Tuesday, 11 September 2007

Exercise key to fit brain, body

MEDICAL research keeps proving a phrase that’s become a cliché – use it or lose it.
And eat a healthy balanced diet.
It may not be rocket science, but it is brain science.
“It’s the same old message really,” says David Bilkey (right), of Otago University.
“We know exercise has been shown to promote neurogenesis, the growth of new neurons in the brain.”
Mental exertion is just as important.
The associate professor of psychology says that that studies show that people with higher education are less likely to be affected by Alzheimer’s, a disease that destroys the brain.
People who have studied or regularly “work” their brains make more synapses or connections in the brain,
Dr Bilkey says. “That reduces the chances of damage, or makes it (the brain) more resistant to damage.”
As we age, our brain plasticity, or flexibility to make new connections, lessens. When we’re young, especially prior to the age of five or six, and again at adolescence, our brains make and remake a huge number of connections.
Higher education promotes even further connections, Dr Bilkey says.
Imagine the connections as streets in a village, one that eventually becomes a massive city. That’s how the brain works.
So, people who continue to use their brains, train their minds, and keep learning, will end up with a brain resembling a metropolis with an intricate network of highways, main roads and side streets.
“As we age, we are losing connections between neurons and the ability to alter those connections, so we are having to work with fewer resources.”
So you might lose a few hundred motorways and a couple of thousand cul-de-sacs, but when you’ve got millions of others still firing the messages around, it’s not such a big loss.
But if you’re a village it’s not so good.
So, let’s head back into the big city; this time London.
Dr Bilkey, who specialises in location memory, is interested in the outcome of a study on taxi drivers in the British capital.
It shows that cabbies who have been on the job for a long time and who know how to navigate London with ease, have bigger brains. “The longer you work as a taxi driver, the larger your hippocampus is,” he says, about the area of the brain first affected in Alzheimer’s patients.
The size increase is simply because the cabbies have an improved capacity to remember information about locations and navigation.
Birds who cache their food in many different places, which they later must return to, also have increased brain size in the part equivalent to the human hippocampus, Dr Bilkey says.
He believes people need to think of their brain as being a muscle. “If you use it, it will get larger and better, and if you don’t, it will atrophy.”
Muscles also waste away when they’re not used – as many people who’ve had a limb in plaster will know.
The same happens to anybody who doesn’t exercise, especially ageing people who decide they’re too old to keep going.
Garth Gilmour (right), a former journalist and the author of 21 books on sportspeople and fitness, implores people to keep going.
His big message is this: “The exercise you do should be will within your abilities to do and you need to enjoy it.”
He recommends walking, doing housework and gardening as simple ways to remain fit. “Stay away from gymnasiums,” he says.
But always head for steps. “My wife and our love our stairs,” he says, citing why he keeps living in a two-storey house, while other elderly people opt for units and no gardens.
The never-retired writer says using your brain is just as important as a physical work out. He tells people to read, do crosswords or other puzzles, plus talk and listen to people to remain mentally agile.
“Keep the mind moving, but sitting up, blobbing in front of the television isn’t exercising your brain. You are being dumbed down by TV.”

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