Scientists warn that an abrupt loss of smell, which has become a characteristic of Covid, may also be an early indicator of dementia.
Prior research has linked the gradual loss of olfactory sense to the memory-eroding illness.
New research suggests, however, that a quick decline may be a stronger indicator.
Over the course of around 20 years, researchers in the United States observed over 500 elderly individuals.
Those who lost their sense of smell over several years were nearly twice as likely to acquire Alzheimer’s as those who lost their sense of smell over decades.
The study’s senior author, Professor Jayant Pinto of the University of Chicago, stated that it “provides another clue” regarding the relationship between odor and dementia.
To screen for the condition, he advised making smell tests as regular as hearing and vision examinations for seniors.
Although the sense of smell is commonly seen as less significant than sight and hearing, it offers vital information to the brain.
Memory is crucial for the capacity to identify odors, and researchers have long recognized a connection between this sense and cognitive decline.
According to studies, ‘tangles’ of the protein amyloid in the brain — a telltale indicator of dementia — frequently emerge first in regions of the brain related to olfaction and memory.
However, it is still unknown if this damage is responsible for the reduction in a person’s sense of smell.
Professor Pinto and his team wished to determine whether these changes link with the progressive loss of olfactory and cognitive abilities.
The study’s lead author, a university researcher named Rachel Pacyna, stated, ‘We hypothesized that people with a rapidly declining sense of smell over time would be in worse health — and more likely to have brain problems and even Alzheimer’s — than those with a slowly declining or normal sense of smell.
Twenty years were spent observing 515 individuals in their seventies who did not initially have dementia or cognitive difficulties.
All of the volunteers resided in retirement communities and were evaluated annually on their ability to recognize various odors and dementia symptoms. Some also had MRI scans.
The loss in their sense of smell was determined by their olfactory test scores, which were then shown on a graph. The slope’s downward tendency was rated as “severe,” “decreased,” “unchanged,” or “better.”
Approximately one hundred members of the cohort were later diagnosed with dementia or cognitive impairment.
Those with no conventional Alzheimer’s symptoms but a rapid reduction in their sense of smell were 89 percent more likely to acquire memory-robbing diseases than those with a slower decline in their sense of smell.
A rapid drop in the sense of smell was also associated with an increased chance of having less grey matter in areas of the brain associated with scent and memory, compared to individuals with a slower decline.
The changes were especially noticeable in the amygdala and entorhinal cortex, which are responsible for smelling.
Their risk was comparable to that of individuals with the APOE-e4 gene, a known genetic risk factor for Alzheimer’s disease.
One in four individuals with the gene is three times more likely to develop Alzheimer’s than those without the gene.
To broaden their findings, the researchers plan to someday do autopsies on the volunteers, which is the gold standard for determining whether a person has Alzheimer’s.
In addition, they wish to investigate the use of smell tests in clinics for older persons, comparable to vision and hearing exams, to detect and monitor early signs of dementia. GOOD
According to them, fragrance tests are inexpensive, simple to use, and entail smelling a series of sticks that resemble felt-tip pens.
Each stick is imbued with a unique scent, which individuals must identify from a list of four options.
Ms. Pacyna stated, “If we could identify folks in their 40s, 50s, and 60s who are at a higher risk earlier, we might potentially enroll them in clinical trials and provide better drugs.”
The team highlighted that just one-fifth of patients received MRI scans, and those who did had only one, thus they lacked the data necessary to determine when structural brain abnormalities first occurred.
And because the majority of participants were white, additional research is required to determine if other populations are similarly affected.
Loss or alteration of the sense of smell or taste was one of the three primary symptoms of Covid first discovered by health officials last year as the virus swept the world.
As the virus has changed and new strains have taken root, however, many afflicted individuals no longer report altered perceptions.
WHAT IS DEMENTIA? THE KILLER DISEASE THAT ROBS SUFFERERS OF THEIR MEMORIES.
A GLOBAL CONCERN
Dementia is an umbrella term for a variety of degenerative neurological conditions (those affecting the brain) that affect memory, cognition, and behavior.
There are numerous varieties of dementia, with Alzheimer’s disease being the most prevalent.
Some individuals may have multiple types of dementia.
Regardless of the type diagnosed, each individual will uniquely suffer from dementia.
Dementia is a worldwide concern, although it is particularly prevalent in nations where individuals are more likely to live to a ripe old age.
WHAT NUMBER OF PEOPLE ARE AFFECTED?
According to the Alzheimer’s Society, there are currently over 900,000 persons living with dementia in the United Kingdom. This is expected to increase to 1,600,000 by 2040.
Alzheimer’s disease is the most prevalent form of dementia, affecting 50 to 75% of people who are diagnosed.
It is believed that there are 6 million Alzheimer’s patients in the United States. A similar percentage increase is anticipated over the next few years.
As a person ages, their risk of having dementia also increases.
It is believed that many individuals with dementia remain undetected, even though dementia diagnostic rates are increasing.
IS A CURE AVAILABLE?
There is currently no cure for dementia.
However, new medications can reduce its spread, and the earlier it is detected, the more effective the treatment.
