Gluten is a hot topic. You'll hear it dropped in reference to celiac disease, grain-free diets, sensitivity, weight loss, overall gut health and more. But though it feels like gluten is, like many celebrities, a tad overexposed, it's actually a relative newcomer to medical research.

Gluten is the glue-like substance that gives wheat, rye, oat and barley products their chewy structure. People who have gluten sensitivity or gluten intolerance tend to feel sick after they eat foods that contain gluten.

But as James Hamblin, M.D., writes for The Atlantic, studies about what gluten does or does not do to the body have increased over the last decade. Hamblin was in medical school as recently as 2007, and he remembers only one lecture on the topic:

After the lecturer mentioned "gluten," a classmate raised a hand and asked him to repeat himself. People who eat what?...

When someone with celiac disease eats gluten, it causes an immune reaction that destroys the lining of the small intestine. But as long as people with celiac disease avoid gluten, they’re fine. Got it. And like most medical doctors, that’s what I remember learning about gluten.

The push to take a closer look at gluten didn't come from doctors who were worried that it may harm our health (although, as Hamblin points out, some extremists believe that). After all, humans have been eating grains for centuries. Instead, doctors began studying gluten with greater intensity because their patients were interested in the topic and often were misinformed.

“I believe we need to research and study rigorously the things that patients are interested in,” Benjamin Lebwohl, a gastroenterologist with the Celiac Disease Center at Columbia University, told The Atlantic. “This is, in my view, a necessary part of science’s mission — to go to where the public is interested and provide sound analysis. If the public is barking up the wrong tree, we shouldn’t ignore that.”

The proof is in the (gluten-free) pudding

Following a gluten-free diet means saying no to toast. Skipping gluten if you do not have a gluten sensitivity may be worse for your overall health, not better. (Photo: Lolostock/Shutterstock)

Lebwohl said he has found that there's an important difference between telling patients "there’s no proof that gluten has health effects in the general population and saying that there is proof that gluten has no health effects in the general population." The latter statement is the one that holds more sway. Proof is key.

So as researchers aim to separate gluten fact from fiction, here's some of what science has proven so far:

1. Gluten does not hurt your heart. For people who do not have celiac disease, eating gluten does not increase heart disease risk, according to a new study published in The BMJ. In fact, the study found the opposite is true: Adopting a gluten-free diet (again, if you do not have celiac disease) may increase heart disease risk since it means fewer whole grains are being consumed.

For the study, researchers examined data from more than 173,000 health care workers who were followed for 10 to 20 years. They were separated into five groups based on how much gluten they ate. People who ate the least consumed about 3 grams per day, while people who ate the most ate between 8 to 10 grams a day. Researchers found that in terms of heart disease risk, there was no difference between the groups.

"We think this is very important, because this boom in gluten-free diets and all these claims that it’s beneficial to an individual's health to be on a gluten-free diet are not based on science," Dr. Peter Green, a co-author of the study and director of Columbia's Celiac Disease Center, told Reuters.

2. Skipping gluten is not necessarily better for overall health. About 1 percent of the population has celiac disease, and those folks need to avoid gluten because it causes inflammation in the small intestines and may lead to other health issues. About 10 percent of the population qualifies as gluten sensitive. But for the rest of the population, eating a gluten-free diet does not necessarily lead to improved health.

While some people may equate gluten-free with low-carb or carb-free diets, many gluten-free products contain added sugar and fat that stands in for gluten. And gluten-free products often lack the iron and essential vitamins than regular bread products contain, according to the Gluten Intolerance Group.

Eating a gluten-free diet can also affect one's digestive system, potentially causing bowel issues. “The most common issue people run into when starting a gluten-free diet is fiber intake often plummets,” Dr. Benjamin Lebwohl told The New York Times. Fiber is necessary in everyone's diet to ensure a healthy digestive tract.

3. Gluten-free diets may cause vitamin deficiencies. If you're avoiding gluten, for whatever reason, you may be at risk for vitamin and mineral deficiencies due to "both low intake and low absorption," the Gluten Intolerance Group says. The group lists thiamin, riboflavin, niacin, folate, iron, calcium and vitamin D as just a few of the nutrients for which you'll need to find other sources, either as food or supplements.

Gluten-free brownie mix on a supermarket shelf These gluten-free brownies, while delicious, would not be a better choice nutritionally than a piece of fresh fruit, which demonstrates why gluten-free food does not equal healthy food. (Photo: Michael Moloney/Shutterstock)

4. Dropping gluten does not necessarily equal losing weight. Lots of diets — Paleo, Atkins and South Beach, for example — encourage followers to go grain-free. So yes, if you cut out grains and carbs, you may lose weight. But there is no proof or guarantee that eating a gluten-free diet will help you shed unwanted pounds, according to the Cleveland Clinic.

"However, eating gluten-free often may cause you to eat more whole, unprocessed foods such as fruits, vegetables, legumes and lean meats. These diet changes are often healthier and lower in calories," the Cleveland Clinic says. "People eating gluten-free also tend to make healthier food choices because they are more aware of the need to read food labels. Ditching the double cheeseburger and fries for a gluten-free meal of salad, chicken breast, and sweet potato is choosing a meal that is much lower in calories. That can mean weight loss over time."

Plus, gluten-free food doesn't necessarily mean healthy food. The Cleveland Clinic uses an apple and a gluten-free cookie as an example. You can eat the gluten-free cookie, but it isn't a better nutritional choice than the apple.

5. Gluten isn't just about carbs. If you think gluten is limited to bread and other flour products, think again. Soy sauce, beer, candy, bottled marinades, some types of play-dough and even lip gloss can contain gluten, according to the Celiac Disease Foundation.

Angela Nelson ( @bostonangela ) is an exhausted mom of two young daughters and two old cats, and a Pulitzer Prize-winning digital editor with more than 15 years of experience delivering news and information to audiences worldwide.

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