June 14, 2010 -- There's no solid scientific proof that lifestyle measures can prevent Alzheimer's disease or cognitive decline, according to a federally convened panel of experts.
Staying healthy, exercising, eating a diet rich in omega-3 fatty acids and other healthful foods, and keeping your mind engaged have all been suggested as ways to stave off cognitive decline and the brain disorder known as Alzheimer's, marked by a loss of memory and other cognitive ability.
But the independent panel, convened by the National Institutes of Health, concludes that there is insufficient evidence that any of these measures prevent Alzheimer's.
The conclusion, although probably disappointing to many, may not be as discouraging as it sounds, says Carl C. Bell, MD, a panel member who is also director of the Institute for Juvenile Research, professor of psychiatry and public health, University of Illinois at Chicago, and president and CEO of the Community Mental Health Council, Chicago.
''We had to follow the science," he says, explaining that the panel applied rigorous scientific standards to the numerous studies reviewed to determine if any measures might be proven to prevent Alzheimer's disease or cognitive decline, which precedes it.
They found the evidence lacking, Bell tells WebMD. "There is no hard science right now."
But that doesn't mean there won't be, someday, says Martha Daviglus, MD, PhD, MPH, chair of the panel and professor of preventive medicine and medicine at Northwestern University's Feinberg School of Medicine. "Right now research is being conducted in promising areas, such as omega-3, physical activity, and cognitive engagement," she tells WebMD.
About 5.3 million Americans have Alzheimer's, the majority of them late-onset disease that becomes apparent after age 65.
The panel's report, as well as the background information supplied them, is published in the Annals of Internal Medicine.
The NIH-convened panel, made up of 15 independent experts, spent three days in April looking at data gathered by a team of experts from Duke University Medical Center and the Durham Veterans Administration Medical Center.
Brenda L. Plassman, PhD, a Duke researcher, and her colleagues gave the panel the results of a systematic review that included 127 observational studies each looking at 300 or more participants, 22 randomized, controlled studies with at least 50 participants followed for at least a year, and 16 systematic reviews of various preventive measures.
The study topics covered a broad range, from nutrition to medical factors and medication, social, economic and behavioral factors, exposures to toxin, and genetics.
Preventing Alzheimer's Disease: Panel Conclusions
Overall, the panel says: "Currently, firm conclusions cannot be drawn about the association of any modifiable risk factor with cognitive decline or Alzheimer's disease."
The panel also says the evidence is ''insufficient'' to support the use of pharmaceutical agents or dietary supplements to prevent cognitive decline or Alzheimer's disease.