Scientists at the University of Toronto have found that the majority of Torontonians with celiac disease (CD) remain undiagnosed. The study, published in BMJ Open, screened blood tests and questionnaires of nearly 3,000 adult participants of diverse backgrounds living in Toronto for antibodies found in people who are suffering from the disease.

The study was led by researchers from the U of T Department of Nutritional Sciences. Similar to prominent American and European studies conducted on the topic, they found that approximately one per cent of Torontonians are affected by the disease.

Previous surveys by the Canadian Celiac Health Survey showed a delay of about 12 years between symptom onset and diagnosis, suggesting the need for better screening for the disease in the Canadian population.

CD is an autoimmune disease caused by the body’s adverse reaction to gluten, a protein commonly found in wheat, barley, and rye. Symptoms can vary from gastrointestinal discomfort to skin rashes, fatigue, anemia, and weight loss.

The immune system of affected individuals reacts negatively to gluten and, over time, people can suffer from damaged intestinal walls. This can make it harder for people to absorb essential nutrients from food.

Although there is no known cure, the treatment for the disease is a gluten-free diet, which can help manage symptoms. This includes avoiding wheat and barley and consuming more fruits, vegetables, dairy, and gluten-free alternatives for grain products. Naturally gluten-free grains include rice, soy, and quinoa.

The Canadian Celiac Association warns those who may be affected by the dangers of hidden traces of glucose in processed and packaged foods. They suggest a list of gluten-free foods can be found on their website.

About 30 per cent of the American population carries the alleles linked to CD, but that is insufficient for the development of CD. Other environmental factors such as the timing of first gluten exposure and breastfeeding duration can influence the risk or its onset.

The gold standard for diagnosis is a small-bowel biopsy, but blood tests can be used as a screening tool. Blood tests can find antibodies present and should be conducted before and after an individual starts a gluten-free diet to track progress.

The study only screened participants using blood tests and did not use a biopsy to confirm a definitive diagnosis for celiac disease. The researchers indicate that their results may not be generalizable to the wider Canadian population.