STEVE INSKEEP, Host:
NPR's Jon Hamilton says many scientists are still optimistic about prevention, partly because they're also considering research done on animals.
JON HAMILTON: At about the time the panel was releasing its report, a 78-year- old senator was doing something he hopes is good for his brain.
U: And here comes Senator Richard Lugar, 29 times in a row.
(SOUNDBITE OF CHEERING AND APPLAUSE)
U: Running strong after 29 years.
HAMILTON: Lugar was competing in an annual charity race a few miles from Capitol Hill. He's been a runner since grade school, and thinks exercise helps him remember a lot of stuff.
INSKEEP: The names and places of thousands of people and events that I bring up frequently in the course of debate. It's very helpful to have that kind of historical knowledge of my constituency, as well as of the world.
HAMILTON: Arthur Kramer, a neuroscientist from the University of Illinois, wasn't on the panel, though he was invited to speak to the group. He says the panel is right to be cautious. But he says there are reasons researchers talk about the potential of exercise.
INSKEEP: The benefits tend to be on the order of a 20 to 30 percent reduction in being diagnosed with Alzheimer's disease and other such diseases. Then again, this isn't universal, but this is found in increasing number of studies.
HAMILTON: Kramer says researchers also tend to consider studies that show what exercise does for animals.
INSKEEP: There are improvements in the chemistry of the brain, in terms of the molecules that protect the brain; increases in the number of connections between neurons; and even the birth of new neurons in one region of the brain that supports memory.
HAMILTON: But Neil Buckholtz, from the National Institute on Aging, says the panel would need a lot more than that to recommend a specific activity to the public.
D: Doing crossword puzzles or Sudoku, those kinds of things. They're interesting, but the evidence is not available at this point that they actually have an effect.
HAMILTON: Martha Clare Morris is less skeptical. She's a nutritional epidemiologist at Rush University Medical School in Chicago, who was invited to speak to the panel. Morris says there is good evidence that some antioxidants work - in animals.
D: There's a very broad base of animal models to show that Vitamin E protects the brain from neuron loss, from DNA damage, from oxidative damage.
HAMILTON: Jon Hamilton, NPR News.
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