Curcumin, a component of curry and turmeric,
seems to help the immune system get rid of
amyloid beta -- the protein that builds up
to form damaging plaques in the brains of
Alzheimer's patients.
The findings build on previous research linking
curry consumption to reduced Alzheimer's risk,
including one study that found that only 1
percent of elderly Indians developed the disease
-- a quarter of the rate seen in the United
States.
Now, preliminary findings from the University
of California, Los Angeles, suggest that curcumin
comes to the aid of immune system cells called
macrophages to clear away amyloid beta.
"We know that macrophages aren't working
properly in Alzheimer's patients, since they
seem to be defective in cleaning amyloid-beta
from brain slices", explained lead researcher
Dr. Milan Fiala, a researcher with the David
Geffen School of Medicine at UCLA and the
VA Greater Los Angeles Health Care System.
"We have found that curcumin can help
some macrophages to function properly in a
test tube," Fiala said. He said more
work is needed to see if the spice works similarly
in the human brain, however.
Curcumin is already known for its anti-inflammatory
and antioxidant properties. Earlier research
by another UCLA team found that curcumin-fed
mice with Alzheimer's plaques experienced
a decrease in inflammation and reduced plaque
formation.
The new findings are in current issue of
the Journal of Alzheimer's Disease.
In the study, the UCLA researchers obtained
blood samples from six Alzheimer's patients
and three healthy controls. They next isolated
macrophages and treated them with a curcumin
solution for 24 hours, then added amyloid
beta.
Macrophages from three of the Alzheimer's
patients were observed to start ingesting
the plaque-forming proteins.
Over the past five years, Fiala's team has
studied the immune function of over 100 Alzheimer's
patients. Last June, the team helped establish
the immune system's key role in Alzheimer's
disease.
"Our research has helped to identify
why the brain isn't being cleared of amyloid
beta in Alzheimer's disease patients,"
Fiala said. "The immune system can attack
and remove amyloid-beta from the brain, but
the job is not done properly in Alzheimer's
patients."
Fiala said macrophages may be as important
for Alzheimer's disease as insulin is for
diabetes. "If we can improve the immune
system, we can help the body's natural ability
to clear damaging plaques," he said.
"In terms of treatment implications,
it's very interesting that curcumin seems
to help the brain clear away beta amyloid,"
noted Dr. Sam Gandy, chair of the medical
and scientific advisory council at the Alzheimer's
Association.
"The study also shows an additional
mechanism [besides curcumin's anti-inflammatory
and anti-oxidant properties] that looks at
the actual clean-up of plaques," said
Gandy, who is also director of the Farber
Institute for Neurosciences at Thomas Jefferson
University in Philadelphia.
Fiala believes his team's research into the
role of macrophages in Alzheimer's disease
patients may one day point to new approaches
for diagnosing -- and even treating -- the
illness.
Testing immune-cell response may also offer
other researchers a novel way to assess the
effectiveness of drugs in clearing amyloid
beta from the brain. It might also help doctors
individualize treatment, Fiala said.
Curcumin appears to have few side effects,
if any, he added. "We can only say what
we see in test tubes, but we don't see any
toxic effects with curcumin, even administered
in high doses," Fiala said.
Curcumin's health benefits may extend beyond
Alzheimer's disease. One recent six-month
study, carried out by researchers at Johns
Hopkins University, Baltimore, found that
daily doses of the spice were associated with
a nearly 60 percent lower risk for colon polyps,
a known precursor to colon cancer.
So, experts say, while it may be too early
to recommend a dish of curry to help stave
off cancer or Alzheimer's, it nonetheless
appears healthy -- and tasty -- to add curry
powder to your spice rack.
