If you have celiac disease, a kiss can just be a kiss without worry about gluten

Evidence shows there’s little chance of getting exposed to gluten through a kiss, a study presented at DDW found

By Amy Ratner, director of scientific affairs

If you have celiac disease, get ready to pucker up without fear that kissing will expose you to gluten.

A new study by researchers at Columbia University found that there is little risk of getting cross-contaminated by gluten through kissing.

Why the worry?

In 2021, a survey also done by the Columbia researchers showed that among about 600 participants with celiac disease about 40 percent indicated they were hesitant to kiss. Women were more hesitant than men to kiss because of celiac disease and the worry that they might pick up gluten cross-contact from kissing.

Also, worry about kissing caused increased social anxiety. Researchers concluded that the risk of transferring gluten while kissing needed to be explored.

And explore it they did by recruiting 10 couples, with one person in each who had celiac disease and the other who did not. The study was designed to determine how much gluten might be transferred in saliva and whether kissing the partner who had eaten gluten would trigger symptoms in the celiac partner.

The partner who did not have celiac disease ate 10 crackers with a total of nearly 60,000 parts per million of gluten.

Some serious kissing then ensued. Couples had to smooch with an open mouth for at least one minute, involving the tongue and transferring saliva. For reference, foods that contain 20 parts per million gluten or more are not considered safe on the gluten-free diet.

How kissing was tested

For the first test, the couples waited five minutes after the gluten was eaten before kissing. For the second, the partner who did not have celiac disease consumed the gluten, then drank 4 ounces of water before the kissing commenced.

Saliva was collected from the partner who had celiac disease immediately after the kiss and was tested for gluten content.

Additionally, a test for gluten in the urine of the person with celiac disease was done the evening of the kiss and the following morning.

Gluten was detectable in the saliva of both kissers. Most of the partners who had celiac disease had less than 5 ppm of gluten in their saliva, though two exposures had more than 20 ppm, including one with about 154 ppm after a kiss that came five minutes after the partner ate the crackers.

The partners who did not have celiac disease and ate the gluten containing crackers had a range of gluten from 19 ppm to more than 2500 ppm in their saliva, but when they drank 4 ounces of water before kissing, the amount of gluten in the saliva of the partner with celiac disease was always less than 20 ppm.

There was only one positive gluten urine test from the person with celiac disease whose saliva contained the highest amount of gluten. No symptoms were reported post kiss by any of the study kissers who had celiac disease.

“Though gluten is detectable in saliva after ingestion, there is not an increased risk of significant cross-contact when kissing someone who has consumed gluten,” the study concludes, while noting that kissers can help their celiac disease partners by drinking water after a gluten binge.

Of note, the highest gluten content was found in a couple who had just gotten engaged the previous night, which might explain a lot.

The study shows that there is a minimal risk of gluten transfer in saliva, said Ann Lee, PhD, of the Celiac Center at Columbia University and a lead study author. As an added precaution you could ask your gluten-consuming partner to have a drink of water before moving in for a kiss.

“The biggest upshot of the study is not to let your anxiety over cross contact interfere with your romantic life,” Lee concluded.

DDW is the largest international gathering of physicians, researchers and academics in the fields of gastroenterology, hepatology, endoscopy and gastrointestinal surgery. Studies presented at DDW are sometimes preliminary and give an early look at investigations that are likely to include more details as they progress toward publication in a peer reviewed scientific journal.