You might not relish the ability to taste the bitter compounds that give Brussels sprouts and kale their good-for-you flavors. But for those with chronic sinusitis, it might be a good sign.
In a new study from the Monell Chemical Senses Center and the University of Pennsylvania, researchers found that patients showed greater improvement after surgery if they had a working version of a specific type of bitter taste receptor.
Danielle Reed, a scientist at the Monell Chemical Senses Center and an author of the work, said some people have differences in their receptor genes, and are unable to taste certain bitter compounds. The receptors are on the tongue, but also throughout the body in mucosal surfaces, including the nasal passages.
“It’s a bit like being color blind, except it’s taste blind for specific keys that bind the locks that are those receptors,” she said.
The results suggest that one day, a taste test prior to surgery might be used to help manage expectations.
“We can use that to tell our patients that, ‘Look, you’re a great candidate,’ or ‘Look, you’re going to do better but you’re still going to have some issues down the road,'” said Noam Cohen, a head and neck surgeon at Penn and co-author of the work.
More than 35 million Americans suffer from chronic sinusitis, a condition Cohen describes as a severe head cold that “never seems to go away.” Many patients can get by with medical therapy, but some need surgery, and about a quarter will still struggle to control symptoms following the procedure.
In the study, published in the International Forum of Allergy & Rhinology, the scientists genotyped surgical patients for the specific bitter taste receptor and asked them to rate symptoms before and after surgery with a 22-question questionnaire (appropriately named SNOT-22). In people with sinusitis without polyps, those with two functional copies of the gene improved their scores about three times as much as those with one or zero copies.
Some people with a single functional gene produce a lot of working receptor, and can taste bitter flavors well, noted Cohen. For that reason, he suspects a taste test will actually be more predictive than the genetics. But it’s also possible that the test could fail if varying tissues express the receptor differently.
“One of the things we need to check is whether the tongue matches the nose,” said Reed. “And it might not.”
The researchers cautioned that the number of patients was small, and the work should be replicated in a larger population. There was no relationship between taste receptor genes and outcomes in patients with polyps, so taste tests are not likely to be helpful for roughly half of all sinusitis sufferers.
It’s also not yet entirely clear why non-tasters don’t do as well after surgery, but the group has previously found that the bitter taste receptors play an important role in the nose, where they detect bacteria and trigger cells to fight off infections.
“They just might be able to get over that initial surgical insult and do much better and heal their cavity,” said Cohen, “rather than a non-taster, who’s got a weakness in their ability to defend against bacteria.”