THE ESSENTIAL
- The decrease in olfactory abilities appears around the age of 60 and is progressively accentuated.
- It is estimated that 10% of young adults suffer from olfactory disorders. The rate rises to 30% in those over 60 and to 83% in patients with Alzheimer’s.
Previous studies have shown that loss of smell is an early sign of cognitive decline. However, the ability to smell or not smell a perfume would not only highlight the aging of the brain. Difficulties in detecting and identifying an odor would also reveal an increased risk of frailty with age. This is what researchers at Johns Hopkins Medicine assure in a study, published on January 10, 2023, in the journal Journal of Gerontology.
Loss of sense of smell, a marker of frailty as you age
“We use our sense of smell to identify the threat of fire or to appreciate the scent of flowers on a spring day. But just like vision and hearing, this sense weakens with age”, explains Dr. Nicholas Rowan, associate professor of otolaryngology and author of the study. To verify the relationship between the frailty of seniors and the loss of smell, his team exposed 1,160 elderly people (average age 76) to 5 scents and asked them to identify them. The participants were also put in the presence of six other odors to measure their level of olfactory sensitivity. The scientists then measured the frailty score of the volunteers.
They found that for every one-point increase in identification and odor sensitivity scores, there was a significant reduction in frailty status. This implies that good olfactory performance was associated with improved health status. Conversely, the worse the sense of smell, the more fragile the participant. Thus, the loss of smell could be a measurable biomarker and a risk factor for frailty in the elderly.
An olfactory test to estimate the state of health of the elderly?
Given the results obtained during the experiment, Dr. Rowan believes that olfactory tests could be part of routine screenings to identify the risk of frailty and health concerns as you age.
“We already perform tests to assess our ability to see or hear, and it is just as easy to perform a simple smell test which only takes a few minutes. It could be used as a valuable tool to assess risk frailty or problematic ageing”says the expert. “For example, if someone misses a smell test, then maybe that patient needs to improve their diet or have a more detailed neurological or medical workup.”he concludes.
The scientist and his team are continuing their research to develop more detailed odor tests to help healthcare professionals better identify physiologically vulnerable elderly people.