May Prevent Alzheimer's Disease
LONDON (AP) - You've heard it before: If you want
to remain healthy, eat more fruit and vegetables and less red
meat. But scientists now say such a diet also may help prevent
In fact, mounting evidence indicates the risk factors for heart
disease high blood pressure, diabetes, excess weight, high
cholesterol and lack of exercise may play a role in Alzheimer's.
New studies to be presented next week at an
international Alzheimer's conference in Stockholm establish the
big picture for the first time, giving scientists a better understanding
of how to reduce the likelihood of the disease.
Over the last few years, hints of a connection
between Alzheimer's and lifestyle have emerged, but scientists
have become increasingly interested in investigating such a link
and are just now beginning to realize that what is good for the
heart may also be good for the brain.
Alzheimer's is a degenerative brain disease
that causes memory loss, disorientation, depression and decay
of bodily functions. The disease afflicts about 12 million people
worldwide, including more than 4 million Americans. It is increasing
so fast that more than 22 million people worldwide will be affected
by 2025, experts predict.
Scientists do not know what causes the sticky
brain deposits that inevitably kill off neural cells until memory
disintegrates and ultimately the patient dies. The biggest risk
for Alzheimer's is simply age: Alzheimer's cases double with every
five years of age between 65 and 85.
"While more research is necessary, especially
in the form of prevention trials, we're seeing the strongest evidence
yet that there is a relationship between healthy aging and a reduced
risk of Alzheimer's," said William Thies, vice president of medical
and scientific affairs at the Chicago-based Alzheimer's Association.
Several studies to be presented at the International
Conference on Alzheimer's Disease and Related Disorders indicate
that people may be able to reduce their chances of developing
Alzheimer's by treating high blood pressure.
One 21-year study, by Miia Kivipelto of the
University of Kuopio in Finland, examined 1,449 people. It found
that the high cholesterol and high blood pressure seemed to be
more strongly linked to the risk of developing Alzheimer's than
was a certain gene variation.
However, it seems that having high blood pressure
only in later life is not connected to Alzheimer's.
"Since high blood pressure can be controlled,
we may have identified something people can do to lower their
chance of developing Alzheimer's," said Thies, who was not connected
with the research.
Researchers at Case Western University School
of Medicine and University Hospitals of Cleveland, Ohio, found
that a diet of more fruit and vegetables, and less red meat, offers
more protection against the development of Alzheimer's.
Collecting data regarding what foods people
ate during adulthood, Grace Petot and her colleagues discovered
that low-fat diets containing vitamins such as A, C and E in fruit
and vegetables are associated with a reduction in risk for Alzheimer's.
Three other studies to be presented at the conference
in Stockholm, the largest gathering ever of Alzheimer's researchers,
bolster evidence that taking cholesterol-lowering drugs could
reduce the chances of developing Alzheimer's.
A study by Dr. Robert Green at Boston University
School of Medicine found that people taking cholesterol drugs
called statins reduced their risk of developing Alzheimer's by
79 percent. With 2,378 patients, it is the largest study to investigate
the connection and the first to include large numbers of black
people, who are disproportionately likely to develop Alzheimer's.
The study also found that types of cholesterol-lowering
drugs other than statins were not linked with a reduced risk of
High cholesterol can narrow the arteries and
raise the risk of heart disease. Some researchers think high cholesterol
may also affect brain arteries and promote the clumping of the
protein beta-amyloid, which is thought to damage the brain in
Beta-amyloid occurs normally in the body, but
can accumulate in the spaces between brain cells and create plaques
in the brain. These plaques are linked to the death of brain cells,
causing a gradual loss of memory and control of body function,
and leading eventually to death. By the time a patient has noticeable
symptoms of Alzheimer's, substantial amounts of amyloid have built
up in the brain, experts say.
A study to be presented at the conference by
researchers at St. George's Medical School in London found statins
dramatically reduced the production of beta-amyloid.
"The small amounts of beta-amyloid normally
found in the blood of healthy people are quickly cleared from
the brain," said the study's leader Brian Austen. "In the general
population, people taking statins to reduce their blood cholesterol,
for whatever reason, have a 70 percent reduction rate for Alzheimer's."
Advances in the understanding of how beta-amyloid
acts have prompted researchers to focus much of their effort on
trying to block plaque formation.
Other research highlights of the conference
involve new ways of seeing what's going on inside the brains of
Alzheimer's patients. Until recently, Alzheimer's could only be
confirmed by examination of the brain after death.
One study outlines how a new dye could show
where plaques are located in the brain. The study, conducted by
scientists at Uppsala University in Sweden, found the dye went
to areas of the brain where plaques are usually seen in autopsies
and that very little of the dye lingered in the brains of people
who had no mental impairment.
"Having the ability to quantify amyloid deposition
in the brain will have a profound impact on our ability to monitor
the progression of Alzheimer's as well as gauge the effectiveness
of medical treatments," said Thies of the Alzheimer's Association.
The conference, to be held July 20 through July
25, will involve about 4,000 Alzheimer's researchers.
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