Toronto, Jul 22 (IANS): Severe flu doubles the odds of your developing Parkinson's disease later in life, say researchers.

However, the reverse holds true for those who got infected with red measles as children. They are 35 percent less likely to develop Parkinson's, a nervous system disorder marked by slowness of movement, shaking, stiffness, and in the later stages, loss of balance.

The findings from the University of British Columbia (UBC's) School of Population and Public Health and the Pacific Parkinson's Research Centre are based on interviews with 403 Parkinson's patients and 405 healthy people in Canada.

Anne Harris from UBC who led the study also examined whether occupational exposure to vibrations -- such as operating construction equipment -- had any effect on the risk of Parkinson's, according to an UBC statement.

"There are no cures or prevention programmes for Parkinson's, in part because we still don't understand what triggers it in some people and not in others," says Harris, who conducted the research while earning her doctorate at UBC.

In another study, published by the American Journal of Epidemiology, she and her collaborators reported that occupational exposure actually decreased the risk of developing the disease by 33 percent, compared to people whose jobs involved no exposure.

Meanwhile, Harris found that those exposed to high-intensity vibrations -- for example, by driving snow-mobiles, battle tanks or high-speed boats -- had a consistently higher risk of developing Parkinson's than people whose jobs involved lower-intensity vibrations (for example, operating road vehicles).

Parkinson's results when brain cells that make the neurotransmitter dopamine are destroyed, preventing the brain from transmitting messages to muscles. The disease typically strikes people aged over 50.