How Common Is Celiac Disease?

Celiac disease is actually quite a common condition, but you wouldn't necessarily realize how common it is because so many people who have it haven't been diagnosed. Because celiac is a genetic condition — in other words, you need to have the "right" genes to develop it — the rate of celiac disease varies widely from country to country. 

In the United States, about one in every 141 people have celiac disease, which means approximately 1.8 million people have the condition. However, more than 2 million of these haven't yet been diagnosed, so they don't know they have the condition and therefore need to follow the gluten-free diet.

People with mainly Caucasian ancestry seem to have a much greater risk of developing the condition than those who have mainly African, Hispanic, or Asian ancestry.

For example, one large U.S.-based study found that 1% of non-Hispanic whites had celiac, compared with 0.2% of non-Hispanic blacks and 0.3% of Hispanics.

Another study found very high rates of celiac — around 3% — among people with North Indian (Punjab) ancestry, and low rates in those with East Asian, South Indian, and Hispanic ancestry. People with Jewish and Middle Eastern ancestry had rates of celiac disease that were about average for the U.S., but those with Ashkenazi Jewish ancestry had higher rates of celiac, while those with Sephardic Jewish ancestry had lower rates.

Surprisingly, that same study found similar rates of celiac in both men and women. Previous research had suggested that celiac is much more common in women.

Celiac disease is considered rare in countries where most people are not non-Hispanic white, although researchers also believe that its incidence is growing worldwide.

What Makes My Risk Higher or Lower?

In two words: your genes.

Celiac disease has been strongly linked to two particular genes: HLA-DQA1 and HLA-DQB1. Almost all people with celiac disease have specific variants of the HLA-DQA1and HLA-DQB1 genes. However, these variants are also found in 30 percent of the general population, and only 3 percent of individuals with the gene variants develop celiac disease.

Celiac disease tends to cluster in families. Parents, siblings, or children of people with celiac disease have between a 4 and 15 percent chance of developing the disorder. However, the inheritance pattern is unknown.

There are other factors in play, many of which medical researchers haven't determined yet. It appears likely that other contributors, such as environmental factors and changes in other genes, also influence the development of this complex disorder.

I Haven't Had A Gene Test, What's My Risk?

Even if you don't know what genes you carry, you may be able to judge your own risk based on your family's medical history, since those with a close relative who's been diagnosed also are at higher risk for celiac.

If you are a first-degree relative — parent, child, brother or sister — of a person with celiac disease, research shows you have a 1 in 22 chance of developing the disease in your lifetime. If you are a second-degree relative — aunt, uncle, niece, nephew, grandparent, grandchild, or half-sibling — your risk is 1 in 39.

Regardless of your personal risk for celiac disease, medical research shows it's a common (although underdiagnosed) genetically linked medical condition. In fact, according to the Wm. K. Warren Medical Research Center for Celiac Disease Research in San Diego, celiac disease is twice as common as ​Crohn's disease, ulcerative colitis, and cystic fibrosis combined.

(Edited by Jane Anderson)