–
Loss of smell is a common symptom of Covid-19. To fight against this symptom, which in addition to the sense of smell alters the perception of food in the mouth, daily training can help to recover the senses.
Some people infected with Covid-19 have a loss of smell, this is called anosmia. This symptom, associated for 85.9% of cases with a mild form of Covid-19, according to researchers from the University of Paris-Saclay, appears in the patient within a few hours.
During contamination, “the virus infects the olfactory mucosa which is located at the back of the nose where the olfactory receptors are”, explains Hirac Gurden, director of research in neuroscience at the CNRS in Paris. “At this location, the virus spreads quickly and can anchor itself on the olfactory mucosa and therefore destroy this structure and therefore the ability to detect odors”, explains the specialist. But the virus is not received the same by all patients. “The more cells of the olfactory mucosa express ACE2 proteins, the more likely the virus is to settle in this mucosa”. There is therefore genetic variability.
Once installed, the virus causes a certain threshold of infection and cell death in the mucosa. It is this reaction that causes the loss of smell.
A strong link between smell and taste
It can cause daily stress, but also food problems. Because the sense of smell plays on the sensation of taste. When we chew, odorous molecules are released in the mouth. These pass through an orifice at the back of the mouth and go up the nose via the retro-olfactory route. When you are anosmic, especially because of the coronavirus, this retro-olfactory pathway, essential to taste, no longer works.
Recovery time still uncertain
The recovery time varies depending on the infected people. “85% recover, at least partially, their sense of smell within three weeks after infection. For others, the time may be longer, ”reports the health professional. He finds that around 15% of those infected will not recover their sense of smell in the short term. It is still difficult to give an exact figure, because “little is known about the mechanisms of coronavirus infection and cell death in the olfactory mucosa”, warns the researcher.
A program to boost your olfactory sensations
Training remains the best solution to increase your chances of finding your “nose”. Doctor Hirac Gurden created, in connection with the association Anosmie.org, in 2019, a protocol to work on his sense of smell on a daily basis. “It has been shown in animal models that olfactory stimulation promotes the mechanism of neurogenesis in the olfactory mucosa”, explains the researcher before continuing “The more we train, the more this neurogenesis will be powerful and renew dead cells” .
This process of relearning odors is done “blind and if possible on an empty stomach”. Before carrying out the 12 to 16 week protocol, a first test to know if one is not allergic to the essential oils used in the protocol must be carried out. During a session, the protocol recommends placing the bottle of essential oil 2 centimeters from the nose and sweeping from right to left. You must then take the time to breathe at different rhythms and, calmly, “let perception come to you”, as described in the protocol.
Since the start of the Covid-19 pandemic, the number of downloads of this olfactory rehabilitation protocol has increased from a few hundred per month to several thousand, a sign of the enthusiasm and efficiency caused by this program.
–
