Avoiding Gluten May Backfire in Terms of Coronary Risk in the General Population, Study Suggests

Reducing or eliminating gluten intake is an increasingly popular diet fad, but when the move is made without reason it may be doing more harm than good, at least in terms of coronary heart disease risk, a new analysis indicates.

In two cohort studies spanning decades, overall gluten intake was not associated with risk of fatal or nonfatal MIs in people without celiac disease. Where the protein came from seemed to make a difference, however. Greater consumption of refined grains also was not related to coronary risk, but people who ate the most whole grains carried a lower risk (HR 0.85; 95% CI 0.77-0.93).

“The avoidance of dietary gluten may result in a low intake of whole grains, which are associated with cardiovascular benefits,” researchers led by Benjamin Lebwohl, MD (Columbia University, New York, NY), write in their paper published online ahead of print in the BMJ. “The promotion of gluten-free diets for the purpose of coronary heart disease prevention among asymptomatic people without celiac disease should not be recommended.”

Gluten’s on the short list . . . of the reasons why there are problems in the universe. David Katz

Commenting for TCTMD, David Katz, MD (Yale-Griffin Prevention Research Center, New Haven, CT), said the study reaffirms what the mainstream nutrition community has known for some time, in that it “is among the many sources of information that have told us again and again and again and again that people who consistently eat whole grains have better health overall.”

The basic message, he said, “is that in efforts to avoid gluten because it’s now the popular thing to do, there appears to be a grave risk of tossing out the baby with the bath water.”

Gluten is a storage protein found in wheat, rye, and barley that causes inflammation and intestinal damage in patients with celiac disease, which is found in about 0.7% of Americans. Adhering to a gluten-free diet is an effective treatment.

But diets that reduce gluten or avoid it altogether have been growing in popularity among people without celiac disease in recent years because of perceived health benefits. Katz described gluten as the “latest boogeyman” in nutrition.

“I think we have such an oversimplified, dumbed-down approach to nutrition in this country that everybody’s always looking for a silver bullet or a scapegoat,” he said. “Gluten’s on the short list . . . of the reasons why there are problems in the universe. And most people who are attempting to avoid gluten don’t know why and don’t even really know what it is and have no notion about what it will do to the overall quality of their diet or health. They’re just doing it because they heard they should.”

The current analysis included data on 64,714 women participating in the Nurses’ Health Study and 45,303 men participating in the Health Professionals Follow-up Study after exclusion of those who reported a history of celiac disease. All participants filled out periodic food frequency questionnaires starting in 1986 and were followed until 2012.

Through roughly 26 years of follow-up, people eating the most gluten did not have a higher risk of MI compared with those eating the least after accounting for known risk factors (HR 0.95; 95% CI 0.88-1.02). The lower coronary risk seen with greater consumption of whole grains came in an analysis controlling for intake of refined grains.

Katz said that people with celiac disease “absolutely do need to avoid gluten, because that autoimmune disease can be devastating.” He added that another 5% to 10% of the population has a sensitivity to gluten.

“But still, 90% of the population has no gluten sensitivity, and I think this paper is one of the many reality-check papers for that group,” Katz continued. “The nine people in 10 who think they ought to cut gluten have no reason to do so really, and in the process of cutting gluten out of their diets will be jettisoning whole grains and actually degrading the quality of their overall diet and putting their health at risk.”