Source: Ninz Embalsado/Pexels
Newly published research on the link between multisensory functions and cognitive decline among older adults suggests that experiencing a loss of smell may be an early indicator of dementia risk. This UCSF study (Brenowitz, Kaup, & Yaffe, 2020) was published on July 12 in Alzheimer's and Dementia: The Journal of the Alzheimer's Association.
"The olfactory bulb, which is critical for smell, is affected fairly early on in the course of the disease," first author Willa Brenowitz said in a news release. "It's thought that smell may be a preclinical indicator of dementia, while hearing and vision may have more of a role in promoting dementia." Brenowitz is a professor of psychiatry at the University of California, San Francisco and a core faculty member at UCSF's Center for Population Brain Health.
Before diving into the details of this study, it's important to note that beyond age-related cognitive decline, there are other reasons that someone may experience a loss of smell. For example, the CDC lists "new loss of taste or smell" as one of the symptoms associated with coronavirus disease 2019. That said, the just-published UCSF longitudinal study on a dementia-related link between vision, touch, hearing, and olfactory sensory functions was conducted over 10 years (prior to the COVID-19 pandemic).
For this decade-long study, Brenowitz and her UCSF colleagues recruited 1,794 older adults (aged 70 to 79). Study participants were given two different cognitive tests at the beginning of the study and every other year thereafter; they were also given multisensory tests to measure changes in vision, hearing, touch, and smell.
A "summary score" was used to evaluate the link between lower multisensory functions and faster rates of cognitive decline and dementia. Each participant's multisensory function score of 0 to 12 points was based on "sample quartiles of objectively measured vision, hearing, smell, and touch summed overall."
The researchers found that dementia risk was 2.05 times higher when the researchers compared "poor" to "good" multisensory score tertiles. Additionally, lower multisensory function scores were associated with faster rates of cognitive decline. Notably, study participants who could identify the distinctive scent of odors such as rose, lemon, or paint thinner were half as likely to develop dementia.
Among those with multisensory summary scores in the "good" range, only 12 percent developed dementia. On this continuum, 19 percent of participants with summary scores in the "middle" range developed dementia compared to 27 percent of people in with "poor" summary scores. Based on these findings, the authors conclude: "Worsening multisensory function, even at mild levels, was associated with accelerated cognitive aging."
While multisensory function summary scores appear to be a reliable indicator of someone's risk for incident dementia and faster rates of cognitive decline, the authors acknowledge that losing one's keen sense of smell appears to be the strongest indicator of remaining dementia risk. Participants whose olfactory ability declined by 10 percent had a 19 percent higher risk of dementia. Similar declines in vision, hearing, and touch were only associated with a 1-3 percent increase in dementia risk.
Of note, study participants who remained dementia-free tended to have higher cognitive scores and developed fewer sensory impairments. Again, on this continuum, those in the middle range tended to have multiple mild sensory impairments or a single moderate-to-severe impairment. Study participants with the highest risk of dementia and rapid cognitive decline had multiple moderate-to-severe sensory impairments.
"We found that with deteriorating multisensory functioning, the risk of cognitive decline increased in a dose-response manner," senior author Kristine Yaffe of UCSF's departments of Psychiatry and Behavioral Sciences, Epidemiology and Biostatistics, and Neurology concluded in the news release. "Even mild or moderate sensory impairments across multiple domains were associated with an increased risk of dementia, indicating that people with poor multisensory function are a high-risk population that could be targeted prior to dementia onset for intervention."
"smell" - Google News
July 21, 2020 at 11:34PM
https://ift.tt/3eP3Oyk
Why Being Able to “Smell the Roses” Matters as We Age - Psychology Today
"smell" - Google News
https://ift.tt/35zrwu1
https://ift.tt/3b8aPsv
Bagikan Berita Ini
0 Response to "Why Being Able to “Smell the Roses” Matters as We Age - Psychology Today"
Post a Comment