Is gluten bad for your health? What does the science say?

5 min read

Gluten free diets - a hugely marketed subject, and one that has caused much contention over the last few years. A quick search on Google will see a whole range of articles and opinions both for and against them.

Just don’t go ditching the pasta and pizza in too much of a hurry. Unless you suffer from celiac disease or have a gluten allergy, it’s unlikely that going gluten free will improve your health or benefit you in any way. You’ll just miss pasta and pizza. A lot.

Before we go any further, it’s worth explaining what gluten actually is, what it does and what effect it has on the body.

What is gluten?

Gluten is a group of proteins (called gliadin and glutenin)(1), which are present in many grains.

Gluten containing grains include:

  • Wheat (including varieties of wheat such as spelt and farro)
  • Barley
  • Rye

These proteins are responsible for giving dough its sticky and stretchy properties.

Oats are often thought to contain gluten but they are, in fact, naturally gluten free. Because they are commonly grown next to, and manufactured in the same facilities as wheat, barley and rye, many celiacs avoid eating them, just to be safe.

bread I made
A loaf of freshly baked bread, containing wheat gluten, on a breakfast table.

Why is there so much discussion about gluten being bad for you?

Gluten does cause issues for some people in the form of an autoimmune response.

This is seen in autoimmune diseases and disorders such as:

  • Celiac disease
  • Duhring’s disease (aka dermatitis herpetiformis)
  • Gluten ataxia

It can also trigger an allergic response. These include:

  • Food allergy
  • Contact dermatitis
  • Anaphylaxis

In the cases above, it is essential to follow a gluten free diet, in order to avoid suffering from the symptoms related to each condition. These conditions have all been well studied and defined. If you think you may be gluten intolerant, it is advised that you visit your GP.

Unlike many of the current sensitivity test kits you can buy, which test you for sensitivities using poor methodology, your GP will be able to give you a definitive answer, using proven methods.

Is gluten sensitivity the same as gluten intolerance?

These two terms are often used interchangeably. Sensitivity is different to intolerance, in terms of severity.

There do appear to be some people who suffer from something called non-celiac gluten sensitivity.

Potentially, 0.6-6% of people(2) whom are neither auto-immune or allergic. Unfortunately, there isn’t a method to test for this yet, and there isn’t a defined explanation as to why this sensitivity seems to have occurred; yet evidence is mounting for its legitimacy, at least.

However, the vast majority of the public do not have one of the above conditions, and, therefore, shouldn’t need to avoid gluten.

Why do people believe the myth that gluten is bad?

A potential reason for the increase in this myth’s popularity could be due to people cutting gluten out of their diet and, with it, removing high calorie foods e.g. cake, biscuits, and pizza. As a result, you often lose weight and feel better than you previously did.

This then leads to the belief that the weight loss is a direct result of removing gluten from your diet, when in fact you have simply decreased the amount of calories you consume!

Along with the calorie deficit you have ‘accidentally’ created, you are likely to have increased the overall quality of your diet by replacing nutritionally inferior foods for more fruit and veg, which are packed with vitamins and minerals.

As a result, you feel:

  • more energetic
  • have less gas
  • experience more healthy bowel movements

The improvement in health is likely nothing to do with the elimination of gluten, rather the introduction of more nutritious foods.

lido’s pasta
A dinner table of gluten-containing foods like pizza and pasta - eliminating these foods could aid weight loss, not because of the gluten, but because of the reduction in overall calories.

This belief that weight loss and increase in overall health is a direct result of removing gluten, leads to negative marketing surrounding it. More people follow the trend, experience the same positive results and all of a sudden gluten is the enemy and the supermarkets are exploding with expensive, gluten free alternatives.

It’s certainly a money maker!

Why does gluten cause bloating?

Another cause may be the claim that gluten is to blame for bloating(3). As bloating is a symptom of celiac disease, it is often a go-to explanation.

However, bloating can occur for one of several reasons. Conditions such as irritable bowel syndrome (IBS), irritable bowel disorder (IBD) and other food intolerances are common causes. Therefore, it is short sighted to assume that bloating is solely caused by gluten.

Obviously if you eat a massive meal and feel bloated as a result, this is more likely to be due to food volume than anything else.

If you are regularly bloated, I would suggest trying to identify the cause by noting when it occurs and what, if anything, you have eaten or drank prior to this episode.

If the symptom persists, and/or it causes you considerable distress, consider speaking to your GP, nutritionist or dietitian for more advice.

Can’t gluten cause a leaky gut?

Leaky-gut (it sounds worse than it is), is another name for increased intestinal permeability. That is the increase of food particles passing through the cells lining the gut wall into the rest of the body.

Alternative medicine practitioners claim this to be the cause of an array of issues affecting the various systems in the body, however, this has not been backed by research.

Increases in intestinal permeability occur naturally in the body, to allow larger molecules to pass through the gut lining into the bloodstream more easily.

In healthy individuals, this then returns to its original state and there is no issue. Medically, there is no evidence to suggest that this is a harmful process, and is perfectly normal.

Increased intestinal permeability is often seen in bowel conditions such as IBD (inflammatory bowel disease), celiac disease and post-chemotherapy, and is a symptom rather than a cause of said conditions(3).

In reality, this tends to lead to inflammation of the gut lining, as opposed to resulting in ‘leaking’ as the name would lead you to believe.

When we eat foods containing gluten, an increase in intestinal permeability occurs in order to allow the passage of the gluten molecules through the gut lining into the bloodstream, where it can be cleared by the bodies immune system(5).

In a non-celiac individual, this would not lead to any issues. Yet in those with celiac disease, this immune response is significantly heightened leading to the associated symptoms.

Do I need to go gluten-free?

  • Unless you have been diagnosed with celiac or Duhring’s disease or are allergic, the simple answer is, no, you don’t need to avoid gluten.
  • If you feel better when you cut gluten out of your diet, there is no reason why you have to eat it either.
  • If you substitute some high calorie gluten containing foods with more nutritionally dense foods like vegetables, this is likely to lead to an overall calorie reduction (and probable weight loss), along with improved dietary quality.

Going gluten free won’t cause you any harm, but it can make life more challenging and expensive if you want to replace all of your pasta and bread with the gluten free variety.

So, if you don’t experience any negative symptoms when you eat a slice of bread or some pasta, then you can relax, and just enjoy the food you are already consuming.

If you have been diagnosed with coeliac disease and would like further information on how to adapt your diet, visit Coeliac UK.


Tony Cottenden

An MNU Certified Nutritionist, PTC qualified Personal Trainer and founder of Topconditionpt.com. Tony is passionate about helping busy adults reach their health and fitness goals.