If laboratory findings hold true in people, treatment with one of the active chemicals in turmeric, the main spice found curry, may boost the immune system of patients with Alzheimer's disease and, thereby, increase the clearance of amyloid plaques in the brain, the primary abnormality seen in patients with the disease, researchers in the United States report.

In their study, Dr. Milan Fiala, from the Greater Los Angeles Veteran's Affairs Medical Center, and colleagues first show that immune cells called macrophages taken from patients with Alzheimer's disease cannot efficiently eliminate amyloid and that this may be related to the abnormal regulation of certain genes.

Treating these cells with an active substance found in turmeric, called bisdemethoxycurcumin, increases the production of some of the genes and enhances macrophage function, according to the team's report, published in the Early Edition of the Proceedings of the National Academy of Sciences.

The authors note that other Alzheimer's disease treatment strategies have attempted to increase the clearance of amyloid by stimulating the activity of certain cells located in the brain. By contrast, the current approach boosts amyloid clearance by enhancing the activity of macrophage cells derived from bone marrow.

Further studies are needed to determine if increasing blood levels of macrophages using an oral curcumin agent clear the amyloid plaques, and produce therapeutic effects, in patients with Alzheimer's disease, they add.