NEW YORK, Aug 08 (Reuters Health) - Anti-inflammatory drugs like ibuprofen
may be able to delay or even prevent some of the brain damage associated with
Alzheimer's disease, new research suggests.
Other studies have indicated that people who use nonsteroidal
anti-inflammatory drugs (NSAIDs) have a lower risk of Alzheimer's; now
scientists have the first direct evidence that an NSAID prevents
Alzheimer's-like damage in animals.
In experiments with mice engineered to develop Alzheimer's-like damage,
researchers found that those fed ibuprofen for 6 months developed half as many
brain "plaques"--the protein deposits in the brain that are the hallmark of
Alzheimer's disease.
This marks the first time an animal study has confirmed what some human
studies have suggested--that, if started early enough, regular NSAID use might
stave off Alzheimer's.
"There is already pretty strong suggestive evidence that this will work in
humans, too," study lead author Dr. Gregory M. Cole told Reuters Health in an
interview.
That evidence comes from epidemiological studies in which people who
reported past NSAID use were less likely to develop Alzheimer's. And the longer
people took NSAIDs, the lower their risk.
One study, Cole pointed out, suggested the drugs could cut Alzheimer's risk
in half.
Cole, the associate director of the Alzheimer's Center at the University of
California, Los Angeles, and his colleagues report their findings in the August
1st issue of The Journal of Neuroscience.
Alzheimer's disease currently afflicts about 4 million Americans, and
experts predict there will be a dramatic rise in cases over the next few
decades.
The disease is characterized by brain deposits called plaques and tangles;
these deposits begin to form about 20 years before symptoms of dementia arise,
according to Cole. If NSAIDs can cut the deposits in half, he said, that could
delay the onset of Alzheimer's by 10 years--effectively preventing it in many
people.
That NSAIDs actually prevented deposits was unexpected, Cole added. One
might expect NSAIDs to reduce inflammation in the brain--another sign of
Alzheimer's since inflammation is a response to damage. However, Cole and his
colleagues were surprised to find that ibuprofen reduced brain deposits as well.
Cole compared the brain deposits to splinters in the skin. "You'd expect
that an NSAID would get rid of the inflammation around the splinter, but not the
splinter itself. Here, we got rid of half of the splinters."
Trials will soon get under way to see whether long-term use of ibuprofen and
other NSAIDs prevent Alzheimer's in humans, according to Cole. It may be 7 years
until there are any results, however.
Cole believes that anyone who does not suffer side effects from regular
ibuprofen use may do well to take it up. "I think a lot of people could reduce
their Alzheimer's risk by taking ibuprofen right now," he said. "It's perfectly
reasonable to tell people to do that."
But other researchers disagree. "People need to seek the advice of their
physicians before they take any drug, especially ones like these," Maria Norton,
a doctoral candidate in the department of psychology at the Utah State
University in Logan, told Reuters Health in June. "Just because something may
reduce your Alzheimer's risk doesn't mean you should run out and take it. The
side effects of these drugs and their potential reactions with other drugs are
significant. NSAIDs can cause gastrointestinal bleeding and liver toxicity."
Professor John Breitner of Johns Hopkins School of Public Health in
Baltimore, Maryland, agreed. "There are good reasons unrelated to Alzheimer's
disease for people to start taking low-dose aspirin," he said, "but I wouldn't
want people to start taking high doses of NSAIDs."
Norton and Breitner were part of a team that published a paper in the June
issue of the journal Neurology. The 5-year study of more than 5,000 residents
aged 65 or older in Cache County, Utah, found that NSAIDs had a strong
protective effect against the development of Alzheimer's.
A trial sponsored by the National Institute on Aging may provide a
definitive answer. The study, which is just getting started, will include 2,600
people over the age of 70 who have a history of dementia in their family, but no
signs of Alzheimer's themselves. As the participants are followed over several
years, the investigators will monitor whether those taking NSAIDs such as
naproxen or Celebrex are less likely to develop the condition.
