Millions of individuals suffered with a lack of scent when the SARS-CoV-2 virus, which caused COVID-19, spread over the world. People who have temporarily lost their sense of smell often regain it over time. However, this isn’t true for everyone. A new meta-analysis of 18 research reveals that around 5.6% of persons with post-COVID-19 smell loss (or the closely associated taste loss) are still unable to smell or taste properly six months later. The figure, published in the British Medical Journal on July 30, seemed low. Yet the numbers become significant when you think about the 550 million COVID-19 instances and counting that have been reported so far.
Researchers are looking for treatments to speed up the recovery process for the sense of smell. After three years, scientists have a clearer picture of how many individuals have been impacted by the COVID-19 epidemic and how long it seems to endure. However, current scientific research on methods to wire up the sense of smell isn’t promising.
Smell training, also known as olfactory training, has demonstrated some positive results, but its mechanisms and potential beneficiaries are still little understood. The coronavirus isn’t the first disease to steal scent, and the technology has been known for some time. More attention is being paid to olfactory training and other relatively new therapies because of the advocacy efforts of those with COVID-19.
A person’s sense of smell is often overlooked in favor of their other senses, such as sight and hearing. However, the consequences of losing it might be severe.
Smell-detecting cells, unlike their counterparts for seeing and hearing, are capable of self-renewal. The nose’s stem cells are constantly cranking out new olfactory receptor cells. Olfactory sensory neurons are covered in molecular nets that trap individual odor molecules as they drift into the nose. The brain receives signals from these cells after they have been engaged.
The mechanism by which SARS-CoV-2 impairs the sense of smell is unclear. New evidence suggests, however, that the virus may be attacking in a roundabout way. Viruses may infect and destroy sustentacular cells in the nose. These cells are considered to play a role in keeping olfactory neurons healthy by supplying them with glucose and regulating their salt balance. The olfactory epithelium, which lines the nasal cavity, may become inflamed in response to such an assault.
How to train your nose
Smell training is one of the few treatments that are now available, and it consists of nothing more than a straightforward exercise for the nose. It requires concentrating on the smell of four different fragrances (often rose, eucalyptus, lemon, and cloves) for thirty seconds each, twice a day for a period of months. In one research, 40 persons who had smell problems participated in the training, and at the end of it, they had increased their ability to smell, on average, compared to 16 people who did not participate in the training.
Since then, the majority of studies that have been conducted have shown that the technique is effective for between 30 and 60 percent of the individuals who attempt it. One of the reassuring aspects is that there are no unintended negative consequences. However, self-discipline and endurance are required to complete the exercise in the proper manner. It is pointless to try to achieve this if you don’t do it consistently and you quit up after just 14 days.
It is not understood how the method works in the individuals that it seems to aid; yet, it appears to be beneficial. It is possible that it draws people’s attention to odors that are not very strong; it is also possible that it stimulates the creation of replacement cells; and it is also possible that it strengthens specific circuits in the brain. This kind of training has been shown to boost the number of smell sensory neurons in other species.