Last updated on June 9th, 2018 at 10:13 pm
Although this blog focuses on vaccines, there are really so many myths and tropes on the internet that are based on the misunderstanding of science, on pseudoscience, or just plain ignorance. One of those myths is that human meddling in plant genetics, which led to modern wheat, is the root cause of all gluten sensitivity, including celiac disease.
Of course, the quack medicine world has vastly overrated the “dangers” of gluten – those with real gluten issues, with properly diagnosed celiac disease and wheat allergies, represent less than 1% of the population. The internet quacks also have no understanding of real gluten sensitivity – it’s an on/off switch. With some relatively rare exceptions, gluten causes significant symptoms in those with gluten sensitivity, not vague feelings. And there’s no dose-response curve – a tiny amount has almost the same effect as a large amount of gluten.
Although I doubt it will have any effect on these anti-gluten food fads, a new peer-reviewed paper in a respected journal clear shows that that modern wheat is not responsible for celiac disease. Gluten from 2018 probably is the same as the gluten in wheat when it was first domesticated 12,000 years ago.
Let’s take a look at celiac disease, wheat, gluten, and the paper. I hope it makes sense.
What is gluten?
Gluten is a protein found in wheat, and similar proteins are also in common grains such as barley and rye. Generally, we like gluten, because it gives elasticity to dough, allowing bread, pizza crust, and other foods to have that chewy texture that is an important component of the pleasure of eating.
Without trying to be a Food Network Star, gluten is critical in baking everything from bagels to cakes. Generally, kneading the dough forms long chain gluten protein molecules that lead to a chewier and chewier texture. Pasta, bread, and so many other foods are made with high gluten flour that is worked hard to create longer chain proteins. Yes, good cooking involves intense knowledge of chemistry.
Gluten can be removed from the milled flour (or it can be added back). Purified gluten, because of its texture, is actually used to create fake meat products, so beloved (or not) by vegans.
So what is the real celiac disease?
Yes, there really are people who are sensitive to gluten. Celiac disease (also known as coeliac disease in British English) is an autoimmune disorder that afflicts the small intestine of certain individuals who are genetically predisposed to gluten sensitivity. The disease afflicts between 1 in 1,750 and 1 in 105 people in the United States (or about 0.05 to 1%), a tiny number.
Celiac disease usually presents, but not always, with chronic diarrhea, low pediatric weight gain, and fatigue in response to gluten. It can also lead to depression. In a small proportion of those with the disease, there may be no symptoms after consuming gluten.
Although celiac disease is not completely understood – when a person, who is genetically susceptible to the disease, is exposed to gluten, their immune system creates an inflammatory reaction in the lining of the small intestine. This interferes with the absorption of nutrients. The only effective treatment at this time is a lifelong gluten-free diet.
This disease should not be confused with a wheat allergy, which is also caused by a reaction to wheat proteins, including gluten. However, there are over 20 different wheat proteins that have identified as causing wheat allergies, and gluten generally is not the cause of wheat allergy. Finally, wheat allergies are extremely rare, and the gluten form of wheat allergies is so rare that it would take a huge population to detect it.
A quick wheat primer
Wheat is a grass, related to other grasses like corn, rice, and barley. Of course, it’s also related to the grass growing on your lawn, wild grasses that form a basis of many ecosystems (think, grasslands), and even bamboo. Grasses are probably the most economically important group of plants in the world.
Wheat was domesticated in the Fertile Crescent in around 9,600 BCE, or nearly 12,000 years ago from wild grasses. Early farmers, practicing bioengineering through artificial selection, would see mutant forms of the grasses that had larger seeds, easier to grow, disease resistance, or other characteristics. They would select the seeds of those plants and use them to grow new crops. Then, the farmers would notice other mutated versions that met some need, and they would grow that in the next year.
This has been repeated for 12,000 years until we have modern wheat. This early genetic engineering has led to various forms of “mutated” wheat, some with quadraploid or hexaploid (2 pairs or 3 pairs of chromosomes) vs the usual diploid (1 pair). Yes, humans have manipulated genes of plants for thousands of years – it’s not something that scientists invented a few years ago.
The first wheat to be cultivated for its gluten content, and used to make bread, seems to be from 1350 BCE in Macedonia, although it may have arisen earlier. At this point, we go to the new scientific article.
Celiac disease and modern wheat – the paper
A paper by Manek Malalgoda et al., published in the respected Food Chemistry, examined the hypothesis that changing gluten proteins in cereal grains like wheat, barley, and rye, from ancient times until now, are the cause of modern celiac disease. Setting aside the fact that we have no evidence that celiac disease is any more prevalent now than it was 3000 years ago, we still can compare gluten proteins today to those from long ago.
These researchers then compared the celiac disease-initiating peptides of α-gliadin, that, along with glutenin, form gluten, in historical and modern spring wheat cultivars. If the gliadins are different in historical wheat than it is in modern wheat, then we might have some biological plausibility that ancient gluten was less immunogenic than current wheat.
To quote Dr. Kevin Folta in a recent blog post in Real Clear Science, a lot of research has been published over the past few years regarding these gluten proteins:
The findings of the most recent work? There is no pattern. Some ancient varieties have high levels, some have low levels. Some modern varieties have high levels, some have low levels.
In other words, this means that historical wheat has a high variability in immunogenic gluten proteins approximately equivalent to what we find today. Malalgoda et al. concluded that:
…total α-gliadin varied randomly across the cultivars that were analyzed, suggesting there is no association between cultivar release year and amounts of immunogenic epitopes and α-gliadin.
Many people have this ridiculous, but enduring, belief that foods were better back in the old days. But study after study shows that’s not true, at least from a scientific point of view. Historically, there may have been more cultivars of food crops, which may have certain environmental and agricultural value, but that doesn’t mean that modern wheat causes more celiac disease than it did hundreds of years ago.
Dr. Folta sums up his blog post with these words of wisdom:
The take home message is that gluten, and its contribution to human digestive ills, does not appear to be a product of modern breeding. While crop improvements like better yields, disease resistance, and the ability to survive weather extremes are easily measured, they did not happen with a parallel increase in gluten proteins.
While it is trendy to blame human participation in plant genetics as the root of all food problems, the data don’t match the allegation. Wheat’s rich genetic history has provided the molecular bones of pasta and bread, and a profitable crop for the farmers that grow it. For the 99% of us that are not celiac-sensitive this is very good news.
Summary
I have a family member who has celiac disease, and I have to constantly refute the nonsense they pick up from the internet (I’m the scientist, they are not). The “modern crop food is dangerous to humans” trope is so annoying, since there is just little evidence of these dangers.
Celiac disease is an extraordinarily rare disease, and even though there seems to have been a rise in real diagnosed celiac disease (not people who make random claims based on how they feel), it is not related to any change in gluten proteins. And no, there is no evidence that there’s more gluten in modern cultivars of wheat either. And there is evidence that we actually eat half as much wheat as we did in 1900.
There does seem to be an increase in diagnoses of autoimmune disorders, including celiac disease, which defies easy explanation – it could be anything from better diagnostic techniques through the controversial hygiene hypothesis. But now we do know that there is no evidence that modern wheat is magically different than historical wheat.
Of course, the pseudoscience-loving crowd will continue to blame gluten on everything, including Donald Trump. Of course, if gluten gave us Trump, then I might have to re-write this article.
Citations
- Di Sabatino A, Corazza GR. Coeliac disease. Lancet. 2009 Apr 25;373(9673):1480-93. doi: 10.1016/S0140-6736(09)60254-3. PubMed PMID: 19394538.
- Malalgoda M, Meinhardt SW, Simsek S. Detection and quantitation of immunogenic epitopes related to celiac disease in historical and modern hard red spring wheat cultivars. Food Chem. 2018 Oct 30;264:101-107. doi: 10.1016/j.foodchem.2018.04.131. Epub 2018 Apr 30. PubMed PMID: 29853353.
