Smell and health
Loss of smell became a hot topic during the COVID-19 pandemic: it turned out to be one of the specific symptoms of infection that can persist for many months. At the same time, impaired sense of smell has always been a significant medical problem. It is well known that it is common in the elderly.
Poor sense of smell is often associated with the risk of death and neurodegenerative diseases (dementia, Parkinson’s disease). These two diseases account for 22% of excess mortality among older people with a weak sense of smell. However, approximately 70% of early deaths in this group of people remain unexplained.
Poor sense of smell is a risk factor for pneumonia
In a new study, the researchers decided to test the hypothesis whether a low sense of smell is a risk factor for developing pneumonia. Potentially, this link can be explained by the fact that the nasal mucosa is very important for protecting against infections. Loss of smell can be a marker of damage not only to olfactory receptors, but also to mucous membranes in general.
“About a quarter of people over 65 complain of a bad sense of smell. Unlike visual and hearing impairments, this problem is often ignored. More than two-thirds of people with a poor sense of smell don’t even realize it, ”said Honglei Chen, a professor at Michigan State University and co-author of the new study.
Scientists analyzed data from a 13-year observation of 2,500 people aged 71-82 years. At the beginning of the study, all of them underwent a test for acuity of smell, in which they use common smells – lemon, gasoline and others. The authors then monitored how often study participants were hospitalized for pneumonia.
It turned out that people with a weak sense of smell are hospitalized with pneumonia 50% more often than those who can smell well. In people of this group, who had not previously had pneumonia, the risk of getting sick for the first time was 40% higher.
Scientists note that this is likely the first study to demonstrate a link between poor sense of smell and pneumonia.
“This is just one example of how much we don’t know about a common violation,” Chen said.