(Reuters Health) - Often when someone in the family has celiac disease, two sets of kitchenware are used to avoid inadvertent exposures to gluten. But a new study suggests that may not be necessary.

In a series of experiments, researchers found that gluten-free bread doesn’t pick up the protein when it’s cooked in a toaster that’s recently been used with regular bread - even when there are crumbs in the bottom. Further, transfer of gluten from pots and pans can be avoided simply through washing them - or even just rinsing - after they’ve been used to cook regular pasta, according to the study published in Gastroenterology.

“Our team was shocked by the findings,” said lead author Vanessa Weisbrod, director of the Celiac Disease Program at Children’s National Hospital. “We expected to find higher levels and had to think long and hard about what we should conclude.”

Weisbrod was personally reassured by the findings. “I have celiac disease myself and my 6-year old son does, too,” she said. “Seeing this data made me feel a lot better about going out to eat with him and going to friends’ houses.”

In people with celiac disease, consumption of gluten, a protein in wheat, rye and barley, triggers an autoimmune response that damages the small intestine and interferes with absorption of nutrients.

Although the disease was once thought to be rare, experts currently estimate that there are more than 2 million people in the United States with the genetic disorder. That amounts to about 1 in 133 people, according to the National Institutes of Health.

Weisbrod and her colleagues tested the likelihood of gluten contamination in three common kitchen scenarios: toasting bread in a device that was recently used with gluten-containing bread, cooking gluten-free pasta in pans or water that were used to cook regular pasta, and cutting a gluten-free cupcake with a knife that had been used to cut gluten-containing deserts.

When the researchers toasted gluten-free bread in a toaster that had recently been used with regular bread, none of their samples contained more than 20 parts per million (ppm) of gluten, which is the amount the Food and Drug Administration requires for a food to be designated as gluten free.

For the pasta experiment, the researchers first tried cooking gluten-free pasta in water that had been previously used to cook regular pasta. In this case, there was contamination of the gluten-free pasta. However, rinsing the gluten-free pasta under running tap water reduced the contamination below 20ppm.

Next the researchers tried cooking gluten-free pasta in a pan that had been used with regular pasta. When the pan was washed, or even just rinsed, after being used for regular pasta, no detectable gluten contamination was found.

Similarly, when a knife was washed after being used to cut gluten-containing cupcakes it did not transfer the protein when used on gluten-free cupcakes.

Weisbrod has met with families who take their own pots and pans as carry-ons when traveling on planes. “Now they don’t have to,” she said.

The new findings will be “quite reassuring for patients, families and roommates since it shows that it doesn’t take that much to get rid of gluten,” said Dr. Joseph A. Murray, a professor of medicine at The Mayo Clinic and editor of Mayo Clinic’s “Going Gluten Free.”

“It’s not like peanuts and peanut allergy,” Murray said. “Accidental exposure to gluten is usually related to eating actual food with gluten in it.”

The new study is “important and helpful,” said Armin Alaedini, a long time celiac disease researcher and an assistant professor in the department of medicine and the Institute of Human Nutrition at Columbia University Medical Center.

“I think it should help reduce patient anxiety having to do with the very restrictive gluten-free diet needed for controlling celiac disease symptoms,” Alaedini said. “It indicates that the risk of biologically relevant gluten cross-contamination associated with common food preparation activities in the kitchen is low for celiac disease patients.”

Alaedini would, however, like to see the experiments performed in larger studies. He also notes that the FDA settled on the 20ppm designation because it was the lowest level that could be detected at that time.

“Recent data suggest that a concentration of 100ppm (for a daily total of about 30mg) of gluten can be tolerated by celiac patients,” Alaedini said.

SOURCE: bit.ly/2LNK3vY Gastroenterology, online September 24, 2019.