http://news.bbc.co.uk/2/hi/health/3309953.stm

BBC News

Infections 'could prolong life'

Scientists say a virus or a high temperature can actually be good for
you because they trigger body chemicals which can prolong cell life.

So a little physical stress, like a little red wine or chocolate, may
be beneficial.

Researchers writing in the journal Molecular Biology of the Cell say
bursts of stress "turns on" key genes which encode protective
molecules.

But they added that prolonged stress was not good.

Cell damage

Scientists from Northwestern University in Illinois, US, studied C.
elegans, a transparent roundworm whose biochemical environment is
similar to that of human beings.

They focused on heat shock factor, the master gene that controls the
expression of molecular chaperones, special protective chemicals that
respond to stress in a cell.

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An occasional burst of stress or low levels of stress can be very
protective -- Professor Richard Morimoto, Northwestern University
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Molecular chaperones "tidy up" damaged proteins in cells. Stress
triggers this reaction, prolonging life by preventing or delaying cell
damage.

The scientists found that when heat shock factor genes were
over-expressed, the worms' lifespan increased. But if they were
under-expressed, the opposite was true.

The researchers highlighted increased temperatures, oxygen stress,
bacterial and viral infections, and exposure to toxins such as heavy
metals as factors which could increase stress on cells.

Professor Richard Morimoto, who led the research, said: "Sustained
stress definitely is not good for you, but it appears that an
occasional burst of stress or low levels of stress can be very
protective.

"Brief exposure to environmental and physiological stress has
long-term benefits to the cell because it unleashes a great number of
molecular chaperones that capture all kinds of damaged and misfolded
proteins."

'Isolated effects'

Phil Evans, professor of psychology at the University o Westminster,
told BBC News Online: "Stress affects our minds and biological systems
so wholly and profoundly that there should be no problem in
acknowledging its influence.

"Acute stress leads to all sorts of potentially measurable effects on
our physical selves, and the problem is working out which isolated
effects may be significant in the round and in the longer term for
health."

"But there is, as the researchers acknowledge, lots of evidence that
chronic and severe long-term 'stress' is bad for health."

Story from BBC NEWS:
http://news.bbc.co.uk/go/pr/fr/-/2/hi/health/3309953.stm

Published: 2003/12/12 00:17:18 GMT
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