Use it or lose it: Doing brain-stimulating activities from childhood – like
reading books, writing letters and solving everyday problems – to old age
may help prevent clinical signs of dementia
such as memory loss, a new study finds.
"Certain things increase or decrease your vulnerability to cognitive
[mental] decline," said Robert Wilson, the study's lead author. Keeping
your brain active seems to help certain brain circuits to operate effectively,
even if a gradual build-up of brain disease is already occurring, said Wilson,
a professor of neurological and behavioural sciences at Rush University Medical
Centre, in Chicago.
People who engaged in frequent mental activity in later life had a rate of
mental decline that was 32% lower than those with average activity. Meanwhile,
those with infrequent mental activity experienced a decline in mental abilities
that was 48% faster.
The research, published online July 3 in the journal Neurology, helps
explain why one-third of people die in old age with little or no signs of
problems with thinking, learning or memory, yet when brain autopsies are done,
they actually have clear evidence of Alzheimer's disease,
Wilson said. "They [technically] have the disease, but it's not expressed
clinically," he said.
That idea that the brain somehow creates a "work-around" to avoid
showing signs of Alzheimer's or other dementia is often referred to as the
"cognitive reserve hypothesis", Wilson said. That concept suggests
that people with greater thinking, learning and memory abilities are somehow
able to delay symptoms of Alzheimer's. But proving the hypothesis has been
challenging for scientists.
"There's been this long-term debate in the field about how cognitive
activities preserve cognition," said Prashanthi Vemuri, an assistant
professor of radiology at the Mayo Clinic in Rochester, Minnesota, who wrote an
editorial accompanying the study. The question has essentially been: Which
comes first, the chicken or the egg?
"Does engagement in cognitive activities slow cognitive decline, or are
people less interested in doing cognitive activities because they have problems
with dementia?" Vemuri said. She thinks the study breaks new ground.
"It confirms that whatever is happening in the brain is happening, but the
cognitively stimulating activities a person does independently slow down the
progression of the disease."
How do intellectually challenging activities help support brain function?
The brain tries to constantly adapt to the challenges it's asked to do,
Wilson explained. "The brain is experience dependent," he said.
"Activities that are sustained are going to impact its structure and
function. And cognitive circuits that are elaborately structured and
functioning very well are able to adapt when the inevitable onslaught of aging
The researchers conducted long-term follow-up and actually performed autopsies
of the participants' brains after death to confirm the absence or presence of
disease, Vemuri said.
The scientists began back in 1997, asking 294 participants – all older than
55 – to report on their lifetime and recent thinking-related activities, from
childhood to young adulthood, middle age and the present. They tested
participants' memory and thinking ability regularly, and did annual
neurological exams. The participants were about 68% women, had 14 years of
education and 37% had mild thinking impairment when they started in the study.
After each participant died, examiners who had no knowledge of the clinical
evaluation data did an independent inspection of the brain, looking for
established signs of dementia, called plaques, tangles, infarcts and Lewy
The researchers then compared those brain findings to the data they had
collected, and found that current mental activity slowed the rate of mental
decline years before death.
A cognitively stimulating lifestyle
Wilson pointed out that the research doesn't prove cause and effect. A
clinical trial would be needed for that – which involves randomly assigning
people to one set of behaviours or another – and that would be unethical and
inordinately expensive, he said. But he's now doing neuro-imaging studies to
better understand what it is about a cognitively stimulating lifestyle that
helps protect the brain.
As for how to best protect your brain, Wilson recommended finding real-world
activities – rather than just crossword puzzles or Sudoku games – that include
a combination of challenges and the need to focus and concentrate. "Find a
hobby that is sustainable: quilting, photography, acting in the theatre, even
learning Morse code," he suggested. "Physical
activity is also important."
Vemuri encouraged people to start developing their thinking and memory
skills as early as possible. "Parents should know that reading programmes at
a young age will help their kids have a good old age," she said.
Learn more about dementia and Alzheimer's disease from the U.S. Centers for Disease Control and Prevention.