Washington The brain is like a muscle: Use it or lose it.
That's the growing conclusion of research that shows fogged memory and slowed wit are not inevitable consequences of getting old, and there are steps people can take to protect their brains.
Mental exercise seems crucial. Benefits start when parents read to tots and depend heavily on education, but scientists say it's never too late to start jogging the gray matter.
People have to get physical, too. Bad memory is linked to heart disease, diabetes and a high-fat diet, all risks people can counter by living healthier lives.
In fact, provocative new research suggests these brain-protective steps, mental and physical, may be strong enough even to help influence who gets Alzheimer's disease.
"There are some things that, if you know you have a family history (of Alzheimer's) and you're just 20 to 30 years old, you can start doing to increase your protective factors," said Dr. Amir Soas of Case Western Reserve University Medical School in Cleveland.
It's also good advice for the average baby boomer hoping to stay sharp, or the mom priming her child for a lifelong healthy brain.
Most important: "Read, read, read," Soas said. Do crossword puzzles. Pull out the chessboard or Scrabble. Learn a foreign language or a new hobby. "Anything that stimulates the brain to think," he said.
And cut back on TV, Soas insists. "When you watch television, your brain goes into neutral," he said. So much so that Case Western plans to study whether people who contract Alzheimer's watched more TV throughout life than healthy seniors.
The stereotype of the forgetful grandma has its roots in now-outdated dogma. Just a few years ago, scientists believed the brain was wired forever before age 5, and that over the ensuing decades a person irrevocably lost neurons and crucial brain circuitry until eventually mental decline became noticeable.
Not quite. Scientists now know the brain continually rewires and adapts itself, even in old age; large brain-cell growth continues into the teen years; and even the elderly can grow at least some new neurons.
So cognitive decline doesn't have to be inevitable. Indeed, mental tests given for 10 years to almost 6,000 older people found 70 percent maintained brain power as they aged, lead researcher Mary Haan of the University of Michigan told an international Alzheimer's meeting this month.