Nutritional Pearls: "Old" Wheat Strains Not Safer for Celiac Disease
John is a 35-year-old man with celiac disease. Recently, he read an article about the history of wheat cultivation and the potential differences between "old" strains of wheat and modern strains. At his most recent checkup, he asks if these older stains of wheat would be safe for him to consume.
How would you advise your patient?
(Answer and discussion on next page)
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Answer: It is unlikely that modern wheat varieties are responsible for the current celiac disease increase
It's true that the rate of diagnosis of Celiac disease has increased in the twentieth century, with some estimates placing the autoimmune disorder's prevalence at 4 times greater than it was 50 years ago. There have been a number of explanations put forth for why that might be, from higher rates of diagnosis (true, but not anywhere near the 400 times higher by some estimates), to people simply consuming more wheat-containing products, to higher levels of the specific protein, gluten, in the wheat we eat today.
After the First World War, scientists began breeding wheat to grow better and to be hardier and shorter (thus easier to reap). Their efforts were most aggressive in the 1950s, about the time that diagnoses of Celiac disease began to increase. While there was clearly correlation between the two, we know that doesn't necessarily mean that one caused the other.
The Research
A team of researchers in Italy decided to investigate whether older strains of wheat (those used before the First World War) were quantitatively different from those strains of wheat used today.1 They noted that when humans digest wheat flour, the proteins in the wheat are broken down into peptides. Some of these peptides have been identified as specifically related to Celiac disease and causing 1 of 2 types of immune responses in humans: either an immunogenic (requiring multiple exposures for reaction) or toxic (immediate) response. Once the different wheat varieties were digested, would the different wheat varieties produce different levels of these peptides? This might be why people were developing celiac disease more often than they used to.
The authors identified 5 different species of wheat grown by commercial farms in 2 different Italian regions, Parma and Bologna, and collected samples of both conventionally- and organically-grown varieties from the Parma region. Three of the species are known as "einkorn," "emmer," and "spelt," respectively, with the first 2 being considered "old" grains and spelt being considered a modern grain. The 2 other species are considered "common" and "durum" wheat, with both old and modern varieties.
Multiple samples of each variety and its old, modern, conventional, or organic varieties were analyzed for their raw protein and gluten content, then run through a standardized process that closely mimics (albeit imperfectly) human digestion. The resulting peptides were then analyzed using liquid chromatography with mass spectrometry to measure, broadly speaking, the immunogenic and toxic peptides in each sample.
The Results
Proponents of organic farming may be surprised to hear that when the authors compared the conventionally-grown wheat with the organically-grown wheat, there was no significant difference between the 2 in the levels of toxic or immunogenic peptides resulting from their digestion. On the other hand, while there were small differences between the different species of wheat analyzed, on the whole the old versions of wheat resulted in slightly (yet statistically significant) higher levels of toxic and immunogenic peptides than the modern versions.
What’s the “Take-Home”?
Obviously, the authors could not test for every single possible peptide that might be related to celiac disease, but the peptides they did test for are fairly conclusively implicated in the immune response experienced by those with celiac disease. They conclude that "it is unlikely that modern wheat varieties are the responsible [sic] of the current celiac disease increase," so those who might be touting a certain strain of wheat—organic or conventional, "ancient" or "modern"—as "safe for patients with celiac disease" should not be trusted.
Reference:
Riddle MS, Murray JA, Porter CK. The incidence and risk of celiac disease in a healthy us adult population. Am J Gastro. 2016;107:1248-1255.