When it comes to diagnosing celiac disease, people often overlook one crucial step—eating gluten before undergoing testing. If you suspect celiac disease and have already started a gluten-free diet, this step may seem counterintuitive. However, continuing to consume gluten before taking the test actually plays a vital role in obtaining accurate results. In this blog, we’ll discuss the importance of eating gluten prior to a celiac test, the effects of going gluten-free too soon, and the recommended pre-testing levels of gluten consumption.
The Celiac Disease Testing Process
Celiac disease is an autoimmune disorder that affects about 1 percent of the world’s population. It’s an autoimmune disorder that occurs when the immune system attacks the small intestine upon ingestion of gluten, causing inflammation and damage to the intestinal lining. Doctors use blood tests, genetic testing, and intestinal biopsies to diagnose celiac disease.
Blood Tests and the Gluten Challenge
When the immune system reacts to gluten, it produces specific antibodies—anti-tissue transglutaminase (tTG) and anti-endomysial (EMA)—which blood tests for celiac disease look for. When an individual has already started a gluten-free diet, these antibodies begin to decrease, leading to potential false-negative test results. To accurately assess the presence of these antibodies, it’s essential to continue eating gluten before testing. This is also referred to as a “gluten challenge.”
Genetic Testing and HLA-DQ2/DQ8 Genes
While not a definitive diagnostic tool, genetic testing can provide valuable information in the diagnostic process. About 95 percent of those with celiac disease have either the HLA-DQ2 or HLA-DQ8 gene. If genetic testing reveals that an individual does not carry either of these genes, it is highly unlikely they have celiac disease.
Intestinal Biopsies: Evaluating Damage
Many doctors consider intestinal biopsies the gold standard for diagnosing celiac disease. This test involves taking a small tissue sample from the small intestine to assess the damage done by the immune system’s response to gluten. If an individual has already started a gluten-free diet, the healing process may have begun, making it difficult to accurately assess intestinal damage.
The Risk of Going Gluten-Free Too Soon
The biggest reason you need to eat gluten before a celiac disease test is that beginning a gluten-free diet before testing for celiac disease can lead to inaccuracies in test results and, ultimately, misdiagnosis. Incorrect results not only provide false reassurance, but they may also delay proper diagnosis and treatment, increasing the risk of developing long-term complications such as nutritional deficiencies, osteoporosis, and an increased risk of certain cancers.
The Necessary Duration of Gluten Consumption
Experts recommend consuming gluten for at least six weeks before undergoing blood tests and biopsies for celiac disease. They suggest an individual consumes the equivalent of at least two slices of bread per day during this time. This ensures the immune system has an adequate response to gluten, boosting the chances of accurate test results.
One of the most crucial preparations for a celiac test is to consume gluten as usual. Starting a gluten-free diet prematurely can lead to false-negative results and misdiagnosis, jeopardizing one’s long-term health. Speak with your healthcare provider about the appropriate gluten consumption duration and the proper testing methods to guarantee the most accurate diagnosis and appropriate steps toward better health.