from European and Caucasian ancestors – the very same people who made gluten-containing grains a staple of their diet, usually in the form of bread. Why would people whose ancestors could tolerate gluten just fine be unable to tolerate it today? This phenomenon has much in common with the history of corn, which traditionally provided sufficient sustenance to Mesoamericans but resulted in nutrient deficiencies among Western Europeans when it was brought over by Columbus. In the case of corn, it was the natural processing method used by the Mesoamericans, but forsaken by the Westerners, that made corn digestible. In the case of gluten-containing grains, the problem again comes down to a change in the processing method.
Ever since the beginning of civilization in the ancient Near East, bread has always been the centerpiece of the diet. Traditionally, to make bread, whole grains were ground into whole grain flour, which was then mixed with water to form dough, and leavened, or allowed to rise. The leavening agent was a portion of a “starter,” a small amount of wet dough that had been colonized by microorganisms already naturally present in the air and on the individual grains: a symbiotic blend of Lactobacillus bacteria and wild yeast (the bacteria far outnumbering the yeast). The yeast would turn the starches in bread into ethanol and carbon dioxide (which enabled the dough to rise) and the bacteria would feed on the yeast’s byproducts, thereby forming sour-tasting lactic acid, which in turn helped protect both the yeast and bacteria from unwelcome organisms such as other forms of bacteria or mold. After sufficient leavening, this “sourdough” bread would be baked. The result was a moderately risen loaf that kept well and was packed full of nutrition. This was the bread that become known as the “staff of life,” and which served as a metaphor for food in general.
Up until the mid-19th century, bread throughout the world was prepared according to this traditional method. However, the new technology that came with the industrial revolution enabled factories to mass-produce bread made with white flour instead of whole wheat, which reduced the nutrient value of the bread. While white flour had previously been a delicacy of the upper class, it now became the standard for all classes, which had a devastating effect on impoverished people who relied on bread as their main source of nutrition.
Meanwhile, advances in science made it possible for bakers to isolate and grow their own strains of yeast, instead of having to rely on wild yeast. With these abundant quantities of yeast, bread products could be made that didn’t rely on bacteria at all for leavening. The result was bread with a sweeter flavor, which, like white bread, appealed to the upper classes, who were already indulging in large quantities of meats that left them craving excessive sweet flavors. When, in the 1850’s, the technology was available to mass-produce this new form of industrial “baker’s yeast,” bread leavened solely with yeast became the new standard, given that baking with it was easier and quicker, it rose more, and didn’t require sourdough starter. Ever since, the standard form of bread that we eat has been white bread leavened with baker’s yeast, due to both its convenience and its immediate gratification.
What does this have to do with gluten and celiac disease? While the transition from whole grain to white flour is part of the problem (due to the loss of nutrients that would otherwise aid digestion of the bread), the main culprit is the transition from sourdough bread to baker’s yeast-leavened bread. The bacteria that used to ferment all our bread just so happens to produce enzymes that help break down gluten proteins. In addition, the lactic acid byproduct weakens the gluten network by increasing the number of positively charged amino acids along the protein chains, and increasing the repulsive forces between chains. A similar process takes place when we soak meat in an acidic marinade to tenderize it: the protein-based tissues break down and the meat becomes more digestible. The gluten in sourdough bread, therefore, is much easier to digest, which explains why our ancestors could tolerate so much bread. True, their bread didn’t rise as much as ours, but they didn’t mind – they tended to eat it with a lot of butter, lard or olive oil, and just a small amount could sustain them for a long time, which reduced the amount of calories they ate overall.
We started turning our backs on sourdough around the year 1850; the first case of celiac was formally diagnosed only a few decades later, in 1887, and the disease has been getting more prevalent since then. To an extent, we are all gluten-sensitive, even if we don’t have readily apparent celiac disease, wheat allergies, or digestive disorders. We’re just not meant to eat large quantities of gluten unless in a form such as sourdough bread. Nevertheless, in the modern world, gluten is everywhere, not just in bread; in fact, it’s extremely difficult to avoid. Fortunately, we don’t need to cut it out completely, or genetically engineer it to be digestible; we just need to go back to eating it in the form that we did, without health issues, for thousands of years. In the next and final installment of this series, I’ll explain how we can change our baking ways to be more in line with traditional methods.