Gluten-free diet may harm those who don't need it
For people without coeliac disease, there is no reason to go gluten-free and the diet may actually be harming them, says a US gastroenterologist.
Writing the Journal of Paediatrics, Dr Norelle Reilly from New York’s Columbia University Medical School notes that while only 0.5% of people in the US have been diagnosed with coeliac disease, over 20% claim to be following a gluten-free diet.
But it’s not necessarily a healthy lifestyle choice, she says.
Gluten-free packaged foods often contain more fat and sugar than their gluten-containing equivalents, Dr Reilly notes.
Studies have shown that people following a gluten-free diet are more likely to obese or overweight, with new-onset of insulin resistance and metabolic syndrome more common as well.
A gluten-free diet can also lead to deficiencies in vitamin B, folate and iron, Dr Reilly says.
There is also a greater exposure to certain toxins, with studies finding fourfold higher levels of mercury in coeliac adults following a gluten-free diet.
Arsenic levels too are often higher, as it is frequently present in inorganic form in rice, a common ingredient in gluten-free foods.
On the other side of the equation, Dr Reilly says there is no evidence that gluten can be toxic outside of coeliac disease. In fact certain studies have specifically demonstrated its lack of toxic effects, she notes.
Of course, there is the thorny subject of non-coeliac gluten sensitivity (NCGS), a generally self-diagnosed condition with unclear diagnostic criteria.
Dr Reilly says gluten-containing foods “may induce symptoms in certain individuals without coeliac disease”, but there is as yet no test for the disease, and many who claim to have it may in fact be suffering from a FODMAP intolerance.