Study: Diet, drugs, ‘brain games’ don’t prevent dementia

A major new study offers discouraging news about dementia: Nothing is yet proven to prevent cognitive decline late in life.

Despite marketing claims for “brain diets,” “brain games” and other interventions, a thorough analysis of all published research shows that diet, drugs, cognitive training, exercise, vitamins or supplements do not prevent Alzheimer’s disease or related types of dementia in people older than 85.

“There’s no magic bullet,” said Dr. Mary Butler, co-director of the Minnesota Evidencebased Practice Center, which conducted the

analysis and guides federal policy recommendations. The research, funded by the U.S. Agency for Healthcare Research & Quality, is published in Monday’s issue of the Annals of Internal Medicine.

There is an urgent need to prevent the brain disease that causes loss of memory, thinking and judgment. The number of Americans with either mild cognitive impairment or Alzheimer’s disease is expected to double by 2060 to 15 million, up from approximately 6.1 million this year.

Because there are no cures or even treatments to change progression of the disease, hopes have been pinned on prevention. Even delaying its onset would profoundly help, wrote Dr. Eric B. Larson of the Kaiser Permanente Washington Health Research Institute in Seattle, in an accompanying editorial.

The team analyzed the published evidence of 13 different types of interventions.

“We looked at drugs. We looked at over-the-counter vitamins and supplements. We looked at exercise. We looked at cognitive training. And overall, the results didn’t show much benefit,” said Dr. Howard Fink of the Minneapolis VA Health Care System.

A small minority of study results suggested potential benefits of a few small interventions.

For instance, when the researchers looked at the evidence for “cognitive training,” they found that people improved in the areas that they trained in — but did not improve in other areas. So while training may boost the time it takes for you to perform a mental task, that same training won’t help memory and other mental functions.

The only interventions that seemed promising are already goals of standard

“When people ask me how to prevent dementia … I tell them that they can take many common-sense actions that promote health throughout life.” — Dr. Eric B. Larson, Kaiser Permanente Washington Health Research Institute

medical care, such as regular physical activity, controlled blood pressure, healthy weight, quitting smoking and treating diabetes and other vascular risk factors.

“When people ask me how to prevent dementia, they often want a simple answer, such as vitamins, dietary supplements or the latest hyped idea,” wrote Larson.

“I tell them that they can take many commonsense actions that promote health throughout life.”

The reasons why these more hyped interventions fail aren’t entirely clear.

Perhaps the interventions were too short, or started too late in life. To prevent dementia, interventions may need to start when people are far younger, and continue for years. But such a lengthy study would be very expensive and pose major logistical challenges, said Butler.

Or maybe they just don’t work.

“It’s a humbling result,” said Fink. “It tells us that we have a lot to learn.”