Tag Archives: Intolerance

Chemical exposure, not just genetics, could induce gluten intolerance

The risk of developing celiac disease (the most extreme form of gluten intolerance) in young people seems to be associated with elevated blood levels of toxic chemicals found in pesticides, nonstick cookware, and fire retardants.

A new study from the NYU Grossman School of Medicine suggests that children and young adults with high blood levels of dichlorodiphenyldichlorethylenes (DDEs), a class of chemicals associated with pesticides, were twice as likely to be diagnosed with celiac disease compared to their peers. Celiac disease is an immune disorder that creates severe reactions in the gut to foods containing gluten.

Gender matters, too

“Our study establishes the first measureable tie-in between environmental exposure to toxic chemicals and celiac disease,” says senior study author and pediatric gastroenterologist Jeremiah Levine, MD.

“These results also raise the question of whether there are potential links between these chemicals and other autoimmune bowel diseases, which all warrant close monitoring and further study,” says Levine, a professor in the Department of Pediatrics at NYU Langone.

The team analyzed chemical levels in the blood of 30 children and young adults (aged 3 to 21), who were newly diagnosed with celiac disease at NYU Langone Hassenfeld Children’s Hospital. The results were compared to a similar analysis of 60 young people of similar age, gender, and race.

The authors report that men and women react differently to such exposure to toxins. Women make up the majority of celiac cases, they note, and the team found that they were eight times more likely to develop gluten intolerance following higher-than-normal exposure to pesticides.

Furthermore, young women with elevated blood levels of non-stick chemicals known as perflouoroalkyls (PFAs) — including Teflon — were five to nine times more likely to have celiac disease.

Young men with high blood levels of of fire-retardant chemicals polybrominated diphenyl ethers (PBDEs) were twice more likely to be diagnosed with celiac disease.

The study didn’t establish a clear cause and effect relationship between these chemicals and celiac disease, but the authors note that they are all known to disrupt animal and human hormone levels, which are key to controlling both sexual development and immune defenses against infection. The authors call for more in-depth research on the topic.

Our understanding up to now is that celiac disease, which affects around 1% of the world’s population, is largely genetically-driven. However, if other studies support the results of this study, it could radically alter our understanding of this condition, alongside other autoimmune disorders.

The paper “Persistent organic pollutant exposure and celiac disease: A pilot study” has been published in the journal Environmental Research.

Baked cake.

What is gluten intolerance, and what are its symptoms?

Gluten is a protein naturally found in cereals such as wheat, barley, and rye. Harmless for most of us, gluten can cause quite a lot of headache (and bellyaches, among other things) for certain people. Today, we’ll take a look at the different kinds of gluten intolerance and the symptoms they can cause.

Baked cake.

Gluten makes dough elastic, knead-able, and bouncy. You can see how it works in this cake, keeping those stringy bits in the middle from breaking.
Image credits Andreas Lischka.

Wheat (genus Triticum) makes the world go round. Not literally, but it does play a big role in keeping us humans fueled up. It was one of the first domesticated food crops, and for roughly 8 millennia now, wheat has been the staple food of major civilizations in Europe, North Africa, and West Asia. More land area is dedicated to growing wheat than any other commercial crop on Earth, and global production of wheat outstrips that of any other crop — including rice, maize, and potatoes.

Barley (Hordeum vulgare) is another long-time companion of human farmers. First cultivated around 10,000 years ago, it was the fourth most-produced grain in the world in 2016, although output has somewhat declined since then. Barley is very useful as an animal feed but is perhaps most celebrated for its role in beer and distilled beverage production.

Both of these cereals, along with rye, their related species, and various hybrids, are part of the grass (Poacea) family of plants. Altogether, they supply a huge part of the calories and nutrients consumed by us and our livestock. They also supply the majority of raw materials used in producing alcohol.

Apart from their economic importance, these crops are also notable for their high content of gluten and gluten-like proteins. This is a bit of a bummer for around 1.5% to 14% of the world’s population, who have to contend with various forms of gluten intolerance.

What is gluten intolerance

Gluten intolerance is a somewhat-umbrella term that refers to adverse reactions to gluten. I say ‘somewhat-umbrella’ because it tends to be improperly applied to several conditions that — while similar in effects — are different in origin. These include celiac disease (CD), non-celiac gluten sensitivity (NCGS), wheat allergy, dermatitis herpetiformis, and (more rarely) gluten ataxia.

The most extreme form of gluten intolerance is celiac disease (also known as gluten-sensitive enteropathy, sprue, or coeliac). Roughly 1 in 100 Americans contend with CD, and this percentage seems to hold true for the rest of the world as well. CD is basically an autoimmune disorder. The body of a CD patient reacts with extreme violence to the presence of gluten in one’s food — to the point where their immune system will attack the inner lining of the small intestine to ‘protect it’ from gluten. Such offensives cause immediate symptoms for the patient. If exposure to gluten is maintained over a longer period of time, sustained damage to the gut’s lining leads to problems in absorbing nutrients (malabsorption).

Celiac disease gut lining.

High-magnification image of intestinal lining damaged by celiac disease.
Image credits Nephron / Wikimedia.

Non-celiac gluten sensitivity is more controversial. We don’t know, really, what causes this condition (or if it’s even an actual thing). Our best guess is that it has something to do with gluten-associated proteins and/or other chemical compounds present in gluten-containing crops. Since we don’t know what causes it and how, NCGS is generally diagnosed by eliminating other possibilities (namely CD and wheat allergies). Roughly 0.5% to 13% of the world’s population has NCGS. While its exact symptoms are debated, NCGS seems to share most gastrointestinal symptoms of CD, wheat allergies, and irritable bowel syndrome, but with a different interval between exposure and onset of symptoms. NCGS also seems to entail a host of extraintestinal (not related to the gut) symptoms that CD lacks.

Wheat allergy is your run-of-the-mill allergy, but rather misleadingly-named. Like other allergies, it can manifest as a food- or contact-allergy. Unlike other allergies, it can be caused by a range of compounds (rather than a particular allergen) contained in wheat. The European Center for Allergy Research Foundation (ECARF) states that “wheat allergy generally appears in infancy,” noting that roughly 0.3% of European children under the age of 5 and around 0.1% of all Europeans are allergic to wheat, making it a relatively rare condition.

Dermatitis herpetiformis (DH), or Duhring-Brocq disease, is a tell-tale sign of celiac disease, although the exact mechanism by which one causes the other remains unknown. The condition is a skin inflammation characterized by chronic rashes on the skin with red, liquid-filled blisters. They’re also very itchy. Estimates of DH prevalence range from 10 in 100,000 to around 80 in 10,000 individuals.

Gluten ataxia is a proposed condition. It’s basically gluten-induced ataxia, a condition characterized by dysfunctions in the central nervous system leading to loss of voluntary control or coordination over muscle movements. Gluten ataxia “usually presents with gait and lower limb ataxia” and may account for “15% amongst all [cases of] ataxias and 40% of all idiopathic sporadic ataxias,” according to a study published in 2015.

It’s important to note that there are several varieties of gluten intolerance going forward. Each has its own particularities of symptoms. However, there are some general symptoms that are indicative of such disorders.

Symptoms of gluten intolerance

Abdominal pain.

Most of them have to do with your belly. But not all of them.
Image credits Darko Djurin.

Abdominal pain after ingesting gluten — from grains and derived products such as flours, bread, baked goods, or beer — is the most common symptom of gluten intolerance at large. Up to 83% of those with gluten intolerance experience abdominal pain and discomfort after eating gluten.

Abdominal bloating is a close second. It’s a sensation of ‘swollenness’ or ‘fullness’ in one’s belly, caused by the release of gases in the gut. Generally uncomfortable, abdominal bloating can become painful and/or cause shortness of breath. Around 87% of people suspected to have NCGS experience bloating, but a majority of CD patients also report this symptom.

Bowel inflammation after consuming gluten is a common symptom of celiac disease. Damage of the gut lining causes inflammation resulting in significant digestive discomfort. In the long run, it can also lead to poor nutrient absorption.

Over 50% of gluten-sensitive individuals (both CD and NCGS) regularly experience digestive symptoms such as diarrhea, while about 25% experience constipation. Patients also report alternating between the two states. Celiac disease patients may also experience pale and foul-smelling feces (due to nutrients left over in the stool).

Tiredness after consuming gluten can also be a symptom. This is a bit trickier to diagnose, as life by itself tends to be quite tiresome. However, if you regularly (or constantly) feel fatigue and tiredness, especially after eating foods that contain gluten, it could be indicative of underlying gluten intolerance. Around 60% to 82% of gluten-intolerant individuals commonly experience tiredness and fatigue. Gluten intolerance can also cause iron-deficiency anemia, which in turn will make you feel tired and spent overall.

Dermatitis herpetiformis, as we’ve seen above, is a pretty dead giveaway for celiac disease. Other skin conditions — psoriasis, alopecia areata, and chronic urticaria — have also shown improvement under gluten-free diets, which suggests a link between them and gluten intolerance.

Gluten intolerance may also predispose individuals to depression and anxiety, especially those suffering from CD. While the mechanism underlying this link remains unknown, it has been proposed that changes in gut flora and exorphins formed during gluten digestion may interfere with serotonin levels in the brain. It also seems that switching to a gluten-free diet makes some patients “feel better” even if their gastrointestinal symptoms persist; all of which suggests a link between the two.

What to do about it

Brad and grains.

TL;DR don’t put these things in your mouth.
Image credits National Cancer Institute / National Institutes of Health.

The best course of action is to go talk to a doctor. But there are some preventive measures you can take if you think you’re suffering from gluten intolerance.

Unsurprisingly, you should avoid items that contain gluten — wheat, barley, malt, rye, and their derived products (brewer’s yeast can also contain gluten, for example). Some common foods and drinks that contain gluten include:

  • pasta, noodles
  • bread, pastries, baked goods such as crackers, biscuits, and cakes
  • breakfast cereals
  • pancakes, waffles, crepes
  • many sauces and gravies use flour-derived gluten as thickening agents
  • beers, malt beverages
  • potatoes, maize, and rice can also become contaminated with gluten in facilities that also process gluten-rich grains

Gluten-free varieties of such items are commercially available, although they tend to be more pricey. So it’s possible to enjoy them without worrying about gluten. But, as a rule of thumb, if you suspect a food item contains or has been in contact with wheat, barley, rye, malt, or products derived from those (and you believe you might be suffering from gluten intolerance), don’t eat it.

Now, I think it’s important to note that there’s also somewhat of a witch hunt among fad diets regarding gluten. Many such diets suggest gluten itself is bad for your health even if you’re not gluten-intolerant. There’s no credible scientific evidence for such claims that I could find, so I’m comfortable calling it a myth. Another part of the issue is that the symptoms of gluten intolerance are widespread and can have a lot of different potential causes — which makes gluten intolerance easy to misdiagnose.

All in all, if you believe you might be suffering from gluten intolerance, the best course of action is to go talk to a doctor.

On oats

In response to numerous queries concerning the use of oats in various products, the North American Society for the Study of Celiac Disease (NASSCD) released a statement saying that “the use of oats uncontaminated by wheat, barley or rye by individuals with celiac disease and dermatitis herpetiformis in North America has been endorsed by most experts.” However, they also note that “regular (commodity) oats in North America are likely to be contaminated with wheat and barley,” and recommend consulting a doctor or dietitian before including oats in gluten-free diets, as well as monitoring after inclusion.

There is some evidence that avenin, an oat protein similar in form and function to gluten, “can activate gluten-reactive T cells”, the Celiac Disease Foundation reports citing a 2015 study. A different study, published in 2017, reported that avenin “can cause small bowel mucosal damage in some people with coeliac disease.” While the first paper concludes that “low-level oats consumption may be insufficient for clinical relapse in CD patients,” the second one does not recommend including this cereal in gluten-free diets.

It has to be noted, however, that the second study was performed in Australia, and differences in labeling requirements may confuse results to an extent. The NASSCD, for example, specifies that “oats used in labeled gluten-free foods may now include mechanically/optically-sorted oats, a process which separates oats from wheat, barley and rye by color, size, and shape. These methods are used to produce “clean” gluten-free oats.” The first study also suggests that certain types of oats may induce CD symptoms in patients while others do not.

“Inclusion of oats in a gluten-free diet might be valuable due to their nutritional and health benefits, and several countries currently permit oats to be included as an ingredient in such diets,” it explains.

“However, it is extremely important to remember that in vitro studies have shown that the immunogenicity of oats varies depending on the cultivar used. Future clinical studies should be directed to the development of clinical trials with varieties previously identified as safe by reliable in vitro methods”

If you’re intolerant to gluten, play it safe. Look for the “gluten-free” label, or talk to a doctor to decide if oats are right for you.

Wheat.

What is gluten and why some people have gluten intolerance

“Gluten” is an umbrella term used to denote the mix of storage protein compounds found in all species and hybrids of wheat and its related grains (barley, rye, etc). Not a single substance but rather a mixture of various kinds of protein, gluten is, simply put, the way these cereals store building materials for the future.

Wheat.

*gluten intensifies*
Image credits Hans Braxmeier.

Owing to proteins’ tendency to bunch up or string together, gluten lends elasticity and texture to baked goods, making them either chewy or crunchy — “gluten” is actually the Latin word for “glue”. It’s also the object of many a fad diet and legitimate dietary concerns (primarily in the shape of allergies or intolerances), and a cool compound to use in making DIY playdough.

What is gluten made of

So right off the bat, gluten doesn’t have a set chemical structure. Its composition varies depending on the species in question and the exact percentages very likely differ from individual to individual. But in a general sense, gluten is a mixture of prolamins and glutelins.

Prolamins are a family of storage proteins used to stockpile (mainly) proline and glutamine, two amino acids which underpin protein synthesis for plants. Each crop produces and stores a different brand of prolamin — gliadin in wheat, hordein for barley, secalin in rye, zein in corn, kafirin in sorghum, and avenin (minor protein) in oats. Glutelins do basically the same thing as prolamins in chemically-different combinations and shapes. They’re rich in amino acids, particularly glutenin (wheat), though to a lesser overall degree than prolamins.

Proline&Glutamine.

The two amino acids gluten mainly stores.

All plants use protein stores of one kind or another, mostly concentrated in fruits in the case of endosperms, earmarked to supply budding plants during germination. The term gluten is sometimes extended to these stores as well (especially for corn or rice as they’re also cereals) but true gluten (with prolamins and glutelins) is only found in wheat, its related grains, and their species and hybrids. Some other gluten-free grains you’re likely to bump or bite into are quinoa, amaranth, and oats — although this last one is usually not recommended by dietitians, as it’s usually processed through the same channels as wheat-related grains, which can contaminate it with gluten.

Why gluten is good

Proline is considered to be a non-essential amino acid in the human body (the need can be covered by internal synthesis), while glutamine plays a non-essential/conditionally essential role (it is usually supplied by the body’s own synthesis processes, but must be supplemented by diet in certain stressful conditions). Glutamine has the distinction of being the most abundant free amino acid in the bloodstream.

So while they do have nutritional value, for the most part, our bodies don’t really need these amino acids. But gluten plays a central part in how we process and then consume grains. It accounts for the lion’s share of proteins in bread — anywhere between 75 to 80% — so to understand what it does, let’s take a quick look at how these behave.

Bread.

Those stretch-like marks are made by gluten holding the dough together during yeast fermentation.
Image credits Lebensmittelfotos.

Proteins are essentially long chains of amino acids strewn together and folded into certain shapes. They do all sorts of stuff in living bodies, such as pumping compounds in and out of cells or moving things around. But the thing we’re interested in right now is that they are also the go-to compounds when mechanical resilience and stiffness are required. Your nails are so hard compared to your skin because they’re rich in keratin. Your nose never breaks because elastin strands hold the cartilage together, just like the iron rods do in reinforced concrete. Cells keep their shape because tiny filaments of protein run from wall to wall and prop them up.

And that’s what gluten does in pretty much any foodstuff made from flour. By kneading it with water, bakers “weave” gluten into long elastic strands which act similarly to those of a polymer. These strands are made up of glutenin molecules which criss-cross into a microscopic net-like pattern along with gliadin (wheat glutenin) molecules, making the dough hold together, feel a bit rubbery, and stretchable. Heat treatment such as baking or boiling breaks the folding in gluten and makes it coagulate, which, along with starch, gives bread its mechanical properties. Gluten has also been identified as playing a part in the staling of bread, likely by binding atmospheric water molecules.

To get an idea of the physical properties of gluten and how it ties food together, you can play around with a lump of pure gluten. It’s quite fun — keep your hands clean and (most of) you can eat it afterward, too. If you don’t have any lying around, tofu is a similar product (soy/plant proteins but with a higher % of fat mixed in) which is more widely available.

What is gluten intolerance

Now, my reaction to hearing about a new fad diet is a wide smile and a knowing, paternal chuckle. And a big part of the demand for gluten-free products comes down to just that — a fad. To each his own (wallet) but, considering a number of foodstuffs that have gluten and their nutritional value, going gluten-free without any medical reason isn’t the best of ideas as it could end up making your diet way worse overall.

At least some people have a sense of humor about it.
Image credits William Murphy / Flickr.

That being said, some people who are gluten-sensitive or gluten-intolerant can’t eat gluten. There are several gluten-related disorders: celiac disease (CD) is the most common form of intolerance, then there’s the still-debated-on non-celiac gluten sensitivity (NCGS), and a slew of other nasty reactions from dermatitis herpetiformis and irritable bowel syndrome (IBS) to gluten ataxia and wheat allergy. People suffering from CD see their bodies produce an abnormal immune response when digesting gluten, making their digestive tract unable to absorb nutrients. About 18 million Americans have gluten sensitivity, according to the National Foundation for Celiac Awareness. Those with NCGS exhibit many of the same symptoms, due to poor digestion or a placebo effect, still under debate. So why does this happen?

The first thing you have to keep in mind is that while humans are omnivores, our bodies just aren’t geared to eating absolutely everything out there — but we’re very good at adapting. Certain populations overcome diet limitations over time through contact with traditional types of food.

For example, Western society as a whole is much less lactose intolerant than the rest of, well, mammals, since in nature milk is reliably on the menu only before weaning — after that, it’s highly unlikely to pop up, so mammalian bodies don’t maintain a stock of lactase because it doesn’t make economic sense for them to do so. But most westerners today have acquired lactose resistance through (relatively few) generations of natural selection for the ability to eat dairy, as milk was an important source of nutrients here. Writing in the New York time on this subject, Moises Velasquez-Manoff said:

“Few Scandinavian hunter-gatherers living 5,400 years ago had lactase persistence genes, for example. Today, most Scandinavians do.”

The “we’re not yet adapted to it” approach has a lot of support, and there may be some limited validity to that point of view in certain cases. We know of grain consumption even before agriculture, albeit on a reduced scale. It’s also likely that those cereals were poorer in gluten or might not have employed it all together (such as is the case with wild oats), meaning there was no reason to adapt to eating a lot of grains by that time. There is evidence tying CD to genetic factors. However, I’d say that adaptation similar to the one above led to a greater digestibility of gluten and likely worked up a natural tolerance for the majority of humans — else people wouldn’t have eaten it for like 23,000 years.

One other factor cited to play a hand in gluten intolerance is that selective breeding of wheat and related crops up to modern times led to increasing levels of ATIs (-α-amylase/trypsin inhibitors), which the plants use to fight off insects but also interfere with the digestive tract’s processing of gluten, and our bodies are still catching up to that. But research doesn’t point to any increase in ATIs.

One final factor may be more modern — after the transition to agriculture, the genes which cause autoimmune disorders may have provided an evolutionary advantage by keeping people extra-safe in the crowded, pathogen-rich environments of early settlements. And we’re seeing an overall increase in autoimmune disorders of every kind recently as more of the slack is taken away from our immune systems by drugs, making it liable to react out of proportion to perceived threats.

The bottom line is that we don’t really know where gluten intolerance stems from yet.

As for the other disorders, their causes vary quite a lot and may not even be understood or still debated in some cases. If you think you may have a form of gluten sensibility, speaking to a physician is your best way of getting more information.

Cool stuff gluten can do for you

You can still have some fun with gluten, even if you can’t eat it. Candia on Instructables has a nice guide set up so you can make some at home. The cream of tartar will make the dough more elastic, but even if you take it our of the mix the gluten is strong enough to keep the play-dough in one piece no matter how you stretch it. It’s basically dough so you don’t have to worry about the kids (or yourself) sneaking a bite out of it — but be mindful of intolerance.

If you’d rather feel like gluing your kids to the wall (I don’t judge), Wheatglue can come in handy. It’s as easy as mixing flour and water, as Instructabler theRIAA shows. It’s one of the oldest glues ever, used since antiquity to bind books and in the more modern art of plastering posters. Plus, it’s biodegradable so the little ones will come off on their own after some time.

This is not chicken — seriously. It’s seitan, which is basically gluten. The broccoli is just broccoli. Image credits: John / Flickr.

You can use gluten as an alternative to tofu (seitan) and will likely appreciate its more robust texture and stronger aroma compared to the subtle soy product. And as a bonus for vegetarians, you’ll finally have a go-to answer for when people ask where you get your protein from. It even looks a lot like meat, and it’s much healthier than tofu.

So is gluten right for you? Well, statistically speaking, probably yes.