Celiac disease (CD) is an autoimmune disorder where ingesting gluten triggers an immune response that damages the lining of the small intestine. Fatty liver disease (FLD), also known as hepatic steatosis, describes the accumulation of excess fat within liver cells. For individuals with undiagnosed or untreated CD, liver abnormalities are frequently observed, confirming a clear connection between the two conditions. This liver involvement is often one of the first signs of CD, presenting as an extra-intestinal manifestation.
Understanding Fatty Liver Disease
Hepatic steatosis is defined by fat accounting for more than five to ten percent of the liver’s weight. While typically benign, this fat accumulation can progress to inflammation and scarring over time. Fatty liver disease is broadly categorized based on its cause, separating it from conditions caused by excessive alcohol consumption.
The form linked to metabolic issues was historically called Non-Alcoholic Fatty Liver Disease (NAFLD). It is now termed Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD) to reflect its strong association with metabolic factors like insulin resistance and obesity. MASLD is the type of fatty liver disease that shows a significant overlap with the underlying systemic issues present in individuals with Celiac Disease.
The Confirmed Connection Between Celiac Disease and Fatty Liver
The link between Celiac Disease and liver changes is well-documented, often manifesting before the CD diagnosis itself. Newly diagnosed, untreated CD patients often present with mildly to moderately elevated liver enzymes. This elevation is found in approximately 15 to 55 percent of newly identified patients, with a meta-analysis placing the overall prevalence around 21 percent.
Beyond enzyme elevation, ultrasound or biopsy reveals that hepatic steatosis is present in a significant percentage of patients at the time of CD diagnosis. Studies show that steatosis affects around 26 percent of newly diagnosed individuals. This liver involvement is considered an “extra-intestinal manifestation,” meaning the damage occurs outside the small intestine, driven by the systemic effects of the untreated gut condition.
How Celiac Disease Drives Liver Changes
The inflammatory and damaging effects of untreated Celiac Disease create several pathways that stress the liver, contributing to fat accumulation. One primary mechanism is chronic systemic inflammation originating from the damaged small intestine. The body’s ongoing immune response to gluten releases inflammatory signaling molecules that travel through the bloodstream, directly impacting liver function and promoting fat deposition.
Another significant pathway involves increased intestinal permeability, often referred to as “leaky gut,” which is characteristic of active CD. The compromised gut barrier allows bacterial products and toxins to pass from the intestine into the portal circulation. The liver, which is the first organ to receive blood from the gut, is forced to process these substances, triggering an inflammatory reaction and contributing to steatosis.
The condition can also lead to metabolic and nutrient issues that indirectly affect the liver. Historically, severe malabsorption and malnutrition in advanced CD could result in a specific form of steatosis due to protein and nutrient deficiencies. Conversely, the body’s altered metabolism and inflammatory state may lead to insulin resistance, which is a powerful driver of fat storage in the liver. This combination of systemic inflammation and metabolic dysregulation makes the liver susceptible to steatosis development.
Resolution Through Gluten-Free Diet
The Gluten-Free Diet (GFD), the primary intervention for Celiac Disease, is effective in resolving associated liver abnormalities. By eliminating gluten, the small intestine lining can heal, stopping the autoimmune attack and reversing the source of chronic inflammation and intestinal permeability. This healing process reduces the flow of inflammatory signals and toxins to the liver, allowing the organ to recover.
Following GFD initiation, the elevated liver enzymes begin to normalize within a few months to a year. Concurrently, the hepatic steatosis seen at diagnosis frequently resolves or significantly improves as the underlying CD enters remission. The reversibility of the steatosis underscores that the liver damage was directly linked to the active, untreated Celiac Disease.
The GFD itself can introduce new risks if not carefully managed. Many commercially available gluten-free processed foods are high in refined carbohydrates, sugars, and saturated fats to improve flavor and texture. Consuming a diet rich in these items can lead to weight gain and metabolic syndrome, which in turn can cause MASLD, even when CD is well-controlled. While the GFD treats the CD-related liver issues, long-term monitoring and a focus on whole, naturally gluten-free foods remain important for preventing other forms of fatty liver disease.