Dementia hits clever people harder, study finds
The neurodegenerative disease is the leading cause of death in the UK and is caused by certain proteins clumping together in the brain
Dementia claims the lives of smarter people sooner, scientists have discovered.
People who spend more years at school or in education are likely to deteriorate from the neurodegenerative disease faster, according to the biggest study of its kind.
Scientists have dubbed the phenomenon the “cognitive reserve paradigm”.
A person’s cognitive reserve is their brain’s ability to cope and keep working, including in the face of diseases such as dementia and Alzheimer’s.
It can be bolstered through learning and mental stimulation such as education and doing brain puzzles.
But the research found that, paradoxically, these patients go downhill faster if they do get a diagnosis.
Research published in the BMJ, which analysed 261 studies including 36 relating to educational attainment, found life expectancy after a dementia diagnosis decreased for every extra year of education a person had received.
The average survival time was 10.5 years, but the scientists calculated that for every extra year of study a person had undertaken, they lived for 0.2 years less – equivalent to about two and a half months.
It would mean someone who had finished an undergraduate degree aged 21 would live for a year less than someone who left school after their GCSEs or O-Levels.
Experts believe it is because people of higher intelligence are more resilient to cognitive decline and able to function for longer without signs or symptoms of the disease onsetting.
This often means they are diagnosed with dementia at a more advanced stage, making it harder to treat or slow down. As a result, they are likely to have fewer years to live compared to those diagnosed earlier.
‘More resilient to brain injury’
Authors from the Erasmus University Medical Centre, in Rotterdam, Netherlands, said: “This paradigm postulates that people with higher education are more resilient to brain injury before functional declines.
“Once this reserve has been used up and dementia is diagnosed, however, these people are already at a more advanced stage of the underlying disease and clinical progression will be faster.”
Dementia is the leading cause of death in the UK and there are various types with differing symptoms, impact and rates of decline.
The condition is caused by certain proteins clumping together in the brain, including amyloid and tau, which new drugs are trying to stop from occurring.
Many brilliant minds have been hit by dementia, although there is limited information on affected individuals in the public domain.
Among them, however, was Sir Terry Pratchett, the British author, who passed away at 66 after being diagnosed with a rare form of Alzheimer’s disease called posterior cortical atrophy.
Dame Iris Murdoch, the novelist and winner of the Booker Prize and Whitbread Prize, died in 1999 aged 79. She had been diagnosed with Alzheimer’s disease in the mid-1990s.
Robin Williams, the Oscar-winning actor, died by suicide after the rapid onset of Lewy body dementia, which significantly affected the quality of his life and was only diagnosed after his death.
This week award-winning BBC musician Lorna Spode died aged 98 after a battle with dementia that had only onset since the pandemic.
Despite the BMJ findings, research has found that the more education a person has the less likely it is they will be diagnosed with dementia at all.
Alzheimer’s Research UK encourages people to keep “mentally active” throughout life to boost their brain health.
“Regularly challenging our brain and staying mentally active can help protect our brain health as we age, lowering our risk of memory and thinking problems and dementia,” it says.
The BMJ study also revealed the impact of a dementia diagnosis on life expectancy by age and sex in one of the largest analyses to have been undertaken.
It found that men lived for an average of 5.7 years when they were diagnosed at age 65, and 2.2 years when diagnosed at 85. The figures ranged from 8.0 to 4.5 years respectively for women.
It also found that survival was longer among Asian populations than other ethnic groups, and among people with Alzheimer’s disease compared to other forms of dementia.
On average people spend about one third of their life after diagnosis in a nursing home, with more than half of people moving to a nursing home within five years.
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