Bitter tastes can be good for you. At least, tasting them can be. Bitterness taste receptors are found in the nose as well as the mouth, and those may be a first line defense against some types of bacterial infection, helping stop the bacteria almost the instant they get in.
Researchers say this is because the bacteria themselves are bitter-tasting. The receptors in the nose therefore function as a sort of early warning system, sounding an alert that activates the immune system as soon as an infectious agent reaches the body.
The primary use of the bitter sense along with sour, is to detect foods that are spoiled or otherwise toxic. This is less of an issue in an era of refrigeration and packaged foods, and scientists say one in four people is a “non-taster,” with a sharply limited ability to detect these bitter tastes, so foods like coffee and spinach—which should probably not be combined, but each of which is bitter on its own—don’t register as unpleasant. At the other end of the scale, a quarter of the population consists of “super-tasters” who are particularly sensitive to bitter flavors.
One of these bitter flavors is something called a biofilm, a sort of protective coating created by the bacteria responsible for sinusitis. The biofilm is in fact the direct instigator of sinusitis symptoms, which reflect an overenthusiastic immune reaction. That reaction is caused by the biofilm; however, when the bitterness receptors detect it, they call on immune cells that kill the invading bacteria before a biofilm has had a chance to form.
“Based on these findings, we believe that other bitter taste receptors in the airway perform the same ‘guard duty’ function for early detection of attack by different types of bacteria, and we hope to translate these findings into personalized diagnostics for patients with chronic rhinosinusitis,” said study author Noam Cohen, an otolaryngologist at the Philadelphia VA Medical Center, in a statement.
The researchers found that none of the super-tasters in their sample were infected with the bacteria. These super-tasters were able to taste it at significantly lower concentrations than other subjects.