As of 2017, over 3 million Americans follow a gluten-free diet for health reasons. But some researchers think people's sensitivity issues aren't always with gluten — they could be linked to fructan.
Fructans are naturally occurring carbohydrates common to American diets; wheat and onions make up about 95 percent of all fructans we eat. And while fructan and gluten have been linked to gastrointestinal problems in the past, the prevalence of celiac disease hasn't grown. But interest in gluten-free diets has.
So researchers wanted to see if people who thought they were gluten-intolerant were actually fructan-intolerant. Each week, they assigned participants a blind diet that was one of these: gluten, fructan or placebo. People then said how they felt before moving to the next diet.
When researchers compared the records, they found only about 1 in 5 people said they felt the worst on the gluten diet, while about 2 in 5 said they felt the worst on the fructan diet.
So many claiming to have gluten sensitivities might be focusing on the wrong thing. But gluten-free diets aren't without risks. Previous studies have also linked them to increased risk of heart disease and Type 2 diabetes.