Gluten is incredible for its ability to piss off a diverse spectrum of people: folks who are giving it up for a diet, folks who say it’s stupid to give up gluten, and folks with coeliac disease who probably just wish they could avoid their symptoms and their gluten in peace.
A team of researchers is trying to add data to the question of whether or not a gluten-free diet has health benefits, with a new study that analyses questionnaires filled out by over a hundred thousand people. They’ve concluded that those who don’t suffer from coeliac disease or a wheat sensitivity shouldn’t avoid gluten. They think there may even be harm in doing so—but others aren’t so sure about that.
“There’s a lot of interest in the lay public regarding gluten free diet,” study author Andrew Chan from Harvard Medical School told Gizmodo. “There are many individuals who are adopting a gluten free diet [hoping] it will improve their health and prevent them from developing problems like heart disease. But that hasn’t been critically examined.”
The dataset the authors used in the paper, published today in the British Medical Journal, wasn’t specifically collected to study gluten-free diets. Around 65,000 women from the Nurses Health Study, which started in 1976, and 45,000 men from the Health Professional’s Follow-up Study that started in 1986, completed a questionnaire about the foods they ate every four years, leading up to 2010.
The researchers estimated the participants’ gluten intake based on the answers to the questionnaire, and compared those estimates to the incidence of coronary heart disease. Their estimates showed that a lower-gluten diet was associated with a lower chance of disease. But when they made another tweak to their analysis, analysing the subjects for differences in their whole grain intake, they found that more gluten consumption was associated with a lower risk of heart disease—possibly because people weren’t getting the benefits from eating whole grains.
“It raised the possibility that if you adhere long term to a gluten free diet, then you miss other essential nutrients and that might have a negative effect,” said Chan.
Other nutritionists agreed with the assessment that you shouldn’t adopt a gluten free diet if you don’t have to.
“I think it was an important study to do because so many times people get excited about these very extreme diets and assume that they’re going to be better,” Alice Lichtenstein, Senior Scientist and Director of the Cardiovascular Nutrition Laboratory from Tufts University told Gizmodo. She says that this study adds clarity to whether this sort of fad diet has benefits.
Alessio Fasano, Chair of Paediatric Gastroenterology and Nutrition at Massachusetts General Hospital and coeliac disease expert, agreed that gluten free diets are unnecessary for those who don’t suffer from coeliac disease or a non-coeliac wheat sensitivity. But he didn’t find the study’s results compelling. He pointed out that the datasets, though large, are not intended to study gluten-free versus gluten-filled diets. “When you do stuff like this in which you have to make all these assumptions, you wonder how close it is to reality,” he told Gizmodo. He compared the study to trying to build a boat with motorcycle parts. “I don’t believe in going gluten free [when there’s no] medical necessity, but the evidence doesn’t come from this study.”
The coeliac Disease Foundation also issued a statement on behalf of the study’s first author, Benjamin Lebwohl of the coeliac Disease Center at Columbia University Medical Center. He agrees with his study’s results and its conclusion, that gluten-free diets don’t have cardiovascular benefits and could lead to worse health from fewer whole grains. But Lebwohl points out that “more research is necessary to determine additional future health implications of a gluten-free diet in people without coeliac disease or non-coeliac gluten/wheat sensitivity.”
So, what should you do? Lichtenstein suggests you just find a diet that works for you, one that includes foods you actually like to eat. “You just have to figure out a basic framework,” one you actually enjoy and will enjoy ten years from now, she said. “That’s what you’ll really sustain. The important thing is the long term.” [BMJ]