2006-10-27
HealthDay News

FRIDAY, Oct. 27 (HealthDay News) -- 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.

More information

Find out more about Alzheimer's treatments at the Alzheimer's Association.