Move over fat, salt, and sugar. There’s a new dietary villain in town and its name is gluten.
Scan the grocery aisles and it’s impossible to miss the proliferation of products proclaiming that they are “gluten-free.”
Pick up a magazine or go online and you are likely to read about yet another celebrity or athlete who has banished gluten from their diet.
By one estimate, as many as 18 million Americans have some degree of gluten sensitivity, but a new analysis raises questions about the claim and the benefits of a gluten-free diet for most people.
What is Gluten?
Gluten is a protein in wheat, rye, and barley that is commonly found in bread, beer, pasta, and a wide range of other processed foods containing these grains.
For about 1% of the population, eating gluten causes celiac disease, an intestinal condition characterized by the inability to absorb nutrients from food.
Celiac disease is diagnosed through blood and bowel tests, but there are no good tests to determine non-celiac gluten sensitivity, and there has been considerable debate about whether the condition even exists.
In their essay published in the Annals of Internal Medicine, Celiac researchers Antonio Di Sabatino, MD, and Gino Roberto Corazza, MD, of Italy’s University of Pavia, explored what is and is not known about gluten sensitivity and addressed the growing hype about the benefits of gluten-free eating.
“Claims [about gluten-free diets] seem to increase daily, with no adequate scientific support to back them up,” they write. “This clamor has increased and moved from the Internet to the popular press, where gluten has become the new diet villain.”
Gluten may not be to blame
The researchers noted that many symptoms attributed to gluten may actually be caused by sensitivity to other components of wheat flour or other ingredients found in wheat-based foods like bread, pasta, and breakfast cereals.
Symptoms that have been attributed to gluten sensitivity include diarrhea, abdominal cramping, bloating, headaches, fatigue, and even those associated with attention deficit hyperactivity disorder (ADHD).
Di Sabatino and Corazza write that some people may experience these symptoms when they eat foods containing gluten simply because they believe these foods will make them sick.
They conclude that common sense must prevail to “prevent a gluten preoccupation from evolving into the conviction that gluten is toxic for most of the population.”
'Gluten-free here to stay'
Pediatric gastroenterologist Alessio Fasano, MD, runs the Center for Celiac Research at the University of Maryland.
Fasano tells WebMD that his own research suggests that 5% to 6% of the population -- about 18 million Americans -- has some degree of gluten sensitivity.
While he concedes that many people who may not benefit have jumped on the gluten-free bandwagon, he says many others who do not have celiac disease or wheat allergies still benefit from following a gluten-free diet.
That is what many food manufacturers are likely counting on, with Anheuser-Busch, Kellogg’s, General Mills, and many others now promoting “gluten-free” versions of some of their best-selling products.
“I believe the fad of the gluten-free diet will not last,” he says. “But because there are many, many people who are truly gluten-sensitive and sick, the diet will not go away, either.”
Diet can be dangerous, expert says
Stefano Guandalini, MD, who is president of the North American Society for the Study of Celiac Disease, says the true prevalence of gluten sensitivity probably will not be known until biologic indicators exist to diagnose the disorder.
He adds that one very real danger of following a gluten-free diet is eating too much fat and too little fiber.
Guandalini is medical director of the University of Chicago Celiac Disease Center.
“Someone who needs to be on a gluten-free diet and is closely monitored can benefit tremendously from it,” he says. “But for everyone else, embracing this diet makes no sense.”