Within reach of an end to unnecessary bitterness?

About 3·2 million adults in the USA report a chronic chemosensory (gustatory and olfactory) problem, and the incidence of chemosensory disorders increases with age. 1 Hoffman HJ Ishii EK MacTurk RH Age-related changes in the prevalence of smell/taste problems among the United States Adult Populationxy. in: Murphy C Olfaction and Taste XII. vol. 855. Ann. NY Acad Sci, New York1998: 716-722 Google Scholar The number of people reporting an olfactory symptom is more than twice that for gustatory complaints. Olfactory disorders include those such as anosmia (complete loss of olfactory ability) and various types of olfactory dysfunction, such as dysosmias and hyposmias. True complete taste loss (ageusia) is very rare. More common are distortions of a taste, such as a decrease in the intensity of a given taste (hypogeusia) or a persistent taste in the mouth in the absence of stimulation (dysgeusia). There are few treatments for chemosensory disorders. The dysgeusias that lead to persistent negative tastes, such as sourness and bitterness, are the most annoying, and treatments to alleviate these would be especially useful.