Self-Discipline May Reduce Alzheimer's Risk
People who are meticulous and "finish what
they start" may have a reduced risk of developing Alzheimer's disease, according
to a study involving Catholic nuns and priests.
The most conscientious and
self-disciplined individuals were found to be 89% less likely to develop this
form of dementia than their peers over the course of the 12-year
study.
Robert
Wilson at Rush University Medical Center in Chicago, Illinois, US, and
colleagues followed 997 healthy Catholic nuns, priests and Christian brothers
between 1994 and 2006. Early on in the study, participants completed a
personality test to determine how conscientious they
were.
Based on answers to 12 questions such as
"I am a productive person who always gets the job done", they received a score
ranging from 0 to 48. On average, volunteers scored 34 points in the
test.
Controlled impulses
Volunteers also underwent regular
neurological examinations and cognitive tests. Over the lifetime of the study,
176 of the 997 participants developed Alzheimer's disease. However, those with
the highest score on the personality test – 40 points or above – had an 89%
lower chance of developing the debilitating condition than participants who
received 28 points or lower.
"These are people who control impulses,
and tend to follow norms and rules," Wilson told New Scientist.
Previous studies suggest that exercise and
intellectual stimulation can decrease the risk of
Alzheimer's disease. But the link between self-discipline and a reduced risk of
the illness remained strong even after researchers discounted these factors from
their study. Subjects still had a 54% lower chance of developing the
condition.
Exactly why conscientiousness should have
an impact on Alzheimer's risk remains unclear, says Wilson. He notes that brain
autopsies conducted on 324 of the study's participants failed to resolve the
mystery.
Alzheimer's test?
Earlier work has linked the presence of
plaques and protein tangles within the brain to Alzheimer. Yet, in general, the
brains of those who scored highly on the conscientiousness test had as many
plaques and protein tangles as those of subjects who scored
lower.
Wilson suggests that more meticulous and
conscientious individuals may have more active frontal brain regions, an area
that is responsible for decision-making and planning. Increased activity in this
region may perhaps compensate for a decline in function in other brain regions,
he speculates.
Based on the new findings, doctors could
perhaps consider certain patients at greater risk of
dementia, says Ross Andel at the University of South Florida, US. "This
is a study about identifying people at risk," he
says.
Journal reference: Archives of General Psychiatry (vol 64, p 1204)