Gluten pseudoscience is based on a 'grain' of truth
Gluten only needs to be avoided with specific health conditions
Last week, I wrote about autoimmune diets, rigid elimination diets that claim to alleviate symptoms of a wide and diverse array of autoimmune conditions that all have unrelated pathology. With many pseudoscience claims, they are often based on ‘grains’ of truth: in the case of the autoimmune and anti-inflammatory diet, those are two-fold:
Inflammation is a hallmark of pathology of autoimmune disorders as a result of inappropriate immune responses directed towards the self. The falsehood lies in the fact that these diets claim to eliminate foods that “cause inflammation” which is not based upon credible science.
There is an autoimmune disorder that does require elimination of specific foods: Celiac disease. This autoimmune disorder occurs as a result of an inappropriate immune response in the intestine against gluten proteins, and management involves avoiding foods containing gluten. The falsehood lies in extrapolating that to autoimmune disorders that are not Celiac disease and recommending people avoid more than just gluten.
Gluten has also become the target of pseudoscience in the wellness industry.
Gluten is a buzzword among wellness influencers, ‘nutrition coaches’, and non-physician practitioners. Almost every product in grocery stores now boasts a gluten-free counterpart. But what sparked the widespread concern about gluten? In short, pseudoscience (do you sense a trend?) - where a legitimate medical condition related to gluten has been wildly extrapolated to make unfounded claims. Before we dig into that, let’s start with the basics:
Gluten is a structural protein found in cereal grains
Commonly associated with wheat, gluten in a medical sense extends to a blend of prolamin and glutelin proteins present in grains. These include wheat varieties like durum, spelt, and khorasan, as well as barley, rye, and some oats. In bread wheat, gluten makes up 75–85% of total protein content.
Gluten is not in grains such as amaranth, arrowroot, buckwheat, corn, rice, flax, quinoa, soy, sorghum, tapioca, teff, or other foods like potatoes, legumes, beans, seeds, nuts, fruits, and vegetables.
Gluten is actually produced when two smaller proteins – gliadin and glutenin – bind to each other. This requires the presence of water, which hydrates gliadins and glutenins. As they are hydrated, and mixed (during dough mixing), the gluten proteins form strong inter- and intramolecular bonds through disulfide bridges, van Der Waals attraction, and hydrogen bonding. This mechanical mixing facilitates interactions between the different amino acids in the proteins and alters the structural shape of the molecules. This also gives dough viscoelasticity (the springy and bouncy characteristics) and imparts structure (the crumbs/pockets) to baked bread.
The more a dough is mixed, the more structures are created and the more gluten is formed. That’s one reason why pastries often have less gluten than sandwich breads: they are not mixed and kneaded for the same duration, so less gluten forms.
Why the hype around this one little protein?
Gluten has gained attention in pop culture because it is implicated in very specific medical conditions, specifically, Celiac disease (and far less commonly, gluten ataxia).
As a result, pseudoscience has dug its claws into gluten.
Celiac disease is an immune reaction in the small intestine triggered by gluten. Gluten ataxia is an extremely rare ataxia that appears to be mediated by autoimmune reactions to gluten.
But if you listened to social media, celebrities, wellness influencers, and naturopaths, you’d think that gluten is causing nearly every potential medical issue:
Brain fog, depression, and anxiety
Autism, Alzheimer’s, and other neurodegenerative disorders
Non-Celiac autoimmune disorders: psoriasis, type 1 diabetes, rheumatoid arthritis, multiple sclerosis
Non-autoimmune inflammatory or musculoskeletal disorders including osteoarthritis
Bloating, gas, leaky gut syndrome
Chronic fatigue, adrenal fatigue
“toxicity” broadly
Weight gain, metabolism issues
If you listened to these folks, you’d be understandably concerned.
The good news? There is no evidence to support these claims.
Celiac disease is an inappropriate immune response to gluten
Celiac disease is a result of an inappropriate immune response to gluten, a protein found in wheat, barley, and rye. Instead of being viewed as benign and ignored by intestinal immune cells, gluten is mistakenly flagged as being a ‘foreign invader’. This leads to an inflammatory response in the small intestine, causing damage to intestinal epithelial cells and the villi, which help absorb nutrients during digestion. As a result, malabsorption can occur, especially among individuals with undiagnosed celiac.
Symptoms of Celiac disease include:
diarrhea
abdominal pain
bloating
weight loss
malnutrition
failure to thrive in children
Unmanaged celiac disease can lead to iron-deficiency anemia, osteoporosis, neurological disorders, and increased risk for some intestinal cancers. Many of these complications are a result of malnutrition risk associated with unmanaged celiac and the localized tissue damage that can occur in the intestine. Some individuals may present with dermatitis herpetiformis, a skin manifestation of Celiac. Celiac disease can co-occur with other autoimmune disorders such as type 1 diabetes and autoimmune thyroid disease.
There is a genetic contributor to developing celiac disease, but the pathology is multifactorial. Not everyone with certain gene characteristics go on to develop the condition. Diagnosis should always be undertaken with clinical immunologists, and it can involve medical history, food challenge, as well as intestinal biopsies and blood tests for antibodies that indicate self-reactivity (these are called autoantibodies). It cannot be diagnosed using at-home health tests.
Celiac disease has an estimated global prevalence of 0.5 to 1 percent. A meta-analysis revealed that the worldwide prevalence based on blood tests is around 1.4%, and 0.7% based on biopsy results, with variations across different regions and age groups. Diagnosis and management of celiac disease and related conditions revolve primarily around a gluten-free diet, and should always be overseen by clinical experts.
Separate from Celiac disease, wheat allergy also exists. However, wheat allergy is an IgE-mediated allergic reaction that is distinct from the response observed in Celiac disease, an autoimmune condition.
Wheat allergies are directed against a few different proteins found in wheat, with the most common offenders being albumins and globulins. Gliadins and glutenins can also lead to allergic responses. Wheat allergy compared to other food allergies is relatively uncommon, with global estimates ranging from 0.4 to 1% among children and adults. Symptoms of wheat allergy are similar to other food allergies and include swelling, hives, itching, and in more severe cases, anaphylaxis.
Some people also float the term 'non-celiac gluten sensitivity’ (NCGS). Symptoms like abdominal pain, bloating, and headaches are reported that do not present with damage to the small intestine tissues, which is a key pathological finding in celiac disease and differentiate this NCGS from Celiac disease. It is also important to note that these symptoms are not able to be reproduced when double-blind food challenges are conducted: when patients and researchers don’t know if the foods they’re consuming have gluten in them. As such, there is controversy around the legitimacy of this diagnosis, and it may be placebo or a non-gluten-related physiologic effect.
NCGS is not well-characterized, and there are no diagnostic tests to determine if this is truly related to gluten, another substance found in gluten-containing foods, or symptoms unrelated to food itself (i.e. gulping air when chewing, stress, etc).
This is not to say people aren’t reporting symptoms, but it is possible that this is an intolerance, whereby digestion of a substance is impacted usually as a result of insufficient levels of enzymes needed to digest the molecules (like lactose intolerance). To date, it is not clear whether these symptoms reported among these individuals relate to gluten or to something else in gluten-containing products (such as certain carbohydrates or other proteins like gliadin).
Do you need to avoid gluten if you have a different autoimmune condition?
The idea that avoiding gluten is beneficial for various autoimmune disorders or inflammatory conditions is largely a myth. In reality, a gluten-free diet is not a “wellness promoting” diet; it should only be undertaken if medically necessary.
There are no clinical data to suggest consuming gluten exacerbates other autoimmune disorders. Many people cite small or observational studies with regard to other autoimmune conditions, but these aren’t supported by large-scale and robust data. These are typically supported by anecdotal reports only.
Another potential confounder: small studies that suggest a potential link between gluten and autoimmune thyroid disorders, like Hashimoto's thyroiditis, fail to note that these individuals may co-present with celiac disease. In other words, celiac disease is the reason gluten elicits symptoms, not the thyroid condition.
While there's ongoing research into the potential role of gluten on various autoimmune disorders, current evidence does not support the necessity of a gluten-free diet for these conditions outside of celiac disease. Although some people may report symptom relief, there is a lack of robust scientific evidence to recommend a gluten-free diet for autoimmune conditions other than celiac disease. As always, dietary changes should be undertaken with medical guidance.
Does gluten cause inflammation when you eat it?
Inflammation is the body's immune response to various stimuli or insults, such as physical injuries, infections, post-exercise recovery, or even digestion. The immune system carefully balances inflammatory and anti-inflammatory processes, as excess in either direction can be detrimental. Unfortunately, many of these concepts and terms get misunderstood, misused, and misinterpreted by the wellness industry, scaring people about a completely normal and essential thing that happens all the time. You don’t want to ‘avoid inflammation’, because it is a necessary physiological response.
The reality is that our body's cellular processes, including those that produce inflammation, are part of normal physiological functions. The notion that all inflammation is detrimental is an oversimplification of the body's complex balance of inflammatory and anti-inflammatory processes. Anytime we eat ANYTHING, we create inflammation: digestion is a catabolic process, which means we release energy as we break large molecules into smaller ones. I discussed this in more detail in the autoimmune diet piece last week.
Our bodies take food and break it down into macromolecules, which are converted into usable energy through cellular respiration. This process involves converting carbohydrates, fats, and proteins into ATP (adenosine triphosphate), our cells' primary energy currency. Cellular respiration produces free radicals and reactive oxygen species (ROS), which are byproducts that are vital for certain physiological functions, but they also lead to transient inflammation.
The good news? Our bodies are excellent at regulating these processes. Inflammation, and gluten, have become buzzwords among the wellness industry that are often laced with unfounded claims.
Are there harms in avoiding gluten if you don’t need to?
There are potential risks associated with unnecessarily avoiding gluten-containing foods when not medically required. Avoiding gluten can lead to nutritional deficiencies. Gluten-containing grains are important sources of B vitamins, iron, and fiber. A gluten-free diet, if not properly managed, can result in lower intake of these nutrients.
Some studies suggest that a gluten-free diet in individuals without celiac disease or non-celiac gluten sensitivity might increase the risk of cardiovascular disease, due to the reduced consumption of whole grains which are known to be heart-healthy. Gluten-free diets can alter gut microbiota composition. This alteration might negatively impact gut health and immune function, as a diverse gut microbiota is crucial for maintaining overall health.
Gluten-free products are often more expensive than their gluten-containing counterparts. Additionally, adhering to a strict gluten-free diet can have social implications, potentially affecting quality of life and social interactions.
While a gluten-free diet is essential for individuals with celiac disease or non-celiac gluten sensitivity, its unnecessary adoption can lead to nutritional deficiencies, potential health risks, and socio-economic challenges. It's crucial for dietary changes, especially the exclusion of major food groups like gluten, to be undertaken under the guidance of healthcare professionals.
I heard that American wheat causes health issues, is that true?
We often encounter the belief that American wheat is of lower quality compared to its European counterpart, and as such, European breads are less problematic for digestion.
However, when actually assessing the prevalence of celiac disease, there's no disparity between the U.S. and Europe. The incidence of celiac disease is roughly the same in both regions, affecting about 1 in 133 people, or approximately 0.7% of the population, effectively challenging the notion that European wheat is inherently 'safer' or 'better'.
In the U.S., approximately 60% of wheat grown is hard red wheat, with soft wheat comprising about 23%. Conversely, in Europe, soft wheat varieties are more prevalent. Hard wheat has a higher protein concentration (which includes gluten) than soft wheat. Hard red wheat contains 13-16% protein, compared to soft wheat, with about 7.5-9% protein. While Europe grows less hard red wheat (due to climate), Europe imports around 1.1 million tons of American wheat annually, making American wheat ubiquitous across the European Union. In reality, there is very little difference in wheat types across these nations and use is dictated by product: hard red wheat is better for soft fluffy breads, whereas soft wheat is used more for pastries and cakes.
The perception that European wheat is inherently "better" or "safer" may be more placebo than reality. This aligns with broader misconceptions in discussions about food safety, including food colorings and GMOs, where perceptions don't match scientific evidence.
Unfortunately, gluten has been demonized by false claims perpetuated by the wellness industry.
Like everything, if you don’t have a legitimate medical reason to avoid gluten or gluten-containing products, then gluten is a perfectly health component of your overall diet.
Thanks for joining in the fight for science!
Thank you for supporting evidence-based science communication. With outbreaks of preventable diseases, refusal of evidence-based medical interventions, propagation of pseudoscience by prominent public “personalities”, it’s needed now more than ever.
Your local immunologist,
Andrea