There is more risk than benefit to a gluten-free diet for people — especially children — who haven't been diagnosed with celiac disease or wheat allergy, according to the Journal of Pediatrics.
In a commentary that aims to separate fact from fiction, Dr. Norelle R. Reilly, of New York-Presbyterian/Columbia University Medical Center, says a gluten-free diet is not a healthy lifestyle choice.
"Parents should be counselled as to the possible financial, social, and nutritional consequences of unnecessary implementation of a gluten-free diet," said Reilly, who is a specialist in pediatric gastroenterology.
In 2015, 25 per cent of U.S. consumers reported consuming gluten-free foods, according to market research by the Mintel Group. The gluten-free industry more than doubled in size from 2013 to 2015.
Most of those consumers are eating gluten-free without checking with a dietitian or health professional, making it a fad that could be affecting thousands of children, Reilly said.
Books like David Perlmutter's Grain Brain and William Davis' Wheat Belly, have helped make the gluten-free food market a multi-billion-dollar industry, but dietitians are skeptical.
Reilly expressed concern about high levels of fat and sugar in gluten-free packaged foods, saying this could lead to increased caloric intake at a time when a high proportion of the population are struggling with obesity.
She also said a gluten-free diet may be lower in nutrients than one that includes wheat products, as ingredients are not fortified, leading to deficiencies in B vitamins, folate, and iron.
Rice and rice flours often substitute for wheat in gluten-free products, increasing the risk that people are consuming serum mercury and arsenic, which rice takes up naturally from the soil.
She also points to the higher cost of food and quality of life issues for children limited to a gluten-free diet, who would not be able to eat at a friend's home or to exchange treats with school friends.
Reilly said there is a misconception that gluten itself is toxic, which may be leading many people to adopt a gluten-free diet when they don't need to.
"Gluten, comprising gliadins and glutenins, is one of the many protein components of wheat and for the majority of people, gluten proteins pass through the gastrointestinal tract without leading to disease," she said.
Reilly said parents should be discouraged from putting their children on a gluten-free diet even where one member of the family has been diagnosed with celiac disease or a wheat allergy. Often the family will all eat gluten-free foods as a matter of convenience.
She acknowledges that celiac disease, which would warrant a gluten-free diet, is underdiagnosed in the U.S. and wheat allergy is rare. But she said there is little data about non-celiac gluten sensitivity in children.
However, putting a child on a wheat-free diet before celiac disease is diagnosed can obscure evidence of the disease, she said.
Parents may resist reintroducing foods with gluten which may be necessary to get a diagnosis, she added.
"Other conditions such as irritable bowel syndrome, small bowel bacterial overgrowth, and fructose and lactose intolerance may be responsible for symptoms in those self-diagnosed with gluten sensitivity," Reilly said in her commentary.
There is no evidence that delaying the introduction of gluten to infants has any impact on later development of celiac disease, she said. Most literature recommends introducing wheat-based products between six months and one year.
She urged people who adopt a gluten-free diet to seek the advice of a health professional.
"Health care providers may not be able to end the gluten-free diet fad, but can certainly begin to play a larger role in educating patients, excluding celiac disease, and preventing nutritional deficiencies in those choosing to stay gluten-free," she said.