- In the latest work to show that vitamins may protect
against dementia, new studies suggest that eating nuts, leafy green vegetables
and other foods rich in antioxidants such as vitamin E may reduce the risk
of Alzheimer's.
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- The latest studies seem to suggest that vitamin-rich
foods, but not vitamin supplements, have beneficial effects. The researchers,
however, said more definitive studies are needed.
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- The connection, at least, is considered plausible: Antioxidant
vitamins have been shown to block the effects of oxygen molecules called
free radicals, which can damage cells and are thought to contribute to
cancer and heart disease. And lesions typically associated with exposure
to free radicals have been found in the brains of Alzheimer's patients.
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- One of the studies found strong effects from vitamins
E and C. In the other, results from vitamin E foods were more conclusive,
but researchers said there was a suggestion vitamin C also provided benefits.
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- Previous research suggested that vitamin E pills could
slow disease progression in people already diagnosed with Alzheimer's.
The new studies examined people who had not developed the mind-robbing
ailment at the outset and suggested no effect from pills. But pill use
was somewhat uncommon and of comparatively short duration in both studies.
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- The studies appear in Wednesday's Journal of the American
Medical Association.
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- One study, funded by the National Institute on Aging,
involved 815 Chicago residents 65 and older who had no initial symptoms
of mental decline. They were questioned about their eating habits and followed
for an average of about four years.
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- Alzheimer's developed in 131 participants. It was diagnosed
in 14.3 percent of those with the lowest intake of vitamin E foods, compared
with 5.9 percent of those with the highest intake. When factors such as
age and education were taken into account, the highest-intake group faced
a 70 percent lower risk of developing the disease.
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- Alzheimer's is a degenerative brain disease that usually
begins gradually, causing a person to forget recent events or familiar
tasks. How rapidly it advances varies from person to person, but the disease
eventually leads to confusion, personality and behavior changes and impaired
judgment. Communication becomes more difficult as the disease progresses,
leaving those affected struggling to find words, finish thoughts or follow
directions. Eventually, most people with Alzheimer's disease become unable
to care for themselves. One in 10 people over 65 and nearly half of those
over 85 suffer from Alzheimer's disease.
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- Today, 4 million Americans have the condition. That number
could jump to 14 million by the year 2050 unless prevention methods are
developed.Scientists still are not certain of the disease's cause.
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- Advancing age and family history are risk factors. Researchers
are exploring the role of genetics in the disease, but most agree it's
caused by a variety of factors.There is no single, comprehensive diagnostic
test for Alzheimer's disease. Instead, doctors rule out other conditions
through a process of elimination. They usually conduct physical, psychological
and neurological exams and take a thorough medical history.
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- Diagnosis is about 90 percent accurate, but the only
way to confirm it is through autopsy. There is no medical treatment currently
available to cure or stop the progression of Alzheimer's disease. There
are currently four FDA-approved Alzheimer's drugs -- Cognex, Aricept, Exelon
and Reminyl -- that may temporarily relieve some symptoms of the disease.
Several other drugs are in development.Common symptoms of Alzheimer's disease
include:
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- * Memory loss that affects job skills * Difficulty performing
familiar tasks * Problems with language * Disorientation to time and place
* Poor or decreased judgment * Problems with abstract thinking * Placing
items in inappropriate places * Rapid changes in mood or behavior * Dramatic
changes in personality * Loss of initiative
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- Source: Alzheimer's Association
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- Intake of vitamin C, found in foods such as citrus fruits,
also appeared to have offer some protection, but those results were not
statistically significant, said lead researcher Martha Clare Morris of
Rush-Presbyterian-St. Luke's Medical Center in Chicago.
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- Morris said participants with the highest vitamin E intake
ate amounts that could be obtained from a diet that includes whole-grain
cereal for breakfast, a sandwich with whole-grain bread for lunch and a
dinner including a green leafy salad sprinkled with nuts. There was no
protective effect in participants with a gene variation called apoplipoprotein
E-4, which has been linked to the development of Alzheimer's.
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- SECOND STUDY
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- The other study, from Erasmus Medical Center in Rotterdam,
involved 5,395 people in the Netherlands 55 and older who were followed
for an average of about six years.
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- Alzheimer's developed in 146 participants. Those with
high intakes of vitamins E and C were less likely to become afflicted,
regardless of whether they had the gene variation.
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- "The idea that vitamin E and vitamin C might have
beneficial effects on the underlying Alzheimer's disease process makes
sense, and it seems unlikely that antioxidant-rich foods would negatively
affect brain aging," Daniel Foley of the National Institute on Aging
and Dr. Lon White of Pacific Health Research Institute in Honolulu said
in an accompanying editorial.
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- Still, they noted several limitations in both studies,
including relying on participants' memories of their eating habits and
not following them longer.
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- National Institute on Aging scientist Neil Buckholtz
said several NIA-funded studies are attempting to help answer whether antioxidants
in food or pills affect mental decline.
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- VITAMIN B MAY ALSO HELP
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- Other work has hinted that high levels of the amino acid
known as homocysteine may also be associated with Alzheimer's disease,
suggesting that folic acid and other B vitamins may offer some protection.
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- There's no question, experts say, that folic acid and
B vitamins break down homocysteine in the body, thereby reducing blood
levels. But the link between homocysteine and dementia still needs to be
confirmed.
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- Researcher A. David Smith of the University of Oxford
in Oxford, England, cautioned that people should not take folic acid supplements
without consulting a physician. But he said that there are steps one can
take to ensure healthy homocysteine levels:
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- Quit smoking. Lighting up is known to raise homocysteine
levels.
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- Limit caffeine intake. Drinking five or more cups of
coffee a day raises homocysteine levels. Eat plenty of fruits and vegetables.
A well-balanced diet with at least five portions of fresh fruits and vegetables
per day is the best way to keep homocysteine levels normal, experts say.
Dark green leafy vegetables, orange juice and organ meats are also good
sources of folic acid.
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- Eat fortified grains. Since fortification of enriched
cereal grains began, folic acid can be found in enriched bread, pasta,
flour, crackers, breakfast cereal, rice and many other foods in the United
States.
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- Finally, Smith advised: Walk instead of driving, and
take the stairs instead of the elevator. Sedentary lifestyles have been
linked to Alzheimer's disease.
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- The Associated Press contributed to this report. http://www.msnbc.com/news/772258.asp?0na=x224A2B0-
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