Scientists: Brain Use Slows Deterioration

W A S H I N G T O N, July 25, 2000 -- The brain is like a muscle: Use it or lose it.

That’s the growing conclusion of research that shows foggedmemory and slowed wit are not inevitable consequences of gettingold, and there are steps people can take to protect their brains.

Mental exercise seems crucial. Benefits start when parents readto tots and depend heavily on education, but scientists say it’snever too late to start jogging the gray matter.

People have to get physical, too. Bad memory is linked to heartdisease, diabetes and a high-fat diet, all risks people can counterby living healthier lives.

Increasing Protective Factors

In fact, provocative new research suggests thesebrain-protective steps, mental and physical, may be strong enougheven to help influence who gets Alzheimer’s disease.

“There are some things that, if you know you have a familyhistory [of Alzheimer’s] and you’re just 20 to 30 years old, youcan start doing to increase your protective factors,” said Dr.Amir Soas of Case Western Reserve University Medical School inCleveland.

It’s also good advice for the average baby boomer hoping to staysharp, or the mom priming her child for a lifelong healthy brain.

Most important: “Read, read, read,” Soas said. Do crosswordpuzzles. Pull out the chessboard or Scrabble. Learn a foreignlanguage or a new hobby. “Anything that stimulates the brain tothink,” he said.

And cut back on TV, Soas insists. “When you watch television,your brain goes into neutral,” he said. So much so that CaseWestern plans to study whether people who contract Alzheimer’swatched more TV throughout life than healthy seniors.

Brain Rewiring

The stereotype of the forgetful grandma has its roots innow-outdated dogma. Just a few years ago, scientists believed thebrain was wired forever before age 5, and that over the ensuingdecades a person irrevocably lost neurons and crucial braincircuitry until eventually mental decline became noticeable.

Not quite. Scientists now know the brain continually rewires andadapts itself, even in old age; large brain-cell growth continuesinto the teen years; and even the elderly can grow at least somenew neurons.

So cognitive decline doesn’t have to be inevitable. Indeed,mental tests given for 10 years to almost 6,000 older people found70 percent maintained brain power as they aged, lead researcherMary Haan of the University of Michigan told an internationalAlzheimer’s meeting this month.

What keeps brains healthy? Clues come from Alzheimer’s research.

Increased Intellectual Activity

Case Western scientists studied 550 people and found those lessmentally and physically active in middle age were three times morelikely to get Alzheimer’s as they grayed. Particularly protective:increasing intellectual activity during adulthood.

Numerous studies show people with less education have higherrisks of Alzheimer’s than the better-educated. Haan found less thana ninth-grade education a key threshold; other studies suggest adifference even between holders of bachelor’s and master’s degrees.

It’s not just formal education. Reading habits between ages 6and 18 appear crucial predictors of cognitive function decadeslater, said Dr. David Bennett of Chicago’s Rush University. Thetheory: Challenge the brain early to build up more “cognitivereserve” to counter brain-damaging disease later. Bennett ispreparing to test that by counting neurons in autopsied brains.

And remember that brain-muscle analogy? Brain scans showmentally “exercising,” which London cabbies do while navigatingwithout a map or pianists do when practicing, makes regions usedfor those intellectual challenges grow, while less-used areasshrink.

But physical health is important, too. A healthy brain needslots of oxygen pumped through healthy arteries. Haan studied peoplewho have a gene called ApoE4, which significantly increases therisk of Alzheimer’s. Brain function of gene carriers declined fourtimes faster with age if they also had hardened arteries ordiabetes. High-fat diets increased the risk seven times, CaseWestern researchers found.

That means exercising and eating right — the very things thatprevent heart disease and diabetes — helps the brain, too. And Haansaid it spotlights the next research frontier: Testing whethercholesterol and blood pressure treatments might prevent dementia.Stay tuned.