Smell loss may help predict frailty and unhealthy aging

Credit: Unsplash+

In a study from Johns Hopkins Medicine, scientists found that loss of the sense of smell is a predictive marker for an increased risk of frailty as people age.

Previous research has found that olfactory dysfunction is a common early sign of brain-linked cognitive decline.

The new findings suggest the link to frailty is likely not just in the brain but also in the nose itself.

If further studies affirm the findings, screening older adults’ ability to smell various scents could be as important as testing hearing and vision over time.

In the study, the team examined nearly 1200 older people and looked at the prevalence of frailty, an age-related syndrome of physiological decline, along with two different ways of assessing the ability to smell:

Olfactory sensitivity (the ability to detect an odor’s presence) and olfactory identification (the ability to detect and name an odor).

They used a standard assessment of frailty (called a Physical Frailty Phenotype, or PFP, score) that looks at five markers: weight loss, exhaustion, weakness, slow walking speed and low physical activity.

Olfactory identification is a central measure of smell function, which has been linked to frailty and relies on higher-order cognitive processing to interpret and classify an odor.

This suggests that neurological function may help to explain the relationship between smell and frailty.

However, researchers say the ability to merely detect an odor without having to use higher-level neurological processes and the relationship of the ability to detect odors alone with frailty have been understudied.

The team says that although these findings in older adults add to a body of literature that suggests the sense of smell can be a bellwether of frailty and impending mortality, the link of these unique sensory losses with unhealthy aging over time is unclear.

What is clear is that common consequences of smell loss include a loss of appetite, difficulty monitoring personal hygiene, depression, and an inability to detect toxic fumes.

In older adults, this may be associated with weight loss, malnutrition, weakness, inadequate personal care and even potential injuries caused by gas leaks or fires.

If you care about pain, please read studies about vitamin K deficiency linked to hip fractures in old people, and these vitamins could help reduce bone fracture risk.

For more information about wellness, please see recent studies that Krill oil could improve muscle health in older people, and Jarlsberg cheese could help prevent bone thinning disease.

The study was conducted by Nicholas Rowan et al and published in The Journals of Gerontology: Series A.

Copyright © 2023 Knowridge Science Report. All rights reserved.