Senior Citizens With Most Education Live Longer
Without Cognitive Loss but Die Faster
As education levels increase, time with cognitive
impairment declines
May 12, 2008 - Those with at least a high school
education spend more of their older years without cognitive loss –
including the effects of Alzheimer’s, Parkinson’s and dementia -- but
die sooner after the loss becomes apparent, reveals a new study
appearing in the June 2008 issue of the Journal of Aging and Health.
“These findings are consistent with the idea that
those with more education may process tasks more efficiently or use
other compensatory mechanisms that delay cognitive impairment or delay
our ability to detect impairment,” explained USC Davis School of
Gerontology professor Eileen Crimmins, corresponding author of the
study.
Using a nationally representative survey, Crimmins
and her co-authors tracked more than 7,000 people over the age of 70 for
seven years.
They found that a 70-year old person with at least
12 years of education can expect:
● To live 14.1 more years without cognitive
impairment, two-and-a-half years more than 70-year olds with fewer than
12 years of education.
● To spend 1 year of remaining life with
impairment, about 7 months less than a person with fewer years of
education.
“One implication of these findings is that as
education increases in the population, the length of time spent with
cognitive impairment should be reduced,” Crimmins said.
However, those with more education appeared to
exhibit more severe cognitive impairment — which may include memory
loss, loss of language or disorientation — and to be in worse health,
the researchers found.
“Surprisingly, the risk of dying among those with
cognitive impairment is generally higher for the more educated than for
the low education group, even though the possibility of becoming
cognitively impaired is lower for the higher education group,” Crimmins
said.
For example, 80-year olds with at least a high
school education have a 23 percent chance of dying within a year after
severe mental loss — about 6 percentage points more likely than
less-educated 80-year olds with impairment and four times more likely
than 80-year olds who are mentally sound.
Still, the researchers found that there is some
chance of recovery from severe cognitive loss in large populations.
Overall, about 11 percent of the mentally impaired will recover,
according to the study.
The researchers hypothesize that those with
treatable conditions such as depression and those recovering from
strokes or cancer treatments are more likely to regain mental abilities.
Specifically, they find that stroke is almost twice as prevalent among
the highly educated who recover than among those who remain impaired.
“The length of life with cognitive impairment will
increase as total life expectancy increases, unless the age at onset of
cognitive impairment is delayed, perhaps by addressing modifiable risk
factors,” Crimmins said. “Cognitive impairment is a major health problem
in old age and an area of growing concern for population health.”
Editor's Notes:
The research was supported by the National
Institute of Aging, the Institute for Longevity and Aging and the Robert
Wood Johnson Foundation’s Health & Society Scholars Program.
Agnčs Ličvre (Institut National d’Etudes
Démographiques, France), who was a postdoctoral student at USC, is the
lead author of the study. Dawn Alley (University of Pennsylvania), who
received her Ph.D. from USC, was also an author of the study.
Ličvre, Agnčs, Dawn Alley and Eileen Crimmins,
“Educational Differentials in Life Expectancy With Cognitive Impairment
Among the Elderly in the United States.” Journal of Aging and Health:
June 2008. DOI: 10.1177/0898264308315857
