Gluten and Psoriasis: Part 1

Does Gluten Play a Role in the Disease Process of Psoriasis?

Does eating gluten-containing foods play a role in your psoriasis? Have you tried cutting gluten from your diet? Did you experience an improvement in your skin, joints, mood, or other areas of your body? Many people with psoriasis have reported an improvement in their health once eliminating gluten. Medical scientists are currently working to better understand the role of gluten in psoriasis and other autoimmune diseases and recent research is shedding light on the impact that gluten can have on these various conditions.  

Research estimates that 25 percent of patients with psoriasis respond favorably to a gluten-free diet. For a small percentage, removing gluten from their diet results in a complete clearing and remission of their disease. Others see a mild improvement in their skin, while some notice no appreciable difference. How can we explain this varied response? There are several avenues of research that have yet to converge, but that do provide valuable insights.

What is Gluten?

First, you might be asking yourself, what is gluten? Gluten refers to the gliadin and glutenin proteins found in wheat, as well as many other cereal grains (including wheat varieties like spelt, kamut, farro and durum, plus products like bulgar, semolina, barley, rye, triticale and some oats.) Gluten has a special elastic and expansive quality that, when the dough rises and bakes, it expands allowing for air to enter into the dough and ultimately resulting in the chewy, fluffy bread that we all love so much.

So why give that up?! One third of Americans state that they are trying to avoid gluten in their diet. This shift has led many doctors to conclude that following a gluten-free diet is simply a social trend (excluding the 1-2% of those with diagnosed celiac disease). However, a thoughtful and careful review of the literature, in addition to listening to individual patient stories, confirms that there is real physiology behind the numbers.

Why is Gluten Potentially Harmful?

As important as gluten is to bread, it can be as equally harmful to our bodies. Gluten is very hard to digest and often remains in the intestines for prolonged periods. Most people can consume gluten without experiencing any adverse effects. However, this is not the case for all of us. Gluten-related diseases and conditions include celiac disease, dermatitis herpetiformis, gluten ataxia, non-celiac gluten sensitivity, cutaneous gluten syndrome, and an emerging body of evidence suggests gluten-associated autoimmune disease. That’s a pretty impressive list for a single food protein! This alone should make anyone pause when it comes to gluten and their health.

But in which category do those with psoriasis fit? Again, the answer is not yet clear and it may well be that there are a variety of ways that gluten can affect those with psoriasis. The genetics of psoriasis are complex, involving over 1,000 genes and, therefore, not everyone with psoriasis has the same genetic variants. This partially explains the different responses to various psoriasis triggers, including gluten.

What’s the Relationship Between Gluten and Psoriasis?

Having psoriasis significantly increases your risk for celiac disease. Psoriasis patients diagnosed with celiac disease generally show improvement or clearing of skin lesions once removing gluten from their diet. This suggests a causal relationship between the two diseases that may be a result of shared genes, as well as other physiologic conditions. But, this explains a very narrow percentage of those with psoriasis that show improvement upon adopting a gluten-free diet.

• There is also a subset of patients with psoriasis who do not have celiac disease, but do have anti-gliadin antibodies. These patients also show significant improvement of their skin upon adopting a gluten-free diet. This has led researchers to suggest that all psoriasis patients with gastrointestinal symptoms (bloating, abdominal pain, flatulence, diarrhea, etc.) be screened for celiac disease, including testing for anti-gliadin antibodies. The recommendation following a positive screen for either celiac disease or anti-gliadin antibodies alone is to adopt a gluten-free diet.

• There are also cases of improved skin lesions while on a gluten-free diet with neither overt celiac disease or gluten-associated antibodies. The prominent Harvard researcher, Dr. Alessio Fasano, and his team have produced a revealing set of studies related to gluten and autoimmune disease. Dr. Fasano’s initial work on celiac disease has been expanded to include an exploration on how gluten may impact or initiate the disease process in type 1 diabetes, multiple sclerosis, and other autoimmune diseases. This body of research does not include studies specifically on psoriasis, however Fasano and his team suspect that the pathophysiology is similar for many, if not all autoimmune diseases. Given that we know a significant percentage of patients with psoriasis improve following a gluten-free diet, it is reasonable to explore this concept as it may relate to psoriasis.

How Does Gluten Impact the Body?

Dr. Fasano’s work focuses on the intestinal wall and its ability to dynamically increase and decrease it’s permeability, or degree of “leakiness”. The cells lining the gastrointestinal tract form a wall, or a barrier, between the contents of your gut and the inside of your body. The cells that form this barrier are connected by tight junctions that can open and close in response to various signals. The opening and closing of the tight junctions thereby alters the intestinal permeability. Having an intestinal wall that is permeable serves many functions including allowing the immune system to quickly sample what is coming through your gastrointestinal tract and respond to pathogenic bacteria or other threats.

However, there are triggers that can result in the tight junctions staying open for too long and causing the gut wall to be abnormally permeable or “leaky”. Gluten triggers the opening of tight junctions in all people, but in some people it causes an abnormally prolonged opening. This allows for undigested proteins, gluten itself and other gut contents, to move from the gut to the inside of the body. Gluten, as well as other wheat proteins, is also a strong stimulator of the immune system and can trigger a chronic inflammatory response. Research suggests that this process may be an initiating and/or perpetuating factor in various autoimmune diseases.

An increased intestinal permeability has been shown to occur in those with psoriasis, gluten sensitivity and many autoimmune diseases.  This, and the fact that a significant percentage of people with psoriasis improve on a gluten-free diet, makes gluten a very suspicious agent to consider when it comes to psoriasis.  

What if Eliminating Gluten Doesn’t Help?

So, what about people who don’t show improvement upon removing gluten from their diet? Is it possible that other factors in the disease process are overwhelming any positive effect?  Ibuprofen (and other medications in this drug class) are also strong stimulators of the opening of tight junctions and lead to increased intestinal permeability. Stress plays a clear role in many with psoriasis and may be a primary mediator. There are also many other triggers of the disease process such as a sedentary lifestyle, alcohol, smoking, trauma, poor quality foods, chemicals, and the list goes on. Removing as many triggers as possible, including gluten, provides your best hope for freedom from disease.

So What?

We have a significant body of research with compelling insights, but an incomplete explanation for how gluten specifically relates to those with psoriasis. At this point, you are your best doctor when it comes to determining how gluten may be affecting your health.

However, from what we do know at this point, if you have psoriasis you should consider exploring how gluten may be impacting your health.  And, I can tell you first-hand, that after enough time passes it really does become very easy to pass on the bread basket!

 

References

Abenavoli, L., et. al.  (2007).  Celiac disease and skin: Psoriasis association.  World J Gastroenterol, 13(14), 2138-2139.

Balakireva, A. & Zamyatnin, A.  (2016).  Properties of Gluten Intolerance: Gluten Structure, Evolution, Pathogenicity and Detoxification Capabilities.  Nutrients, 8, 644.

Bhatia, B., et. al. (2014).  Diet and Psoriasis: Part 2. Celiac Disease and Role of a Gluten- Free Diet.  J Am Acad Dermatol, 71(2): 350–358.

Bonciolini, V., et. al.  (2015).  Cutaneous Manifestations of Non-Celiac Gluten Sensitivity: Clinical Histological and Immunopathological Features.  Nutrients, 7, 7798-7805.

De Bastiani, R, et al.  (2015).  Association between Coeliac Disease and Psoriasis: Italian Primary Care Multicentre Study.  Dermatology, 230, 156–160.

Fasano, A.  (2011).  Zonulin and Its Regulation of Intestinal Barrier Function: The Biological Door to Inflammation, Autoimmunity, and Cancer.  Physiol Rev, 91, 151–175.

Hollon, J. et. al. (2015).  Effect of Gliadin on Permeability of Intestinal Biopsy Explants from Celiac Disease Patients and Patients with Non-Celiac Gluten Sensitivity.  Nutrients, 7, 1565-1576.

Humbert, P., et. al.  (1991).  Intestinal Permeability in Patients with Psoriasis.  Journal of Dermatologic Science, 2, 324-326.

Mu, Q., et. al.  (2017).  Leaky Gut As a Danger Signal for Autoimmune Diseases.  Frontiers in Immunology, 8, Article 598.

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My World Psoriasis Day Resolution!

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Friday, March 16th, 2018

Gluten & Psoriasis: Part 2