Losing your sense of smell can be one of the earliest signs that you’re developing dementia, according to a new study.
The memory-robbing illness, which affects the lives of millions, causes problems with memory, language and mood.
But changes to our senses—which occur years before the devastating illness is formally diagnosed and appear to be unconnected—could be a key warning sign we are developing the life-shattering disease.
The German researchers found that this is because the immune system attacks vital nerve fibres linked to detecting scent.
The team looked at mice, as well as PET brain scans in living patients and post-mortem tissues from Alzheimer’s patients.
In mice, they found early damage to the nerve fibres that link the olfactory bulb—the brain’s scent hub—to the locus coeruleus that aids sensory processing.
Then the PET scans confirmed the same pathway observed in the rodents was disrupted in living human patients.
Furthermore, the brain tissue samples from deceased Alzheimer’s patients revealed the chemical changes that trick the immune system into destroying the fibres.
The fresh study suggests loss of sense of smell could be one of the earliest signs of dementia
The scientists say these consistent findings, which were published in the journal Nature Communications, strongly show that losing your sense of smell is an early sign of the illness.
Dr. Jochen Herms of the University of Munich said: ‘Our findings could pave the way for earlier identification of patients at risk of developing Alzheimer’s.’
This, he explained could ‘enable them to undergo comprehensive testing to confirm the diagnosis before cognitive problems arise. This would allow earlier intervention’.
An early diagnosis for dementia is considered critical, as while the condition is incurable, treatments can combat symptoms and sometimes slow progression.
Previously, other researchers found changes in sight, hearing, taste, touch and balance also strike years before more well-known symptoms.
Experts have also warned that problems with spatial awareness—for instance, standing too close to people—are also potential dementia warning signs which can occur up to twenty years before typical symptoms.
Classic symptoms of dementia include issues with memory, thinking speed, mental sharpness and quickness, language, understanding, judgement and mood.
More than 944,000 people in the UK are thought to be living with dementia, while the figure is thought to be around seven million in the US.
Recent analysis by the Alzheimer’s Society estimated the overall annual cost of dementia to the UK is £42billion a year, with families bearing the brunt.
An ageing population means these costs—which include the lost earnings of unpaid carers—are set to soar to £90billion in the next 15 years.
Analysis by Alzheimer’s Research UK found 74,261 people died from dementia in 2022 compared with 69,178 a year earlier, making it the country’s biggest killer
The fresh findings follow research published just days ago that revealed a sense of purpose can lower your risk of developing dementia.
American scientists who published their findings in The American Journal of Geriatric Psychiatry followed more than 13,000 adults aged 45 and older for up to 15 years.
They found people with ah higher sense of purpose in life were 8 per cent less likely to develop cognitive impairment—including dementia.
This protective effect was seen even when factors like race, ethnicity, education, genetics and depression are taken into account.
‘Our findings show that having a sense of purpose helps the brain stay resilient with age,’ said Aliza Wingo, lead author of the study, and professor at UC Davis.
‘Even for people with a genetic risk for Alzheimer’s disease, sense of purpose was linked to a later onset and lower likelihood of developing dementia’.
They also found those with higher purpose experienced cognitive decline on average 1.4 months later than those without it.
Source link
