Despite years of speculation about the best way to prevent Alzheimer's disease, there's no proof yet that anything can stave off the devastating and incurable brain breakdown, an expert panel has concluded.
"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," said Dr. Martha Daviglus of Northwestern University in Chicago, who chaired an independent panel meeting at the National Institutes of Health outside Washington.
The group of experts looked at the dozens of studies that have suggested ways to prevent Alzheimer's — everything from doing puzzles to increasing social interaction — and found none were strong enough to constitute proof.
Most of the studies that have been done show associations, but not cause and effect, Daviglus said.
"These associations are examples of the classic chicken or the egg quandary. 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?" she asked.
The 15 experts met under the NIH's state-of-the-science conference program, which aims to direct future research in an important study area.
They included specialists in geriatrics, long-term care, nursing, psychiatry and other fields. Panelists may not be federal government employees, nor may they have financial stakes in any treatments considered.
The report is available here.
Disease not fully understood
The Alzheimer's Association says as many as 5.3 million Americans have Alzheimer's and projects that 16 million may have it by 2050.
"It is critical that we, as a nation, significantly increase investments in Alzheimer research," the group said in a statement.
"The total payments for health and long-term care services for people with Alzheimer's and other dementias will amount to $172 billion from all sources in 2010."
The panel found there were inconsistent definitions of what constitutes Alzheimer's disease and the cognitive decline that leads up to it.
Doctors also do not fully understand how the disease develops — for instance, there is disagreement on whether the amyloid plaques found in the brains of victims cause the disease or are merely a symptom.
There are a few drugs to treat Alzheimer's but their effects are temporary. Genetics are strongly involved, and blacks and other minorities have a higher risk than whites.