Gluten sensitivity and celiac disease are both popular subjects in the health and wellness space as more and more people are connecting their gastrointestinal symptoms to the consumption of grains such as wheat that contain the protein gluten. In fact, the gluten-free products market swelled to over $20 billion in 2020 – and has shown no signs of slowing down any time soon.
So what’s the science behind the celiac disease and gluten sensitivity? The answer – it’s complicated!
First of all, it’s important to understand that while the terms are frequently used interchangeably by the general public, there are important differences between celiac disease (CD) and non-celiac gluten sensitivity (NCGS) or non-celiac wheat sensitivity (NCWS). In short, celiac disease is an autoimmune disorder, whereas gluten intolerance is a dietary sensitivity.
Celiac disease is a genetic autoimmune disease where the gluten protein in wheat or other grains triggers antibodies that then attack the small intestine. Although the symptoms can mirror those of celiac disease, NCGS is neither an autoimmune disorder nor an allergy, and a genetic link has not yet been identified.
In celiac disease, the damage to the small intestine caused by the autoimmune response makes it difficult for nutrients to be properly absorbed by the body. This can cause fatigue, diarrhea, weight loss, bloating, and nausea, which are not symptoms usually tied to non-celiac wheat sensitivity.
Celiac disease is the most common genetically predisposed food intolerance, affecting approximately 1 in 100 individuals of the general population. Gluten sensitivity affects up to 6% of the population, making it the more common diagnosis.
What role does genetics play in celiac disease?
Celiac disease is a genetic disorder, and parents, siblings, or children of people with celiac disease have a 4 -15% chance of inheriting the disorder. HLA-DQA1 and HLA-DQB1 are the two genes that make a person with celiac disease symptomatic – these genes produce the antibodies in response to gluten that attacks the digestive system.
How can you tell whether your symptoms are caused by celiac disease or general gluten sensitivity? Genetic testing can provide answers.
Since the celiac disease has strong family heritability and can be determined by genetic markers in the HLA-DQA1/D2 and HLA-DQB1/D8 genes in almost 100% of cases – whereas NCGS or NCWS has a minimal association with other HLA gene markers – genetic testing of HLA markers can help rule out the possibility of celiac-related gluten sensitivity. When celiac disease is ruled out, it makes it much more likely that a person with symptoms would have NCGS or NCWS instead.
The good news is that although many people can inherit the genetic susceptibility to celiac disease, only a small percentage of those people (around 3%) will actually develop the disease. Like other complex diseases, other environmental factors play a significant role in the development of the condition.