How to Keep Your Aging Brain Fit: Aerobics
How to Keep Your Aging Brain Fit: Aerobics
Forget Crossword Puzzles — Study Says
3 Hours of Exercise a Week
Can Bolster Memory, Intellect
The key to keeping intellectually sharp as we age may not be mental
gymnastics, as commonly recommended, but real gymnastics.
According to a new study, the brain’s long, slow decline may not be
inevitable. For the first time, scientists have found something that
not only halts the brain shrinkage that starts in a person’s 40s,
especially in regions responsible for memory and higher cognition,
but actually reverses it: aerobic exercise. As little as three hours
a week of brisk walking — no Stairmaster required — apparently
increases blood flow to the brain and triggers biochemical changes
that increase production of new brain neurons.
As brains age, normal wear and tear starting in middle age causes
them to process information more slowly, which means it takes longer
to make judgments and grasp complex information. Older brains also
take longer to switch from one task to another and are less adept at
“multitasking” (such as driving while simultaneously tuning the radio
and checking the tailgater).
The search for ways to slow down mental decline and detrimental brain
changes that come with age has taken an unexpected turn lately.
Popular wisdom, as well as some scientists, had long held that the
way to stay mentally sharp was to do mental gymnastics. Crossword
puzzles, reading, taking up a musical instrument, and generally
challenging the mind were supposed to stave off the mental ravages of
old age.
That has been hard to prove. But support for the brain benefits of
physical exercise has become stronger. A number of earlier studies
showed that elderly people who take up aerobic exercise show improved
cognitive function after a few months, says Arthur Kramer of the
University of Illinois, Urbana: Their working memory is better, they
are nimbler at switching between mental tasks, and they can screen
out distractions better than people who did not get exercise training.
Now he and colleagues have discovered what may be the basis for these
improvements. As little as three hours a week of aerobic exercise
increased the brain’s volume of gray matter (actual neurons) and
white matter (connections between neurons), they report in the
November issue of the Journal of Gerontology: Medical Sciences.
“After only three months,” says Prof. Kramer, “the people who
exercised had the brain volumes of people three years younger.”
Until 1998, neuro-dogma held that old brains do not grow new neurons.
A study on patients in Sweden overturned that assumption. But
researchers did not know whether people could do anything to boost
this “neurogenesis,” or even whether doing so would have cognitive
benefits. The Illinois study is therefore the first to discover that
older brains can indeed rev up their production of new neurons (no
one has studied whether younger brains can), and it is apparently
enough to make a real-world difference. Studies in both people and
animals have linked increases in brain volume (which occur with some
drugs) to improvements in thinking, remembering, cognitive
flexibility (thinking outside the box) and perseveration (not getting
stuck on one thought).
“This is a great emerging story,” says Fred Gage of the Salk
Institute, La Jolla, Calif., who was not involved in the Urbana study
but led the 1998 discovery of human neurogenesis. “You can do
something to influence your mental fate as you get older.”
The Urbana scientists had 59 adults, age 60 to 79,:
get aerobics training,
non-aerobic stretching-and-toning training,
or nothing.
