This work built on previous NIA research, which had shown that one of the known COVID-19 virus receptors is also present on taste bud receptor cells. They also found that taste bud basal cells - which produce new taste buds as old ones die off - affected by the virus produced buds that were smaller, misshapen, and had fewer taste receptor cells than healthy ones. The team examined biopsy samples, discovering that low amounts of virus, undetectable by COVID polymerase chain reaction (PCR) tests, lingered in tongue and taste bud cells in some cases for as long as 1.5 years. To understand why some people experience persistent loss of taste, a team of NIA scientists looked at 16 people who had recovered from COVID-19 and still lacked a sense of taste six weeks after a negative COVID nasal swab test. A recent study estimated that 60% of people infected with COVID in 2021 lost some ability to taste or smell, and a quarter of those patients, approximately 28 million Americans, didn’t fully recover and were left with a decreased sense of smell.
COVID-related loss of smell and taste affects millions of people, can negatively alter overall quality of life and nutrition, and lead to depression.
