If you have high blood pressure and haven't treated it yet, consider
this: getting it under control may also reduce your risk of dementia,
suggests a study out Monday.
Men who had been treated with
anti-hypertensive drugs were found in autopsies to have fewer
microinfarcts (a sign of small strokes), fewer amyloid plaques and
tangles (signs of Alzheimer's disease) and less brain atrophy.
on beta blockers, one of the least recommended medicines because of
their side effects, had the healthiest brains, compared with other
treatments. They had "about half as severe damage,'' says lead author
and physician Lon White, but anyone who was treated "fared better than
those who had no treatment.''
"What we're seeing is another
advantage of treating hypertension,'' says White, of the Pacific Health
Research and Education Institute in Honolulu. "It reduces heart disease
and stroke, but we're saying it looks like it can also reduce all kinds
About 1 in 3 U.S. adults, an estimated 68 million,
have high blood pressure and about half of them don't have it under
control, according to the Centers for Disease Control and Prevention.
Called the silent killer, hypertension has no symptoms or warning signs,
and many people don't know they have it.
Blood pressure is
measured by two numbers: systolic (blood pressure in veins when the
heart is pumping) and diastolic (blood going through the heart when it
is at rest). Normal blood pressure is when systolic is below 120 and
diastolic is below 80.
The findings are being presented in March at the American Academy of Neurology's annual meeting. The report is posted on the AAN website.
study involved 774 Japanese American men who took part in the Honolulu
Asia Aging Study, one of the "largest group of brain autopsies'' ever
done in research, White said. The only way to confirm most dementias is
by autopsy findings.
The brain relies on healthy arteries to
deliver a steady supply of blood. Hypertension damages the arteries, by
turning an open and flexible channel into a thick and stiff one, known
as arteriosclerosis. Two kinds of dementia, vascular dementia and mild
cognitive impairment, occur from a narrowing and blockage of the
arteries brought on by high blood pressure. Also, brain damaging strokes
can occur after blood clots form in arteries and interrupt blood flow.
blockers are not the first line of treatment for high blood pressure,
according to guidelines issued by the Joint National Committee on the
Prevention, Detection and Treatment of High Blood Pressure. Researchers
not associated with the study say that in most instances, they're often
the last recommended treatment and in some countries they're little used
because of their side effects and complications they cause in managing
other diseases, such as diabetes. Beta blockers can increase the risk
of stroke in the elderly and they can cause confusion and erectile
dysfunction, according to Sripal Bangalore, a cardiologist and assistant
professor of medicine at the NYU Langone Medical Center in New York,
who was not associated with the new study.
"This study raises more
questions than it answers, but nevertheless it calls for randomized
trials to test these associations between beta blockers and their
protection against dementia,'' Bangalore says. "The timing of this study
is interesting because new guidelines to treat hypertension are
expected to come out this spring."
"Maybe we need to think more
about using beta blockers to help control dementia," says JoAnne Foody,
co-director of cardiovascular wellness and prevention cardiology at
Brigham and Women's Hospital in Boston.
Beta blockers slow the
heartbeat, reduce the force of the heart muscle's contractions, and
decrease blood vessel contraction in the heart, brain and the rest of
the body. Other drugs -- such as diuretics, ACE inhibitors and calcium
channel blockers -- treat hypertension in other ways.
Most patients require a "cocktail of multiple drugs" to treat hypertension, says Foody.
says he hypothesized that he'd see the results between beta blockers
and microinfarcts, but was surprised he found a lower number of amyloid
plaques and tangles in Alzheimer's patients.
"My thought was
maybe if you lower heart rate, you'd have less arteriosclerosis over
the decades,'' says White. " My guess was that the accumulated injury
over the years was less. But we don't really know why. Maybe the heart
needs a little less pounding later in life."