Alessio Fasano has been an even busier man since he and 15 colleagues published a study in the journal BMC Medicine last March that showed it was possible to be sensitive to gluten—a protein in wheat, barley and rye, as well as in some soup and sauce thickeners—without having full-blown celiac disease. Athletes from around the world have contacted Fasano, the head of the University of Maryland Center for Celiac Research, for advice on how to limit their gluten intake. Pro cyclists had been seeking Fasano's help since 2008; now he makes three annual trips to Europe to consult with elite athletes in tennis, basketball, soccer, wrestling and swimming.
More and more athletes credit going gluten-free with boosting their energy. Some, such as U.S. distance runner Amy Yoder Begley (above), do it because they have celiac disease; others, including Saints quarterback Drew Brees and the world's top-ranked tennis player, Novak Djokovic, do it because they are gluten sensitive; and an intrepid few, including the Garmin-Transitions pro cycling team, do it because they are seeking a competitive edge. With gluten awareness on the rise because of the rapidly increasing number of people experiencing medical problems from ingesting the protein, gluten-free and gluten-light diets are not likely to join low-carb/high-protein (not to mention high-carb/low-protein) programs in the trash heap of athletes' eating trends.
While gluten can be a fine source of protein for most people, Fasano's research reveals that 6% of the U.S. population may be gluten sensitive, experiencing stomach pains, headaches or depression after ingesting the protein. Less prevalent (but still on the rise) is celiac disease, which causes the body's immune system to attack and inflame the intestines after ingestion of the protein.
Gluten, which was not a part of the human diet until people began cultivating wild grasses for food 10,000 years ago, cannot be fully broken down by enzymes in the body, even in people who aren't gluten sensitive. Consider this: According to Fasano, the digestive juices in your stomach are so corrosive to meat protein that if you dipped your finger in them, it would be down to the bone in 30 seconds—but the same juices can't polish off the gluten in a single crouton. "Some parts of gluten have the digestibility of a rock," says Chaitan Khosla, a Stanford professor of chemical engineering. "It just sits there, marking time, until it goes to the upper intestine."
The medical community is still not sure why some athletes feel a boost after eliminating gluten, but Fasano believes that it's because of gluten's protracted stay in the digestive tract: Blood that is needed in the extremities and in the brain gets diverted to the stomach to assist in the digestion of gluten, thereby diminishing the supply for energy and performance. Asked why the incidence of celiac disease has doubled in the last 15 years, Fasano says that wheat farmers have increasingly cultivated their crops to contain more (and possibly different) gluten to give food a pleasant taste and texture. "Your great grandfather's grains are not your grains," he says.
Yoder Begley, a U.S. Olympian in the 10,000 meters, travels with a reference book of restaurants that have gluten-free menus. To get the carbohydrates that her body needs to turn glucose into fuel for exercise, she eats carb-rich foods that aren't filled with fat or sugar, such as bananas, rice pasta, polenta and sweet potatoes. Her diet is a model for a burgeoning number of athletes. "All she knew to go after for carbs [without gluten] were things like potatoes and candy," says Krista Austin, a physiologist who helped tailor Yoder Begley's diet. "Nowadays almost every athlete I work with, whether recreational or professional, asks about gluten."