FRIDAY, July 19, 2013 (HealthDay News) -- Chances are you know at least one person who's given up eating gluten. Maybe you've even given it up yourself. But who can really benefit from a gluten-free diet?
"Gluten is one of the main proteins found in wheat, barley and rye," said Dr. Joseph Levy, division director of pediatric gastroenterology at NYU Langone Medical Center in New York City. "It's actually a group of proteins and not a single component, but gluten is the general term."
In baking, it plays a key role. "Gluten is responsible for the way dough is able to rise when you put yeast in it," Levy explained. "It's the structure of gluten that makes baked goods light and crispy. If you try to cook with gluten-free flour it won't have the same airiness. The dough is heavier, and the finished product will be flat and heavy."
But though gluten might make for a flaky croissant, it can cause a number of problems for certain people.
Registered dietician Rachel Begun, a spokeswoman for the Academy of Nutrition and Dietetics, said that three types of people may not be able to eat products containing gluten: people with celiac disease, people with gluten sensitivity or intolerance, and people with a wheat allergy.
"Celiac disease is an autoimmune disorder, and when gluten is eaten, the body triggers an attack on the intestines," Begun said. "Damage occurs over time, and nutrients can't be absorbed."
Levy said that "even tiny amounts of gluten trigger an immune-mediated attack on the lining of the bowel." For someone with celiac disease, "it's important that you don't have any exposure to gluten," he said.
One problem, though, is that people aren't always aware that they have celiac disease. In fact, a study published last year in the American Journal of Gastroenterology found that almost 80 percent of people with celiac disease don't know they have it.
Celiac disease often has no symptoms for years, Begun said, and is often discovered because of the problems it creates, such as anemia or osteoporosis.
Another group of people who might benefit from forgoing gluten are those who have what's called gluten sensitivity. "We're just starting to recognize this non-celiac-related sensitivity to gluten," Levy said.
"When they eat gluten," he said, "they can have diarrhea or they may get bloated, nauseous, tired and achy." Begun added that people who are gluten-sensitive may also experience migraines and feel like they have a "foggy brain."
"Something is going on in the body that triggers these symptoms, but you don't see damage to the intestine," she said. "There's a lot of research going on now in this area, but we don't yet know if there are any long-term consequences of gluten sensitivity."
Others who might want to avoid gluten are those who are allergic to wheat. Begun said while there's no specific allergy to gluten, some people with a wheat allergy choose to avoid gluten-containing products altogether due to the risk of cross-contamination with wheat.
Though it might seem logical to stop eating gluten to see if it's at the root of your problems, both Levy and Begun noted that that's an extremely bad idea. First, they said, you should see a gastroenterologist to be evaluated for celiac disease. Otherwise, stopping consumption of gluten can mask the true cause of your symptoms.
Once those results are in, dietary adjustments can follow. Begun said the best gluten-free diet is one that contains foods that are naturally gluten-free, such as fruits, vegetables, low-fat dairy, beans, nuts, seeds, fish and lean meats.
"A healthy diet really doesn't need to change much when you give up gluten," she said. But people with celiac disease need to carefully watch for hidden sources of gluten. For example, she said, bottled salad dressings may contain gluten, as might soy sauce, medications, vitamins and even lip balm.
"For people with celiac disease, it's not just a matter of trying to avoid gluten," Begun said. "They must avoid even tiny amounts of gluten."
Eating out gluten-free can be a challenge because restaurants don't always understand that cross-contamination can be a problem, too. "If a gluten-free food touches something with gluten, someone with celiac can't eat it," Begun said. "The restaurant industry as a whole is trying hard and has come a long way."
Friends and family can sometimes be more of an issue for someone with celiac disease. "There's a lack of understanding about the need to avoid gluten 100 percent of the time," she said.
But if you don't have celiac disease -- which affects about 2 million people in the United States, according to the U.S. National Institutes of Health -- there should be no harm in trying a gluten-free diet, Levy said, assuming that you've seen a doctor if you suspect celiac.
He said you can get all the nutrition you need from a gluten-free diet. But, he added a note of caution for those who eat gluten-free with the hope of losing weight.
"People who go on gluten-free diets tend to gain weight," Levy said. "People often substitute gluten-free flours and alternative baked goods, and too much of these foods can increase weight."
The American Gastroenterological Association has more about celiac disease and a gluten-free diet.
To read about one woman's experience with a gluten-free diet click here.