There is an unbelievable amount of confusing information about gluten on the internet. The biggest misunderstanding about gluten is that only some people digest it poorly. The truth is that, in fact, all humans digest gluten poorly, and only some people demonstrate symptoms. Why does this difference matter? Let me explain.
First, some background information: gluten is a protein found in specific grains (wheat, barley, spelt and rye). It contains the two proteins gliadin and glutenin. Gliadin is the component of gluten that causes us the most trouble, and actually exists in four forms (epitopes): alpha, beta, gamma, and omega. (1)
When wheat is consumed, it is broken down by enzymes called transglutaminases in the intestinal tract (2, 3). Gliadin and glutenin are two of the resulting proteins, and they are difficult for the body to fully digest (2, 3). The intestinal tract is also home of ~70% of the body’s immune system (4). Unfortunately, in some individuals, the immune system perceives gliadin as a foreign invader, similar to bacteria (2, 3). It launches responses that can be classified in three possible ways: Celiac Disease (autoimmune, IgA mediated), wheat allergy (IgE mediated), or Non-Celiac Gluten Sensitivity (NCGS).
In the case of Celiac Disease, the body specifically attacks the alpha epitope of gliadin and the type of transglutaminase that binds it (tTG-2). This autoimmune response results in damage to the gut lining and painful gastrointestinal symptoms. It also often causes symptoms in other parts of the body, which I will describe in more detail below. Blood tests for Celiac specifically look for antibodies against alpha-gliadin and tTG-2, and diagnosis is also often confirmed by biopsy (confirmation of damaged tissue).
However, research has shown that people also react to other components of wheat and gluten, such as the other three forms of gliadin (beta, gamma, and omega), and glutenin (5, 6). These reactions are collectively referred to as Non-Celiac Gluten Sensitivity (NCGS).
NCGS is characterized by gastrointestinal symptoms (diarrhea, abdominal pain, bloating, and/or flatulence) OR other symptoms (fatigue, brain fog, headache) occurring after gluten ingestion, which improve after eliminating gluten (7, 8). Unfortunately, no conclusive test for NCGS yet exists and, thus, it is defined by the improvement of symptoms when gluten is removed for a period of time (7).
Of the three responses, NCGS, is the largest source of confusion on the topic of gluten. NCGS is now believed to exist in 6-10% of the population (9). Recently a randomized controlled trial (the gold standard of scientific research) showed that subjects who believed they were gluten sensitive (but without Celiac or wheat allergy) experienced a significant increase in symptoms when consuming gluten versus placebo (10). Thus, there is now strong scientific evidence proving the existence of NCGS.
Aside from the autoimmune response to tTG-2 characterized by Celiac Disease, gluten consumption can also stimulate an autoimmune response to additional types of transglutaminase, such as type 3 (primarily in the skin), and type 6 (primarily in the brain) (11, 12). This fact is believed to be the reason why, in addition to it's link to irritable bowel syndrome (13), NCGS has been linked by peer-reviewed research to many conditions not characterized by digestive symptoms. These include dermatitis (14), multiple sclerosis (15), fibromyalgia (16), depression (17), ADHD (18), type-1 diabetes (19), schizophrenia (20), endometriosis (21), autism (22), ataxia (23), Hashimoto's thyroiditis (hypothyroidism) (24), and neurological disorders including myopathy and peripheral neuropathy (25).
Now that you've learned the possible effects of gluten, you may be wondering what the chances are that YOU are effected in one of these ways. The portion of the population with Celiac Disease is estimated around 1%, and the portion with NCGS is estimated at 6-10% (26, 27). Further, researchers have shown the incidence of Celiac Disease to be increasing at alarming rates:
- 5-fold in the US since 1974 (28)
- 5-fold in the US military between 1999 and 1998 (29)
- 2-fold in Finland in the past two decades (30)
- 4 fold in the UK over the past two decades (31)
- 3-fold in the Netherlands over 15 years (32)
- 6.4 fold (pediatric) in Scotland over the past 20 years (33)
The increase can not alone be explained by increased detection of the disease (34 35). Rather, it is largely believed to be related to changes the microbiome and impaired mucosal barrier function (36, 37). Some have theorized that modern wheat (as opposed to ancient versions) are to blame, because modern wheat is more gluten-dense and is prepared without sprouting and fermentation. However, leading gluten researcher Dr. Fasano cites changes in the microbiome, rather than changes in wheat, to be the main cause of the increase in Celiac Disease (36).
This combined body of information has led to the common recommendation of eliminating gluten for a period of time and then avoiding it forever if there is a positive response during the elimination period. However, there are several problems with this suggestion.
The problems with simply cutting out gluten
1. Possible reaction to grain components other than gluten
A recent study showed that in some IBS patients who believed they were gluten sensitive, the true cause of their symptoms was the type of carbohydrate in wheat (a FODMAP), rather than the gluten (38, 39). Thus, a positive response to a gluten-free diet may, in fact, be due to an intolerance to wheat itself and not gluten. These individuals may falsely get the idea that they should be gluten free when, in fact, they need to avoid specific types of FODMAP carbohydrates.
2. There’s more to it than how you feel
In other words, if you don’t get negative symptoms from gluten, that doesn’t mean it’s not causing you harm. Let me explain.
As described above, gluten is poorly digested by everyone (2, 3). Specifically, gluten stimulates a protein called zonulin to increase gut permeability. This causes what is commonly known as "leaky gut".
Various factors can effect the body’s response to this. In the case of an autoimmune response, the symptoms may not appear as gastrointestinal. Consider that among people with Celiac disease, 44% have non-gastrointestinal symptoms and approximately 33% don't experience any symptoms - they have no physical indication that their body is attacking itself (40). This 'silent Celiac disease' does not mean there is no effect - all Celiac patients are at increased risk for cancer, type-1 diabetes, Hashimoto's hypothyroidism, osteoporosis, osteomalacia, anemia, ataxia, neurological disease, and hepatitis (40, 41). Further, the length of time exposed to gluten increases the risk of autoimmune disease (40).
3. Gluten-free products are not necessarily better for you
Now that going "gluten-free" is so popular, there are a lot of processed, gluten-free foods available for purchase. I've seen gluten-free cookies, cake, and even "funfetti" mixes. Processed foods really aren't doing you any favors nutritionally, whether they are gluten-free or not. If you chose to avoid gluten, I suggest replacing those calories with nutrient-dense, ancestral choices. Carbohydrate examples of that include starchy vegetables, fruit, and (if well-tolerated), some forms of rice.
4. High pesticide use
Although genetically-modified wheat is not approved for use in the United States, pesticide use on wheat is still high. For example, wheat crops in California were treated with 386,000 pounds of pesticides in 2012 (42). Pesticides have been shown to pose serious risks to human health, including a significant risk of cancer and neurotoxicity (43, 44, 45). Of course, a gluten-free diet does not eliminate all pesticides from the diet, but replacing wheat with organic versions of other carbohydrate sources (i.e. starchy vegetables and fruit) does reduce exposure.
So, what does all this information mean for you?
1. Eat REAL FOOD
As described above, gluten researchers attribute the increased incidence of gluten intolerance and Celiac disease to changes in the microbiome and impaired intestinal mucosa barrier function (36, 37). Fortunately, nutrition has a significant effect on these factors. Thus, one step in reducing the risk of gluten consumption is optimizing your gut health by eating the ancestral foods your body was designed to digest.
2. Determine if you have wheat and/or gluten intolerance
A gluten elimination trial can help you get answers, but it isn't the end of the story. To complete a gluten elimination trial, completely cut it from your diet for 60 days, then reintroduce it. If you feel great off gluten then have symptoms after reintroducing it, you know there's something in gluten-containing grains that you don't tolerate. If this is the case, you can try eating barley to see if the gluten itself is your problem, or if it is actually another component of wheat such as FODMAPs. This is because barley contains gluten but is low-FODMAP. If you feel the same eating wheat or not, you may be fairly gluten tolerant. Another option is to work with a practitioner to test for bio-markers of wheat and gluten intolerance.
3. Make your final decision
What should you do if you try eliminating gluten and feel the same either way? This is where much of the controversy lies. I encourage you to consider the risk of 'silent Celiac disease', and the fact that length of exposure increases risk of autoimmune response to gluten. I also encourage you to consider the implications of the pesticides used to grow wheat. Also consider that there is no nutritional need for gluten or wheat - it is, in fact, very nutrient-poor (46). Overall diet quality is actually significantly greater if gluten-containing foods are replaced with nutrient-dense, whole foods.
After considering this information, you may weigh the risks and decide to continue eating gluten, in which case I encourage you to still focus on whole, real food rather than foods containing refined wheat flours.
The burden of wheat and gluten intolerance in our society is now becoming more clear. You may see exaggerations that gluten is the cause of 'all disease', but the truth is that it is a significant contributor for a portion of the population. The choice to eliminate gluten is an individual one, based on many factors. For many, the idea of eliminating gluten or following an ancestral diet is overwhelming. You are welcome to contact me or check out the plans I offer to help you on your journey.