Is Gluten Sensitivity Real? A Critical Look

Gluten is a family of proteins in wheat, spelt, rye, and barley. Of the gluten-containing grains, wheat is the most commonly consumed.

The two main proteins in gluten are gliadin and glutenin. When flour is mixed with water, these proteins bind into a sticky network that’s glue-like in consistency (3, 4, 5).

The name gluten comes from these glue-like properties.

Gluten makes dough elastic and allows bread to rise when heated by trapping gas molecules inside. It also provides a satisfying, chewy texture.

SUMMARY

Gluten is the main protein in several grains, including wheat. It has certain properties that make it very popular for making bread.

A few health conditions are related to wheat and gluten (6).

The best known of these is gluten intolerance, of which the most severe form is celiac disease (7).

In people with gluten intolerance, the immune system mistakenly thinks that gluten proteins are foreign invaders and attacks them.

The immune system also fights natural structures in the gut wall, which can cause severe harm. The body’s assault against itself is why gluten intolerance and celiac disease are classified as autoimmune diseases (8).

Celiac disease is estimated to affect up to 1% of the U.S. population. It seems to be on the rise, and the majority of people with this condition do not know that they have it (9, 10, 11).

However, non-celiac gluten sensitivity is different than celiac disease and gluten intolerance (12).

Though it doesn’t work in the same way, its symptoms are often similar (13).

Another condition known as wheat allergy is relatively rare and probably affects under 1% of people globally (14).

Adverse reactions to gluten have been linked to numerous other conditions, including gluten ataxia (a type of cerebellar ataxia), Hashimoto’s thyroiditis, type 1 diabetes, autism, schizophrenia, and depression (15, 16, 17, 18, 19, 20, 21).

Gluten is not the main cause of these diseases, but it maymake symptoms worse for those who have them. In many cases, a gluten-free diet has been shown to help, but more research is needed.

SUMMARY

Several health conditions involve wheat and gluten. The most common ones are wheat allergy, celiac disease, and non-celiac gluten sensitivity.

In recent years, gluten sensitivity has received significant attention both from scientists and the public (2).

Put simply, people with gluten sensitivity experience symptoms after ingesting gluten-containing grains and respond positively to a gluten-free diet — but do not have celiac disease or wheat allergy.

People with gluten sensitivity usually do not have damaged gut lining, which is a key feature of celiac disease (12).

Yet, it’s scientifically unclear how gluten sensitivity works.

Growing evidence suggests the involvement of FODMAPs, a category of carbs and fiber that may cause digestive discomfort in some people (22).

Because no reliable lab test can determine gluten sensitivity, a diagnosis is usually made by eliminating other possibilities.

This is one proposed diagnostic rubric for gluten sensitivity (23):

1. Gluten ingestion causes immediate symptoms, either digestive or non-digestive.
2. Symptoms disappear quickly on a gluten-free diet.
3. Reintroducing gluten causes the symptoms to reappear.
4. Celiac disease and wheat allergy have been ruled out.
5. A blinded gluten challenge confirms the diagnosis.

In one study in people with self-reported gluten sensitivity, only 25% fulfilled the diagnostic criteria (24).

People with gluten sensitivity have reported numerous symptoms, including bloating, flatulence, diarrhea, stomach pain, weight loss, eczema, erythema, headaches, fatigue, depression, and bone and joint pain (25, 26).

Keep in mind that gluten sensitivity — and celiac disease — often have various mysterious symptoms that can be hard to link to digestion or gluten, including skin problems and neurological disorders (27, 28).

While data is lacking on the prevalence of gluten sensitivity, studies suggest that 0.5–6% of the global population may have this condition (6).

According to some studies, gluten sensitivity is most common in adults and much more common in women than men (29, 30).

SUMMARY

Gluten sensitivity involves adverse reactions to gluten or wheat in people who do not have celiac disease or wheat allergy. No good data is available on how common it is.

Several studies suggest that most people who believe they’re gluten sensitive don’t react to gluten at all.

One study put 37 people with irritable bowel syndrome (IBS) and self-reported gluten sensitivity on a low-FODMAP diet before giving them isolated gluten — instead of a gluten-containing grain like wheat (31).

Isolated gluten had no dietary effect on the participants (21).

The study concluded that these individuals’ supposed gluten sensitivity was more likely a sensitivity to FODMAPs.

Not only is wheat high in this specific type of carbs, but FODMAPs also trigger IBS symptoms (32, 33, 34).

Another study supported these findings. It revealed that people with self-reported gluten sensitivity didn’t react to gluten but to fructans, a category of FODMAPs in wheat (35).

While FODMAPs are currently believed to be the main reason for self-reported gluten sensitivity, gluten hasn’t been completely ruled out.

In one study, FODMAPs were the main trigger of symptoms in people who believed they were gluten sensitive. However, researchers speculated that gluten-triggered immune reaction contributes to the condition (36).

Nevertheless, many scientists assert that wheat sensitivity or wheat intolerance syndrome are more accurate labels than gluten sensitivity (37, 30).

What’s more, some studies suggest that modern strains of wheat are more aggravating than ancient varieties like einkorn and kamut (38, 39).

SUMMARY

FODMAPs — not gluten — may be the cause of digestive problems in non-celiac gluten sensitivity. Some scientists believe that wheat sensitivity is a more appropriate name for this condition.

Gluten and wheat are fine for some people but not for others.

If you react negatively to wheat or gluten-containing products, you can simply avoid these foods. You may also want to discuss your symptoms with a healthcare practitioner.

If you decide to abstain from gluten, choose whole foods that are naturally gluten-free. It’s best to steer clear of packaged gluten-free goods, as these are often highly processed.