Gluten-free diet can do more harm than good for people without coeliac disease, scientists say

Avoiding wheat, barley and rye in the belief that a gluten-free diet brings health benefits may do more harm than good, according to a team of US nutrition and medicine experts.

For people with coeliac disease, a condition that affects one per cent of the population, gluten triggers a gut reaction that prevents the absorption of nutrients, causing painful symptoms including bloating, diarrhoea and nausea.

Gluten-free food has become increasingly popular among people without the disease who perceive it as healthy, with global sales up 12.6 per cent last year, compared to four per cent for packaged foods overall.

However, gluten consumption does not appear to increase the risk of heart disease, and abstaining from the protein can reduce intake of healthy whole grains, found the researchers.

The team of 13 scientists from institutions including Harvard and Columbia University in New York said gluten-free diets “should not be recommended” to otherwise healthy people with the aim of preventing heart disease.

“Concern has arisen in the medical community and lay public that gluten may increase the risk of obesity, metabolic syndrome, neuropsychiatric symptoms, and cardiovascular risk among healthy people,” they wrote in the British Medical Journal (BMJ).

“As a result, diets that limit gluten intake have gained popularity.” In the US, nearly 30 per cent of adults claim to have cut down on or be actively avoiding foods.

The researchers analysed data on more than 100,000 people with no history of coronary heart disease, who completed a detailed food questionnaire every few years from 1986 to 2010.

After adjusting the results for influencing factors, they concluded there was no significant association between estimated gluten intake and the risk of developing heart disease.

Among the 64,714 women and 45,303 men, all health professionals, who took part in two similar studies into their diet and health, those who ate more gluten also ate more whole grains.

“Whole grain intake has been found to be inversely associated with coronary heart disease risk and cardiovascular mortality,” wrote the researchers.

“These findings underscore the potential that people who severely restrict gluten intake may also significantly limit their intake of whole grains, which may actually be associated with adverse cardiovascular outcomes.”

They concluded: “The promotion of gluten-free diets for the purpose of coronary heart disease prevention among asymptomatic people without celiac disease should not be recommended.”

Symptoms of coeliac disease can be mild or severe and can include intestinal damage, hair loss and anaemia. It is treated by a patient following a gluten-free diet for life.