Wheat is among the most destructive components of the human diet, a food that is responsible for inflammatory disease, diabetes, heart disease, several forms of intestinal diseases, schizophrenia, bipolar illness, ADHD, behavioral outbursts in autistic children . . . just to name a few.
But why?
Wheat is mostly carbohydrate. That explains its capacity to cause blood sugar to increase after eating, say, a turkey sandwich on whole wheat bread. The rapid release of sugars likely underlies its capacity to create visceral fat, what I call "wheat belly."
But neither the carbohydrate nor the other components, like bran and B vitamins, can explain all the other adverse health phenomena of wheat. So what is it in wheat that, for instance, worsens auditory hallucinations in paranoid schizophrenics? Is it the gluten?
First of all, what is gluten?
Gluten protein is the focus of most wheat research conducted by food manufacturers and food scientists, since it is the component of wheat that confers the unique properties of dough, allowing a pizza maker to roll and toss pizza crust in the air and mold it into shape. The distinctive “doughy” quality of the simple mix of wheat flour and water, unlike cornstarch or rice starch, for instance, properties that food scientists call “viscoelasticity” and “cohesiveness,” are due to the gluten. Wheat is mostly carbohydrate, but the 10-15% protein content is approximately 80% gluten. Wheat without gluten would lose its unique qualities that make it desirable to bakers and pizza makers. Gluten is also the component of wheat most confidently linked to immune diseases like celiac.
The structure of gluten proteins has proven frustratingly elusive to characterize, as it changes over time and varies from strain to strain. But an understanding of gluten structure may be part, perhaps most, of the answer to the question of why wheat provokes negative effects in humans.
The term “gluten” encompasses two primary families of proteins, the gliadins and the glutenens. The gliadins, one of the protein groups that trigger the immune response in celiac disease, has three subtypes: α/β-gliadins, γ-gliadins, and ω-gliadins. The glutenins are repeating structures, or polymers, of more basic protein structures.
Beyond gluten, the other 20% or so of non-gluten proteins in wheat include albumins, prolamins, and globulins, each of which can also vary from strain to strain. In total, there are over 1000 other proteins that serve functions from protection of the grain from pathogens, to water resistance, to reproductive functions. There are agglutinins, peroxidases, α-amylases, serpins, and acyl CoA oxidases, not to mention five forms of glycerinaldehyde-3-phosphate dehydrogenases. I shouldn’t neglect to mention the globulins, β-purothionin, puroindolines a and b, tritin, and starch synthases.
As if this protein/enzyme smorgasbord weren’t enough, food processors have also turned to fungal enzymes, such as cellulases, glucoamylases, xylanases, and β-xylosidases to enhance leavening and texture. Many bakers also add soy flour to enhance mixing and whiteness, which introduces yet another collection of proteins and enzymes.
In short, wheat is not just a simple gluten protein with some starch and bran. It is a complex collection of biological material that varies according to its genetic code.
While wheat is primarily carbohydrate, it is also a mix of gluten protein which can vary in structure from strain to strain, as well as a highly variable mix of non-gluten proteins. Wheat has evolved naturally to only a modest degree, but it has changed dramatically under the influence of agricultural scientists. With human intervention, wheat strains are bred and genetically manipulated to obtain desirable characteristics, such as height (ranging from 18 inches to over 4 feet tall), “clinginess” of the seeds, yield per acre, and baking or viscoelastic properties of the dough. Various chemicals are also administered to fight off potential pathogens, such as fungi, and to activate the expression of protective enzymes within the wheat itself to “inoculate” itself against invading organisms.
From the original two strains of wheat consumed by Neolithic humans in the Fertile Crescent 9000 years ago (Emmer and Einkorn), we now have over 200,000 strains of wheat virtually all of which are the product of genetic manipulations that have modified the protein structure of wheat. The extraordinary complexity of wheat proteins have therefore created a huge black box of uncertainty in pinpointing which protein causes what.
But there's an easy cure for the uncertainty: Don't eat it.