Gluten is controversial these days. Most sources claim that it is safe for everyone except those who have celiac disease. On the other hand, some health experts believe that gluten is harmful for most people.
According to a recent survey, more than 30% of Americans actively try to avoid eating gluten.
This article explains what gluten is, and how it can affect your health.
What is gluten?
Gluten is a family of proteins found in grains like wheat, rye, spelt and barley.
Of the gluten-containing grains, wheat is by far the most commonly consumed.
The two main proteins in gluten are glutenin and gliadin. Gliadin is responsible for most of the negative health effects (1, 2).
When flour is mixed with water, the gluten proteins form a sticky network that has a glue-like consistency.
This glue-like property makes the dough elastic, and gives bread the ability to rise when baked. It also provides a chewy, satisfying texture (3, 4).
Interestingly, the name glu-ten is derived from this glue-like property of wet dough.
Bottom Line: Gluten is a family of proteins found in grains like wheat, spelt, rye and barley. Gliadin and glutenin are the two main gluten proteins.
Problems with gluten
Most people tolerate gluten just fine.
However, it can cause problems for people with certain health conditions.
This includes celiac disease, gluten sensitivity, wheat allergy and some other diseases (5, 6).
Celiac disease, also spelled as coeliac disease, is the most severe form of gluten intolerance. It affects about about 0.7-1% of the population (7).
It is an autoimmune disorder, and involves the body treating gluten as a foreign invader. The immune system attacks the gluten, as well as the lining of the gut (8).
This damages the gut wall, and may cause nutrient deficiencies, anemia, severe digestive issues and an increased risk of many diseases (9).
The most common symptoms of celiac disease are digestive discomfort, tissue damage in the small intestines, bloating, diarrhea, constipation, headache, tiredness, skin rashes, depression, weight loss and foul-smelling feces (10, 11).
However, some people with celiac disease do not have digestive symptoms, but may have other symptoms like tiredness or anemia (12, 13).
For this reason, celiac disease can be very difficult to diagnose. In fact, up to 80% of people with celiac disease don’t know that they have it (7, 14).
Bottom Line: Celiac disease is an autoimmune disorder that makes the body attack gluten in the digestive system. This can cause severe digestive disorders and other health problems.
Non-celiac gluten sensitivity
There are many people who do not test positive for celiac disease, but still react negatively to gluten.
This condition is called non-celiac gluten sensitivity.
It is currently not known how many people have this condition, but it has been estimated to be in the range of 0.5-13% (15).
Symptoms of gluten sensitivity include diarrhea, stomach pain, tiredness, bloating and depression.
There is no clear definition of non-celiac gluten sensitivity, but the diagnosis is made when a patient reacts negatively to gluten, but celiac disease and allergies have been ruled out (16, 17, 18, 19).
However, some experts believe this isn’t a real condition. They think the adverse effects are imaginary or caused by substances other than gluten.
One study looked at almost 400 people with self-diagnosed gluten intolerance, and investigated whether they improved on a gluten-free diet (20).
The results showed that only 26 people had celiac disease, while 2 had a wheat allergy. Only 27 of the remaining 364 people were diagnosed as gluten sensitive.
That means that of the 400 who thought they were gluten intolerant, only 55 people (14.5%) actually had an issue with gluten.
Therefore, many people who think they’re gluten intolerant actually have other causes for their symptoms.
Bottom Line: Many people react negatively to gluten but do not have celiac disease. This condition, known as non-celiac gluten sensitivity, is controversial.
Irritable bowel syndrome
Irritable bowel syndrome (IBS) is a common digestive disorder that causes symptoms like abdominal pain, cramping, bloating, gas and diarrhea (21).
It’s a chronic condition, but many people are able to manage their symptoms with diet, lifestyle changes and stress management.
Interestingly, studies have shown that some individuals with IBS may benefit from a gluten-free diet (22, 23, 24, 25).
For about 1% of the population, a wheat allergy may be causing digestive issues after consuming gluten (26).
Furthermore, studies have shown that a gluten-free diet may benefit some individuals with schizophrenia, autism and a disease called gluten ataxia (27, 28, 29).
Bottom Line: Gluten may be problematic for people with irritable bowel syndrome and wheat allergy. People with schizophrenia, autism and gluten ataxia may also benefit from a gluten-free diet.