This is Scientific American's 60-second Science, I'm Christopher Intagliata.
Memory loss and forgetfulness are common warning signs for dementia. But a dulling of the senses also appears to be associated with the disease.
"Smell is definitely the strongest one we found, but it does seem like it's not just smell."
Willa Brenowitz, an epidemiologist at the University of California, San Francisco. Her team studied cognitive decline in 1,800 adults from the Health, Aging and Body Composition Study—which tracked the health and mental function of older adults over a 17-year period.
During the study, the subjects completed sensory tests—including hearing, smell, touch and vision. Brenowitz's team tooked the results of those tests and then compared the adults' overall sensory abilities to their mental function. And the results?
"Those with better function had a lower risk of dementia. And with worse multiple sensory function, they had higher risk of dementia."
A decline in smell, in particular, had the strongest link to dementia. The results are in the Journal of the Alzheimer's Association: Alzheimer's & Dementia.
The scientists were just studying correlations here. But Brenowitz says if they can figure out how well multisensory decline predicts dementia risk, it might give doctors another tool to screen for the disease.
Thanks for listening for Scientific American's 60-second Science. I'm Christopher Intagliata.