An Older Person’s Sense of Smell Can Predict Health Issues

Problems with a sense of smell may predict a higher risk for age-related health problems, according to researchers from the Department of Otolaryngology–Head and Neck Surgery, Johns Hopkins University School of Medicine.

What to Know

• Smell dysfunction acts as an early indicator of cognitive decline as well as signs of frailty in the brain and unhealthy aging.
• Researchers assessed olfactory sensitivity and olfactory identification, terms that denote the ability to detect an odor and the ability to detect and name an odor, respectively.
• As with vision and hearing, the sense of smell weakens as one ages.
• Impaired olfactory identification and sensitivity functions are associated with frailty, which is interesting because it shows that it’s not just the aging brain at work here. It may also be something peripheral, such as something involving the nose, that makes it possible to predict impending frailty and death.
• To measure identification skills, study participants were exposed to five scents; to measure sensitivity, they were exposed to six scents. These measures were then matched to their frailty scores.
• For each 1-point increase in both olfactory identification and sensitivity scores, frailty status declined significantly. This suggests that the ability to smell well has a connection to better overall health in the aging population.
• Impairment of the sense of smell may serve as an important biomarker and risk factor for frailty.
• Smell tests may become an integral aspect of clinical care for aging people who may be cognitively impaired. A simple smell test that takes only minutes and could potentially be a valuable tool to assess the risk of frailty or unhealthy aging.
• Failure to pass a smell test may indicate the need for the patient to improve their nutrition, or it may indicate the need of a more comprehensive neurologic or medical workup.
• Smell tests may be able to enhance clinical and research efforts for improving care for older adults, especially with COVID-19 affecting the smell of many patients around the world.

This is a summary of the article, “The Association of Peripheral and Central Olfaction With Frailty in Older Adults,” published in The Journal of Gerontology on January 10, 2023. The full article can be found on academic.oup.com.