Scientists have long known of a link between loss of smell and dementia — mainly because the plaque buildup that signals dementia initially occurs in parts of the brain related to memory and smell.
Now, researchers from Mass General Brigham have developed an innovative at-home smell test that could harness this knowledge to detect Alzheimer’s disease years before traditional symptoms emerge.
The study — published this week in the journal Scientific Reports — had English and Spanish speakers remember, identify and discern between various odors using peel-and-sniff cards.
The researchers determined that participants with cognitive impairment scored lower on these tests.
Since these tests were successfully completed at home, the findings could pave the way for an accessible, non-invasive and inexpensive method of early detection and subsequent preventative measures.
“Early detection of cognitive impairment could help us identify people who are at risk of Alzheimer’s disease and intervene years before memory symptoms begin,” lead study author Mark Albers, a neurologist at Massachusetts General Hospital, said in a statement.
“Our results suggest that olfactory testing could be used in clinical research settings in different languages and among older adults to predict neurodegenerative disease and development of clinical symptoms,” he added.
Alzheimer’s affects nearly 7 million Americans, a number that’s expected to grow to 13.9 million by 2060.
The condition is notoriously hard to diagnose, especially in its initial stages, because symptoms can be subtle and there isn’t a definitive test.
The Mass General study aligns with previous research exploring the potential of smell and memory tests in predicting cognitive decline.
Last year, researchers at Columbia University demonstrated that combining brief smell tests with short memory exams could signal dementia as effectively as costly brain imaging techniques.
New research has also uncovered the power of other senses for early detection.
A recent study showed loss of taste could signal neurodegenerative diseases such as Alzheimer’s.
Another recent study found that a simple vision test could detect dementia as early as 12 years before a diagnosis.
