Alzheimer's disease is the most common form of dementia and currently affects over 13 million people worldwide. The direct and indirect cost of Alzheimer care is over $100bn (€81bn) in the US alone. The direct cost of Alzheimer care in the UK was estimated at £15bn (€22bn).
Although the mechanism of Alzheimer's is not clear, significant data exists supporting the build-up of plaque from beta-amyloid deposits. The new research appears to indicate that curcumin, the natural pigment that gives the spice turmeric its yellow colour, could help the body's immune system clear away these deposits and reduce the risk of developing the disease.
"Curcumin improved ingestion of amyloid beta by immune cells in 50 percent of patients with Alzheimer's disease. These initial findings demonstrate that curcumin may help boost the immune system of specific Alzheimer's disease patients," said Dr Milan Fiala from the David Geffen School of Medicine at UCLA.
Curcumin has increasingly come under the scientific spotlight in recent years, with studies investigating its potential benefits for reducing cholesterol levels, improving cardiovascular health and cancer-fighting abilities.
The research, published in the Journal of Alzheimer's Disease (Vol. 10, pp. 1-7), adds to this by reporting on a small laboratory study using blood from six Alzheimer's disease patients (aged 65 to 84) and three healthy controls. The focus was on macrophages, the 'foot soldiers' of the immune system that clean up harmful waste products in the body, including beta-amyloid deposits.
The isolated macrophages were exposed to a curcumin-derived compound (provided by phytonutrient manufacturer Sabinsa Corporation) for 24 hours and then introduced beta-amyloid. It was found that macrophages from three out of six Alzheimer's disease patients showed improved uptake or ingestion of the waste product compared to the patients' macrophages not treated with curcumin.
The age of the patient and the stage of the Alzheimer's disease appeared to be key factors in the effectiveness of the curcumin compound, report the researchers, with younger patients and patients with early-stage Alzheimer's apparently more receptive to the benefits.
No effects were reported for the macrophages from the healthy controls when exposed the curcumin-derived compound.
"We are hopeful that these positive results in a test tube may translate to clinical use, but more studies need to be done before curcumin can be recommended," said Fiala.
The mechanism behind these apparent effects is not clear and significant further study is needed to further examine the potential effects. Some caution is also warranted due to curcumin levels in some patients already being relatively high due to participation in another UCLA study.
"Our next step will be to identify the factors that helped these immune cells respond," said co-researcher Laura Zhang from UCLA.
"Immunomodulation of the innate immune system by curcuminoids might be a safe approach to immune clearance of amyloidosis in Alzheimer's Disease brain," concluded the researchers.
The new study extends previous findings examining the neuroprotective effects of curcumin. Experts recommend however that consumers wishing to make use of curcumin's properties consume it in supplement form rather than eating more curries, which tend to be rather high in fat in their Western form.
The study was funded by the Alzheimer's Disease Association and private donors.