THURSDAY, Jan. 5 (HealthDay News) -- Sorry, Boomers, but a new
study suggests that memory, reasoning and comprehension can start
to slip as early as age 45.
This finding runs counter to conventional wisdom that mental
decline doesn't begin before 60, the researchers added.
"Cognitive function in normal, healthy adults begins to decline earlier than previously thought," said study author Archana Singh-Manoux.
"It is widely believed that cognitive ability does not decline before the age of 60. We were able to show robust cognitive decline even in individuals aged 45 to 49 years," added Singh-Manoux, research director at INSERM's Center for Research in Epidemiology & Population Health at the Paul-Brousse Hospital in Paris.
These findings should be put in context of the link between
cognitive function and the dementia, Singh-Manoux said.
"Previous research shows small differences in cognitive performance in earlier life to predict larger differences in risk of dementia in later life," she said.
Understanding cognitive aging might enable early identification
of those at risk for dementia, Singh-Manoux said.
The report was published in the Jan. 5 issue of
For the study, Singh-Manoux and colleagues collected data on
nearly 5,200 men and 2,200 women who took part in the Whitehall II
cohort study. The study, which began in 1985, followed British
civil servants from the age of 45 to 70.
Over 10 years, starting in 1997, the participants' cognitive
function was tested three times. The researchers assessed memory,
vocabulary, hearing and vision.
Singh-Manoux's group found that over time, test scores for
memory, reasoning and vocabulary skills all dropped. The decline
was faster among the older participants, they added.
Among men aged 45 to 49, reasoning skills declined by nearly 4
percent, and for those aged 65 to 70 those skills dropped by about
nearly 10 percent.
For women, the decline in reasoning approached 5 percent for
those aged 45 to 49 and about 7 percent for those 65 to 70, the
"Greater awareness of the fact that our cognitive status is not intact until deep old age might lead individuals to make changes in their lifestyle and improve [their] cardiovascular health, to reduce risk of adverse cognitive outcomes in old age," Singh-Manoux said.
Research shows that "what is good for the heart is good for the
head," which makes living a healthy lifestyle a part of slowing
cognitive decline, she said.
Targeting patients who have risk factors for heart disease such
as obesity, high blood pressure and high cholesterol might not only
protect their hearts but also prevent dementia in old age, the
"Understanding cognitive aging will be one of the challenges of this century," especially as people are living longer, they added.
In addition, knowing when cognitive decline is likely to start
can help in treatment, because the earlier treatment starts the
more likely it is to be effective, the researchers noted.
Francine Grodstein, an associate professor of medicine at
Brigham and Women's Hospital in Boston and author of an
accompanying editorial, said more research is needed into how to
prevent early cognitive decline.
"If cognitive decline may start at younger ages, then efforts to prevent cognitive decline may need to start at younger ages," she said.
"New research should focus on understanding what factors may contribute to cognitive decline in younger persons," Grodstein added.
"This is consistent with what we have seen in other studies and the cognitive changes that occur as we age," said Heather M. Snyder, senior associate director of medical & scientific relations at the Alzheimer's Association.
These changes do not mean that all these people will go on to
develop Alzheimer's disease or another dementia, Snyder noted. "It
is important to remember that the cognitive changes associated with
aging are very different from the cognitive changes that are
associated with Alzheimer's disease," she stressed.
Although some of these people may go on to develop Alzheimer's
disease there is currently no way to tell who is at risk, Snyder
said. "This is why it is so important to continue to investigate
biological changes that occur in the earliest stages, because it is
difficult to [determine] the cognitive changes that are associated
with Alzheimer's disease," she said.
Snyder noted that Alzheimer's disease can start 15 to 20 years
before symptoms are apparent, which makes finding a biological
marker so important. "If a therapeutic is available, we can
intervene at that point," she said.
To learn about cognitive decline, visit the
U.S. National Library of Medicine.