AM - Thursday, 7 April , 2005 08:16:00 Reporter: Kirstin Murray TONY EASTLEY: With the help of medical science Australians are starting to live longer, but one of the side effects is that our bodies are sometimes outliving our brains. 24 per cent of people aged over 85 will develop dementia for which there's no cure.
But new research is looking at exercise as a way of increasing our longevity and retaining cognitive activity. One Queensland-based scientist hopes to reduce the risk of developing degenerative conditions such as Alzheimer's and Parkinson's disease. And he's proven that exercise doesn't just keep your body fit.
Kirstin Murray reports.
KIRSTIN MURRAY: By the end of this year another 52,000 Australians will be diagnosed with dementia, a mental disorder which eventually causes severe memory loss. But recent tests on mice have found there may be a way to stop brain cells deteriorating and possibly stave off degenerative conditions.
Professor Perry Bartlett from the University of Queensland's Brain Institute says the key is to encourage brains to make new cells for themselves and then nurture them, just like a young, healthy brain would.
PERRY BARTLETT: These new nerve cells are really quite vital to our ability to function in the higher brain functions, such as memory and learning. So we think that the constant replacement and selection of new neurons fundamentally underlies our ability to continue to have a functional brain.
KIRSTIN MURRAY: Stroke victims could also benefit where new cells would replace those lost.
But to succeed, Professor Bartlett says cells have to be stimulated, and the more encouragement they're given, the better they work.
PERRY BARTLETT: That's right, most of them die. We now know that we can preserve some of them by giving direct stimuli. Quite prolonged exercise is very good to make new neurones.
Perhaps doing something a little more inquisitive or intellectual might be good at selecting their survival. So perhaps one should run a long distance and do the cryptic crossword or something like that.
KIRSTIN MURRAY: It's easy to understand how mental stimulation could help these cells. How can physical activity help them as well?
PERRY BARTLETT: Well, that's a very interesting thing. There are a lot of hormones and changes in blood that go up and down after exercise, and so that may be a lead to some of the chemicals that can drive the production of nerve cells.
One of the chemicals that seems to promote neurogenesis is prolactin, and prolactin levels are very high in pregnant females. Prolactin levels, by the way, also go up during sex as well. So one could think of a number of more entertaining activities than running in order to regulate the production of nerve cells.
KIRSTIN MURRAY: For people who have already been diagnosed with dementia, would this research help them at all?
PERRY BARTLETT: If we understand these mechanisms we should be able to use them to treat neurodegenerative diseases, or even mental illnesses in the long-term. So, they're both aspects I think which are quite revolutionary in terms of understanding how our brain just normally maintains healthy function, but also in how we might be able to drive this system into treating disease.
TONY EASTLEY: Professor Perry Bartlett from the University of Queensland, ending that report from Kirstin Murray.
Professor Perry Bartlett of University of Queensland's Brain Institute recommends sex, cryptic crosswords and a good run to stave off dementia.

The researcher, interviewed on Australian ABC radio today , said that with 52,000 Australians expected to be diagnosed with dementia by the end of the year, people wishing to ward off the degenerative disorder may benefit from activities which stimulate growth of new cells in the brain, accompanied by mental exercise to select for survival of the resulting crop of new cells.

"Quite prolonged exercise is very good to make new neurones," said the Professor. "These new nerve cells are really quite vital to our ability to function in the higher brain functions, such as memory and learning. Most of them die. We now know that we can preserve some of them by giving direct stimuli."

Professor Bartlett explained recent research findings, including those from collaborator Jeffrey D. Macklis  at Harvard in the US.

"There are a lot of hormones and changes in blood that go up and down after exercise, and so that may be a lead to some of the chemicals that can drive the production of nerve cells.

"One of the chemicals that seems to promote neurogenesis is prolactin, and prolactin levels are very high in pregnant females. Prolactin levels, by the way, also go up during sex as well. So one could think of a number of more entertaining activities than running in order to regulate the production of nerve cells.

"Perhaps doing something a little more inquisitive or intellectual might be good at selecting their survival. So perhaps one should run a long distance and do the cryptic crossword or something like that," he said.

Professor Bartlett gave the same suggestions as being potentially helpful in depression, last year in an interview on the ABC ''Science Show''.