Is Gluten Bad for You? A Dietitian Explains

by | Sep 24, 2024 | Uncategorized

This post was adapted from episode 68: “Is Gluten Bad for You? Dietitian Explains” of the Nourished & Free podcast.

Listen to the full episode for more information about food sensitivity tests

If you’ve spent any time looking at health and wellness content in the last 10 years, then chances are you’ve heard a lot about gluten-free diets. And all of this gluten-free talk may have left you wondering, “is gluten bad for you?”

From the paleo diet and keto diet to the auto-immune protocol and more, there are many “wellness” movements that put a lot of energy into avoiding gluten. But is a gluten-free diet really healthier?

Keep reading to learn more about the pros and cons of a gluten-free diet and discover if gluten is as unhealthy as it’s often made out to be. (Spoiler alert: it’s not.)

What is Gluten?

Before we can figure out whether gluten is worth cutting out of our diets, it’s important that we know just what we’re getting rid of.

Gluten is a protein found primarily in wheat, barley, and rye. It is responsible for giving dough its elasticity and structure, which is why it’s such a critical component in baking. While some people might only associate gluten with bread or pasta, it can also be found in many processed foods, sauces, and even beer. 

Essentially, gluten is a naturally occurring part of grains that humans have consumed for thousands of years. 

Bowls of gluten-free flours

Why Do People Avoid Gluten?

There are many different reasons people avoid gluten. But often, it’s because of misconceptions about its health effects. 

The most common reason some avoid gluten is celiac disease, an autoimmune disorder in which the consumption of gluten leads to damage in the small intestine. For those with celiac disease, gluten is truly unhealthy. But this condition affects only about 1% of the population. 

Others who avoid gluten may have non-celiac gluten sensitivity (NCGS) or may believe they are intolerant to gluten. Symptoms like bloating, fatigue, or other discomfort when consuming gluten are often associated with a sensitivity to gluten. But research on food intolerances vs food sensitivities is still developing, and many of the food sensitivity tests folks use to explore these issues are not accurate.

Some people also choose to avoid gluten because it’s perceived as inflammatory, or they believe gluten-free diets are healthier overall.

So, Is Gluten Really Inflammatory?

This is the ultimate question we’re exploring in today’s post and we’re doing it by looking at the science. Thankfully, the science is pretty clear: for the majority of people, gluten is not inherently inflammatory. 

The idea that gluten is broadly inflammatory often stems from confusion between gluten-related disorders like celiac disease and general dietary recommendations. In those with celiac disease, gluten can indeed trigger lasting inflammation as part of the body’s immune response. 

However, for people without these conditions, there is no strong evidence to suggest that gluten causes inflammation. In fact, whole grains that contain gluten, like wheat, are rich in fiber, vitamins, and minerals, and are associated with numerous health benefits including reduced risks of heart disease, diabetes, and certain cancers. 

A woman saying no to bread after wondering, "is gluten bad for you?"

6 Gluten Health Claims Fact-Checked by a Dietitian

So, how does gluten actually impact your health? Let’s take a deep dive into some of the claims commonly made about gluten and gluten-free diets.

Claim: Gluten is Inflammatory for Everybody

Let’s start with the biggest claim of all: that gluten is inflammatory for everyone. In a randomized cross-over trial, researchers found that a diet rich in whole-grain wheat (meaning, not gluten-free) was associated with a reduction of body weight and in systemic low-grade inflammation. This suggests gluten could potentially be anti-inflammatory. 

Other health benefits of whole grain wheat can be seen in another study too. This study was a placebo-controlled, parallel-group randomized trial comparing refined wheat products to whole grain products in regards to their impact on gut microbiota.

The study found an increase in fecal ferulic acid as well as serum dihydroferulic acid, which I don’t know a lot about and are a bit beyond the width of my knowledge, but from what I gather they are both ideal for maintaining good health.

Another way to decide if something is inflammatory is to see if it’s an aggravator for something like inflammatory bowel disease. A study utilizing data from the Nurses’ Health Study I, II, and the Health Professionals Follow-up Study (which is data following over 200,000 US participants and spanning from 1986-2017) found that gluten did not increase risk for inflammatory bowel disease.

Therefore, it is not recommended to eliminate gluten for anyone who does not have celiac disease (only about 1% of people) or non-celiac gluten sensitivity.

Claim: Gluten Increases Risk for Disease

While it’s possible to have a generally ‘disease-preventing’ diet that is gluten-free, it’s not the lack of gluten that is making the diet healthier (unless someone has celiac disease or non-celiac gluten sensitivity). 

In fact, we see in large prospective cohort studies that the risks of heart disease and diabetes actually go down with increased gluten intake, which we can infer is likely from the higher consumption of whole grains.

Claim: Gluten Causes Brain Fog

Brain fog is one of the most common symptoms you’ll hear people talk about while promoting a gluten-free diet. But the truth is, there’s no evidence to show that individuals without celiac disease experience brain fog due to gluten intake. 

Certainly some of those who have celiac disease report experiencing brain fog, and feeling better after adhering to a gluten-free diet, but that doesn’t mean that gluten has that effect on everyone. It doesn’t even have that effect on everyone with celiac disease!

A woman eating a cracker

Claim: A Gluten-Free Diet will Improve Hashimoto’s Disease

Those with Hashimoto’s Disease are often told as a blanket recommendation to go gluten-free, whether or not they have celiac disease. 

Hashimoto’s is an autoimmune disease impacting the function of the thyroid, causing hypothyroidism. Some researchers think there’s a connection between Hashimoto’s and gluten due to some structural similarities between the thyroid gland and gluten at the molecular level. However, there is no basis for requiring a gluten-free diet for those with Hashimoto’s if they do not also have celiac disease. 

There was a small pilot study published that made it seem like a gluten-free diet improved some clinical markers of Hashimoto’s. However, there was no baseline test for celiac disease beforehand to know if those markers improved because of the Hashimoto’s itself, or because those participants also happened to have celiac disease. 

Additionally, participants got to choose whether they follow the GF diet or not, and there were also no other regulations on dietary intake beyond the change in gluten-containing foods. 

With these key pieces of study design in mind, we can see this was a poorly controlled study. Why? Because individuals who had the motivation to go gluten-free may have also felt more motivated to make other changes and adopted a generally more anti-inflammatory diet compared to the other group. 

We have no way of knowing if the gluten itself was the difference or if it was overall dietary changes because the entire diet was not controlled for. Don’t forget, they also didn’t test for pre-existing celiac disease. Biomarkers would obviously improve in those who went gluten free if celiac disease was present beforehand.

Claim: A Gluten-Free Diet Helps Autism

There is no evidence to support this (much like there is no evidence to support many other claims about the causes and exacerbators of autism).

People like to talk about how gluten passes through a “leaky gut” and creates issues with behavior, but unless someone has celiac disease and Autism Spectrum Disorder (ASD), there’s no convincing data to show that gluten will worsen ASD.

Claim: Gluten-Free Foods are Healthier

This is such a common misconception! Gluten itself has nothing to do with the health-promoting potential of a food. Actually, many packaged gluten-free products are objectively less healthy due to having to make up for the loss of gluten. They may be higher in sugar, sodium, and saturated fat as they try to compensate for the change in flavor and texture when gluten is removed.

This is why it’s so important to look at the actual ingredients in a given food and not just blindly consume foods claiming to be gluten-free (or conforming to other food labels) and have the appearance of being healthier.

Bowls of gluten free flour, gluten free foods and gluten free pasta

What Happens When You Cut Out Gluten?

The effects of cutting out gluten depend on whether you have celiac disease or a non-celiac gluten sensitivity.

For people with celiac disease or NCGS, removing gluten from their diet can lead to significant health improvements. Those with celiac disease, for example, often experience reduced if not complete remission from gastrointestinal symptoms like bloating, diarrhea, and stomach pain.

Over time, cutting out gluten can also help improve nutrient absorption, help repair damage to the small intestine and reduce systemic inflammation caused by the immune response.

For those without a medical reason to avoid gluten, however, the effects of cutting it out can be mixed. 

While some people might notice an improvement in their digestive comfort, it could simply be because they’re paying more attention to the quality of food they’re eating and replacing processed foods with more whole, nutrient-dense options. 

However, eliminating gluten without a diagnosed need can also lead to unintended consequences, such as missing out on important nutrients. 

Whole grains containing gluten, like wheat, are rich sources of fiber, B vitamins, iron, and magnesium. A gluten-free diet can sometimes be lower in fiber and essential nutrients, especially if it relies heavily on processed gluten-free substitutes, which may be higher in sugar, fat, or calories.

Going gluten-free without a medical need can also have mental health and social impacts, such as increasing food costs and making parties or dining out more challenging. It can also contribute to unnecessary food fear and restriction, which can lead to an unhealthy relationship with food and even result in binging.

A woman eats pizza

So, Should Everyone Avoid Gluten?

In case you can’t already tell, as a dietitian I’m not a fan of cutting out gluten unless it is truly medically necessary. And because celiac disease and non-celiac gluten sensitivity are rare, it’s rarely going to significantly improve your health to cut out gluten.

In fact, going on a restrictive diet, such as a gluten-free diet, can even harm your relationship with food – a key aspect of your overall health and wellness.

So, if you don’t have a diagnosed gluten allergy, my dietitian advice would be to cut yourself some slack…and maybe a slice of some nice whole-wheat bread. 🙂 

Need support with overcoming a bad relationship with food? Contact me to learn more about working with a binge-eating dietitian and explore my Nourished & Free® binge eating coaching program.

Listen to the Nourished & Free podcast episode on this topic.