In a study using data from nearly 1,200 older adults, Johns Hopkins Medicine researchers have added to a growing body of evidence that loss of the sense of smell is a predictive marker for an increased risk of frailty as people age. Building on previous research showing 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, the researchers say, screening older adults’ ability to smell various scents could be as important as testing hearing and vision over time.
Results of the study, published Jan. 10 in the Journal of Gerontology, 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). 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.