Scientists link Parkinson's with specific pesticide

| 14th July 2009
Blood samples
Beta-HCH may be a factor in the development of Parkinson's. Its presence in the blood could be a test for the disease
Tests on Parkinson's sufferers have revealed a high incidence and levels of the organochloride pesticide beta-HCH, holding out the hope of a blood test to catch the disease early

Scientists in the US believe they have found a link between a specific organochloride pesticide and Parkinson’s disease.

A study of 113 people – 50 of whom had Parkinson’s, 20 Alzheimer’s and 43 of whom were healthy – revealed that beta-hexachlorocyclohexane (HCH) was unusually prevalent in Parkinson’s patients, and in unusually high doses.

Scientists at the University of Texas Southwestern Medical Center in Dallas were testing for traces of 15 organochloride pesticides. Published in the journal Archives of Neurology, their research is the first to make a definite link between the progressive degenerative disease and a particular pesticide.

Beta-HCH was found in 76 per cent of the Parkinson’s sufferers tested, 40 per cent in healthy people and 30 per cent in Alzheimer’s sufferers. Organochloride pesticides were widely used from the 1950s to the 1970s.

A possible explanation for the presence of beta-HCH could be found in the genetic make-up of some people, whose metabolism is such that it is harder for their bodies to break down certain substances. Another possibility is that the presence of the pesticide is a marker of another harmful chemical. The researchers said pesticides were only one contributing factor in the development of the disease.

‘There's been a link between pesticide use and Parkinson’s disease for a long time, but never a specific pesticide,’ said lead researcher Professor Dwight German. ‘This is particularly important because the disease is not diagnosed until after significant nerve damage has occurred.

‘Much higher levels of the beta-HCH were in the air, water and food chain when the Parkinson's patients were in their 20s and 30s… also the half-life of the pesticide is seven to eight years, so it stays in the body for a long time.’

The findings hold out the hope that it may be possible to identify those susceptible to Parkinson’s by performing a simple blood test.


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