Gluten is a protein composite found in wheat and related grains. It’s a composite of proteins glutenin and gliadin.


Gluten is found in wheat and related grains, including barley and rye. It’s the substance that makes bread dough sticky. And because it’s sticky, it’s also used as a binding agent in personal care products; for example, there can be gluten in your shampoo, toothpaste, and makeup.

Common gluten sources include:

  • Wheat
  • Barley
  • Rye
  • Spelt
  • Imitation meats

Exposure to most gluten comes from eating grains. However, many processed foods contain either wheat flour or gluten, and you may be exposed to gluten even from non-grain foods. has an extensive ‘unsafe foods list’.

Gluten and skin problems

A 2015 paper on skin manifestation of non-celiac gluten sensitivity called the skin and the gastrointestinal system as “two sides of the same coin.”

Nevertheless, we want to stress once again the importance of a close collaboration between gastroenterologists and dermatologists, because the gastrointestinal system and the skin may be considered more and more “two sides of the same coin”

Bonciolini, V., Bianchi, B., Del Bianco, E., Verdelli, A. & Caproni, M. Cutaneous Manifestations of Non-Celiac Gluten Sensitivity: Clinical Histological and Immunopathological Features. Nutrients 7,7798–7805 (2015).

In people with celiac disease, gluten causes obvious damage to the gut. And doctors have long known that people with celiac disease often also have skin problems. People with celiac disease have 150% to 300% higher risk of various skin diseases than the general population.

However, skin problems from gluten are not limited to people with celiac disease. People with so-called gluten sensitivity also often have skin problems. For example, an Italian study of 438 people with suspected gluten sensitivity showed that 29% complained of skin rash.

Likewise, a 2000 study on psoriasis patients found that 16% were sensitive to gluten. And 82% of the gluten sensitive psoriasis patients improved significantly after 3-months on a gluten-free diet.

There are also other studies that showed a gluten-free diet improved various skin diseases. I’m not going to go over all of them here. Mainly because none of them involved acne patients, and nobody has studied whether gluten is also linked to acne

My point is that gluten has been shown to cause skin problems, and you should treat it as a potential suspect.

I should also point out that not everyone with skin issues have gluten intolerance. In fact, most people with skin problems have no problems eating gluten, and cutting out gluten does absolutely nothing to their skin. But a certain percentage of people are sensitive to gluten, and for those people cutting gluten can solve the skin issues.

Common symptoms of gluten sensitivity

Gluten sensitivity can cause the following symptoms:

  • Gastrointestinal symptoms: abdominal pain, bloating, flatulence, diarrhea, or constipation
  • Skin problems: itching, rash, eczema, psoriasis
  • Fatigue and ‘failure to thrive’
  • “Foggy mind” and difficulties to concentrate
  • Limb and joint pain
  • Headaches

Why gluten causes health problems

Pioneering work by Dr. Alessio Fasano has shown how gliadin (gluten is a composite of proteins glutenin and gliadin) causes intestinal permeability.

The intestinal wall faces a serious challenge. On one hand it has to allow passage of nutrients and other beneficial substances. On the other hand, it has to keep out bacterial toxins and other harmful substances. To do this, the intestinal wall must be able to regulate its permeability. One way it achieves this is by opening and closing the gaps between the cells that make up the intestinal wall. In medical speak these gaps are called tight junctions.

Zonulin is a protein that regulates the tight junctions between intestinal cells.

Research by Dr. Fasano and colleagues showed that exposing intestinal cells to gliadin causes them to release zonulin and opens up the tight junctions – causing intestinal permeability.

These combined data demonstrate that Zot [zonulin] regulates TJ [tight junctions] in a rapid, reversible, and reproducible fashion.

Fasano, A. Zonulin and its regulation of intestinal barrier function: the biological door to inflammation, autoimmunity, and cancer. Physiol. Rev. 91, 151–75 (2011).

The link between zonulin and intestinal permeability is so robust that the levels of zonulin in the blood are used to detect intestinal permeability.

Here’s an easy way to visualize this. Think of the intestinal wall.. as.. well, a wall. Solid and impenetrable. The wall needs an opening so that the nutrients can pass through. We can think of these openings as doors. In this case, they are automatic doors. You can open the doors by touching a key card on the reader, and the doors close automatically after you pass through. In this analogy zonulin is the keycard that opens the doors.

Usually zonulin levels in the intestines are strictly regulated. For our analogy, we can imagine a receptionist at the lobby. In a healthy system, he checks everyone who comes in carefully and gives the keycards only to people with a proper security clearance.

But in celiac disease and other gluten problems, the receptionist is lazy. He’s sleeping at the backroom and left a box of keycards on the reception counter. So now everyone who comes in has a keycard. This is more or less what happens in celiac disease. Gliadin triggers a massive secretion of zonulin. The doors in the intestinal wall are constantly open.

In the gut health section I explained how intestinal permeability causes insulin resistance and systemic inflammation. In short, defective gut barrier allows improperly digested food proteins and bacterial toxins to escape, or leak, into the bloodstream.

Lipopolysaccharides (LPS) are toxic substances found in the outer membranes of harmful gut bacteria. In large quantities, they can cause septic shock, and chronic exposure to small quantities has been linked to diabetes, heart disease, and other chronic health problems.

To stress the point, zonulin has been linked to several health problems, among others:

  • An Indian study from 2014 showed that zonulin and LPS levels are linked to diabetes. The study showed that those with higher levels of LPS in the blood were 13 times more likely to develop type-2 diabetes.
  • A 2015 study on PCOS patients showed that women with PCOS have significantly higher levels of zonulin in the blood and that the higher the zonulin levels were, the more menstrual problems the women experienced.
  • A 2005 study linked zonulin to skin problems. The study showed that 87.5% of the dermatitis herpetiformis patients in the study had higher than normal blood zonulin levels, which were linked to increased intestinal permeability and inflammatory damage in the skin.
  • A 2012 study linked higher blood zonulin levels to elevated blood sugar, insulin, and inflammation levels.

How to know if you are gluten sensitive

There are two ways to know whether you are gluten sensitive.

  1. You can ask a doctor to be tested for anti-gliadin antibodies (AGA). However, I don’t recommend asking this test from naturopaths or other alternative health practitioners. You can have certain AGAs in the blood simply from eating gluten, and they don’t necessarily mean you are gluten sensitive.
  2. Elimination and re-challenge is the most reliable way to know if you are gluten sensitive. Eliminate gluten from your diet for at least three weeks, though some people say they required full two months without gluten to see improvements. After sufficient elimination period, eat something with gluten, for example, a meal with pasta and a few slices of bread. If this meal doesn’t trigger any negative symptoms in the next day or two, you most likely aren’t gluten sensitive.

Gluten vs. FODMAP sensitivity

FODMAPs are poorly absorbed sugars and carbohydrates that are rapidly fermented by gut bacteria and can trigger symptoms of irritable bowel syndrome. I covered them in more detail in the in-depth section.

Many people with gluten sensitivity may, in fact, have FODMAP sensitivity. It can be hard to tell the two apart as FODMAPs cause similar gastrointestinal symptoms than gluten sensitivity (bloating, flatulence, abdominal pain, diarrhea, and constipation). FODMAPs may also trigger skin problems in sensitive people (such as yours truly).

Wheat is one of the most problematic foods for people with FODMAP sensitivity. When people go on gluten-free diets, they often also eliminate many FODMAP rich foods, and the perceived improvements may be due to FODMAP elimination.

It’s important not to confuse the two. As some gluten-free foods, such as many gluten-free breads, contain lots of FODMAPs. One way to know is to go on gluten elimination diet and first to a re-challenge with gluten-free foods high in FODMAPs, such as:

  • Onions and leeks
  • Artichoke and asparagus

All of the above contain fructan, the same FODMAP found in wheat, rye, and barley.

For more on this, NPR has a good article on confusion between gluten and FODMAP sensitivities: Sensitive To Gluten? A Carb In Wheat May Be The Real Culprit.


There’s only one effective treatment for celiac disease and gluten sensitivity, cutting gluten out of the diet. Zonulin inhibitors show promise in preliminary clinical trials and could be an option in the future. But for now, the best we can do is to eliminate gluten from the diet.

The Celiac Disease Foundation has a lot more on the gluten-free diet.

Topical wheat sensitivity

A 2012 study showed that exposing the skin to wheat can cause contact allergy. In a patch test, 5 of the 14 women studied developed a mild to moderate irritation to wheat.

Many personal care and cosmetic products contain gluten. I believe that most people can use these without any problems. But for a small group of people, these can trigger skin irritation and itchiness. You can test this by switching to gluten-free products for a month or two.

Again, I want to emphasize that this is unlikely to be a problem for the vast majority of people reading this.

About Me

Hi, I am Acne Einstein(a.k.a. Seppo Puusa). I'm a bit of a science nerd who is also passionate about health. I enjoy digging through medical journals for acne treatment gems I can share here. You can read more about my journey through acne and how I eventually ended up creating this.


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