Looking to trim your waistline or boost your health by adopting a gluten-free diet? You may want to think twice before you give up the grain. A study in the April issue of The BMJ suggests that a gluten-free diet — in people who don’t have a medical reason to be on one — might unnecessarily raise your risk of heart disease if it means forgoing heart-healthy whole grains.
“If a woman is thinking about starting a gluten-free diet to lose weight or prevent heart disease, it might not be the best option,” says Dr. Andrew Chan, associate professor of medicine at Harvard Medical School and one of the study’s authors.
Gluten and the gut
Gluten is a type of protein that is found in grains such as barley, wheat, and rye, among others. It’s important to note that some people do have a good — and medically necessary — reason to avoid it. This includes people with a condition called celiac disease, an autoimmune disorder triggered by gluten. If these individuals eat gluten, it can cause a reaction in their body that damages the small intestine and limits the body’s ability to absorb nutrients. A second, less severe condition is called gluten sensitivity, which, unlike celiac disease, won’t actually damage the intestines. It does cause some pretty unpleasant symptoms, including cramping, tiredness, stomach pain, and leg numbness. For people with gluten sensitivity, going gluten-free is also a smart choice.
But for most women, the chance of having one of these conditions is low. Only 0.7% of the population has celiac disease, according to a 2016 study in The Journal of the American Medical Association (JAMA), a proportion that seems to be holding steady over time. Yet while only a small number of people actually have a medical condition that makes it difficult for them to tolerate gluten, the JAMA study also showed that the number of people on gluten-free diets is surging. The study authors speculated that people may stop eating food containing gluten because they think it’s healthy to go gluten-free or because they mistakenly think they have gluten sensitivity.
Lots of claims, little evidence
You may have heard claims that going gluten-free can do everything from improving your mood to helping with weight control to reducing your cancer risk, says Dr. Chan. The problem is that researchers haven’t confirmed whether any of these claims are actually true, although studies are in the works, he says.
While there isn’t much evidence that eliminating gluten brings any special health benefits for the average woman, the new BMJ study suggests that it may actually be less healthy. Researchers focused on information collected from 64,714 women and 45,303 men in two different studies. None had a history of heart disease.
Participants in the studies were asked to complete a food-frequency questionnaire every year from 1996 through 2010. Researchers then analyzed who went on to develop heart disease. They found that people who ate gluten weren’t more likely to develop heart disease than those who didn’t. But researchers also noticed that people who cut out gluten ended up eating a smaller amount of whole grains. “Eating whole grains is associated with a lower risk of heart disease,” says Dr. Chan.
What this means for you
So, how can you use these findings to decide whether to embrace gluten or avoid it?
Figure out if gluten is really the problem. Dr. Chan says that the evidence to date shows that gluten-free diets should be reserved for people who have a health reason to avoid gluten, such as celiac disease or gluten sensitivity. If you have symptoms that you think are triggered by gluten, ask your doctor to test you for celiac disease. There is no test for gluten sensitivity, but your doctor may suggest you make dietary changes to find out if gluten is the culprit.
Be skeptical. In the diet world, “experts” are always promoting the next big thing, but science often doesn’t back them up. “I think the low-fat phenomenon is a good example of a situation where some people take it to the extreme and cut out all fat, and as a consequence substitute foods that are harmful, such as sugar and refined grains,” says Dr. Chan. Many people adopted low-fat lifestyles in pursuit of better health, but ultimately may have done more harm than good. So, think twice before you jump on the next dietary bandwagon. “I think the take-home message from this study is that we should approach any diet that has very restrictive features with caution,” says Dr. Chan. “A lot of diets get popularized by the lay press or dietary gurus, when there is really little information to substantiate their claims.”
Seek balance. A well-rounded diet is typically best for most people. “If you have a balanced diet, which includes a variety of healthy food groups, you are probably in the best position to achieve health benefits,” says Dr. Chan. “Diets that rely on eliminating large food groups end up getting people into trouble because they may be restricting certain nutrients.”
