Ageusia: the complete loss of the sense of taste....more
Dysgeusia: distortion or partial loss of the sense of taste....more
Olfaction: a way of sensing the environment using chemicals. In humans, olfaction is the sense of smell.
Olfactory: relating to the sense of smell.
Otolaryngologist: a doctor that specializes in the ear, nose, throat, head and neck.
Threshold: the point at which something changes; usually the point at which a stimulus is large enough to produce an effect.
Even the most delicious food is left unappreciated if there is a problem with the taste system. Nearly everyone can relate to the reduced sense of taste that occurs during a cold or flu. Congestion in the nasal cavity often clogs the special pathway that connects the mouth to the nose. That pathway is important for the full flavor experience.
Temporary taste disturbances, termed disgeusia, that result from illness or injury generally improve once you get better. Sometimes, however, the cause for a taste disturbance is not so easy to identify or fix. When a person has a reduced sense of taste, there is often a problem with other senses as well, especially olfaction, since the two senses interact a lot.
Diagnosis of disgeusia, or the more extreme ageusia, which is the complete lack of taste, is done by a special doctor. Otolaryngologists specialize in the ear, nose, throat, head and neck. The doctor will typically perform gustatory testing, in which different solutions – sweet, sour, salty, and bitter – are given to the patient. The lowest concentration of these tastes that someone can identify, called the taste threshold, is determined, and compared to the average level.
Taste disturbances can result from any condition that alters the functioning of taste receptors, the taste-carrying nerves, or the regions of the brain that process the taste signal.
As people age, the sense of taste, along with most of the other senses, begins to get worse. The average person is born with about 9,000 taste buds, which normally replace themselves every 1-2 weeks. This replacement process, however, appears to slow as we age. In addition to the aging of the olfactory system, and the increased use of medications among older people that can interfere with taste, this means that taste fades with age. Altered taste becomes noticeable around age 40, and often happens earlier in women than in men. While we can work to improve the flavor experience by seeking out spicy, bold flavors with enjoyable textures, this is just part of the normal aging process.
Additional images via Wikimedia Commons. Millet dish by Jennifer from Vancouver.
Shelley Valle. (2017, October 06). Problems with Taste. ASU - Ask A Biologist. Retrieved September 25, 2020 from https://askabiologist.asu.edu/fr/node/4061
Shelley Valle. "Problems with Taste". ASU - Ask A Biologist. 06 October, 2017. https://askabiologist.asu.edu/fr/node/4061
Shelley Valle. "Problems with Taste". ASU - Ask A Biologist. 06 Oct 2017. ASU - Ask A Biologist, Web. 25 Sep 2020. https://askabiologist.asu.edu/fr/node/4061
What would life be like if you lost your sense of taste?