Dementia: Losing your sense of smell could be linked to having Alzheimer's, scientists suggest

Losing your sense of smell could be a symptom of dementia, according to new research.

A study carried out by the University of Chicago suggests that a person's sense of smell disappearing can be linked to a cognative decline - forecasting that Alzheimer's and dementia could be on the horizon.

The findings, based on a longitudinal study of 515 older adults, could lead to the development of smell-test screening to detect cognitive impairment earlier in patients.

Jayant M. Pinto, a professor of surgery at the University of Chicago, said: "This study provides another clue to how a rapid decline in the sense of smell is a really good indicator of what's going to end up structurally occurring in specific regions of the brain.

"We were able to show that the volume and shape of grey matter in olfactory and memory-associated areas of the brains of people with rapid decline in their sense of smell were smaller compared to people who had less severe olfactory decline."

Scientists found that a rapid decline in a person’s sense of smell during a period of normal cognition predicted multiple features of Alzheimer’s disease, including smaller gray matter volume in the areas of the brain related to smell and memory, worse cognition and higher risk of dementia in these older adults.

Medical student and lead author Rachel Pacyna added: "Our idea was that people with a rapidly declining sense of smell over time would be in worse shape – and more likely to have brain problems and even Alzheimer's itself – than people who were slowly declining or maintaining a normal sense of smell.

"If we could identify people in their 40s, 50s and 60s who are at higher risk early on, we could potentially have enough information to enroll them into clinical trials and develop better medications."