MONDAY, March 7 (HealthDay News) -- Genetics may predispose some
people who live in so-called "hazardous" neighborhoods -- where
fear and stress are a fact of daily life -- to face a higher risk
for age-related cognitive decline, new research warns.
The culprit is a specific abnormality of the apolipoprotein E
gene. The study authors noted that while this gene is known to play
a key role in the normal maintenance of basic neurological health,
a certain mutation of this gene has also previously been linked to
a higher risk for the early onset of Alzheimer's disease.
Now a team of researchers led by Brian K. Lee, of Drexel
University in Philadelphia, has found that those carrying the
mutation may also face a higher risk for cognitive impairment when
they get older, if they live in the kind of threatening environment
that routinely elicits "a biological stress response."
The observation is reported in the March issue of the
Archives of General Psychiatry.
The new finding stems from an analysis of mental health data
collected during the Baltimore Memory Study, which involved more
than 1,100 urban residents living in 63 Baltimore
neighborhoods.
All of the study participants were between the ages of 50 and
70. About 54 percent were white; nearly 42 percent were black.
As a whole, 30 percent were found to carry at least one mutation
of the gene in question, the researchers found. However, blacks
were more likely to carry the mutation than whites (37.3 percent
versus 24.7 percent, respectively).
Genetics, in fact, wasn't the sole determinant of how well a
person performed on cognitive tests. Any participant living in a
stress-inducing environment, regardless of whether they possessed
the mutation in question, performed "substantially" worse on the
series of tests, which among other things included a focus on
language skills, verbal memory and learning, eye-hand coordination
and visual memory.
What's more, among those
without the telltale mutation, those living in relatively
more hazardous neighborhoods performed no worse on cognitive
testing than those living in better neighborhoods. And among those
with the mutation, those living in relatively better conditions
executed the test skills equally well as those without the
mutation, according to the study authors.
However, Lee's team found that those who carried the mutation,
and also lived in neighborhoods characterized as the most
psychosocially hazardous, performed the worst in terms of cognitive
skills such as eye-hand coordination, task execution, processing
speed and visual-spatial abilities.
More information
For more on mental health, visit the
U.S.
National Institute of Mental Health.