Is Kissing for Celiacs Gluten-Free? Small Study Weighs In

While people with celiac disease have a number of challenges in leading a gluten-free life, it appears kissing is not one of them.

In a prospective study of couples in which one partner had celiac disease, it was possible to transfer gluten through kissing, but it usually involved small amounts considered safe, reported Anne R. Lee, EdD, RDN, of the Celiac Disease Center at Columbia University in New York City, and colleagues in Gastroenterology.

Even in cases in which gluten levels in the saliva of partners with celiac disease exceeded 20 parts per million (ppm) — the threshold considered safe by FDA gluten-free labeling standards — they remained symptom free.

“And that was a big takeaway for us,” Lee told MedPage Today. “It’s a small sample, but based on these couples, [gluten transfer] was within the safe amount, no one had symptoms, and we feel we can reassure our patients that kissing is safe.”

To formally test whether there was a risk of transferring gluten through kissing, Lee and colleagues recruited 10 couples — one partner with celiac disease and one without. In either of two protocols, the non-celiac partner consumed a prescribed gluten load of 10 saltine crackers containing 590 mg of gluten, which was followed by open-mouth kissing with the partner with celiac for 1 minute.

In the first kissing protocol, the couple waited 5 minutes before kissing, while in the second protocol (conducted on a separate day), the non-celiac partner ate the crackers, drank 4 oz of water, and then immediately kissed the partner with celiac disease.

The researchers then tested the saliva of the partners with celiac disease, and followed that with urine tests for gluten immunogenic peptides.

Gluten was detectable in the saliva of the non-celiac partner in all protocols (80 ppm to >25,000 ppm), while the amount detected in the saliva of those with celiac varied from <5 ppm to 153.9 ppm.

However, only 2 of the 20 gluten exposures in the celiac partner tested over 20 ppm of gluten, the level defined as gluten free, and none of the saliva samples tested over 20 ppm when the non-celiac partner drank 4 oz of water after eating the gluten load.

Furthermore, the majority of saliva samples (60%) after drinking water contained no detectable gluten at all.

Kissing Concerns

The reaction to ingesting gluten can be extremely unpleasant for people with celiac disease.

“Anytime a person who has celiac disease ingests gluten, they very often have symptoms that can last a day or two,” Lee explained. “But, we have some people with neurological symptoms that can last a week, and it can cause damage in the gut. So, it increases the risk of other potential [gastrointestinal] issues down the road.”

“We see that with some of our patients there’s an increased anxiety, and almost a hypervigilance about maintaining a gluten-free diet,” she said, adding that the possibility of a chance gluten exposure exacerbates that anxiety, and could profoundly affect a person’s social and romantic life.

In a previous study, Lee and colleagues conducted an online survey of adults with celiac disease, which found that nearly 68% of 538 respondents said that the disease had a major or moderate impact on their dating life, while 39% said they were hesitant to kiss their partner because of it.

Lee and team pointed out that the internet is filled with recommendations — not backed by any evidence-based studies — on how to avoid gluten exposure when kissing. One site, for example, recommends that people with celiac disease practice “safe kissing” by carrying toothpaste, mouth wash, and floss with them on dates if they anticipate a kiss after a meal.

“I even had one patient whose husband had a beard, and she would make him go and take a shower to make sure there were no residual crumbs in his beard,” Lee said. “And that doesn’t bode well for spontaneity.”

“There’s just no science behind this, and we didn’t have the science to give good recommendations,” she added.

“The goal is for [people with celiac disease] to live life as normally as possible and preserve their [quality of life] and relationships,” Lee and colleagues concluded. “We can now inform patients about the quantitative risk of gluten exposure through kissing so that they can pursue relationships and intimacy without the fear of the unknown.”