No evidence Alzheimer's prevention works

BETHESDA, Md., April 28 (UPI) -- U.S. medical investigators said Wednesday there is no firm evidence any preventive measures for cognitive decline or Alzheimer's disease are effective.

An independent panel convened by the National Institutes of Health said many preventive measures including mental stimulation, exercise and a variety of dietary supplements have been studied over the years. But the experts said the value of such strategies for delaying the onset or reducing the severity of decline or disease has never been demonstrated by rigorous studies.

"Alzheimer's disease is a feared and heart-breaking disease," said Dr. Martha Daviglus, the panel's chairwoman and a professor of preventive medicine at Northwestern University. "We wish we could tell people that taking a pill or doing a puzzle every day would prevent this terrible disease, but current evidence doesn't support this."

The panel's members said they found no evidence of even moderate scientific support associating any dietary supplement, prescription or non-prescription drug, diet, exercise or social engagement with reduced risk of Alzheimer's disease. The panel said evidence surrounding risk reduction for cognitive decline is similarly limited, although low-grade evidence shows weak associations between many lifestyle choices and reduced risk of Alzheimer's disease and cognitive decline.

"These associations are examples of the classic chicken or the egg quandary," Daviglus said. "Are people able to stay mentally sharp over time because they are physically active and socially engaged or are they simply more likely to stay physically active and socially engaged because they are mentally sharp?" Daviglus said.

The panel included experts in preventive medicine, geriatrics, internal medicine, neurology, neurological surgery, psychiatry, mental health, nutrition, pharmacology, genetic medicine, nursing, health economics, health services research and family care-giving.

The report is available at http://www.ahrq.gov/downloads/pub/evidence/pdf/alzheimers/alzcog.pdf.