Long term exposure to pesticides may be linked to dementia

December 01, 2010

Long term exposure to pesticides may be linked to the development of dementia, suggests research published online in Occupational and Environmental Medicine.

The authors base their findings on 614 vineyard workers in South West France whose intellectual capacity was monitored for up to six years as part of the PHYTONER study.

This aims to track the impact of pesticides on the cognitive abilities of people in their 40s and 50s who have worked for at least 20 years in the agricultural sector.

Levels of exposure to pesticides were based on job calendars and categorised as 'directly exposed' (mixing or applying pesticides, cleaning or repairing spraying equipment); 'certainly indirectly exposed' (contact with treated plants); 'possibly indirectly exposed' (work in buildings, offices, cellars); and 'not exposed' if they had done none of the above.

Just under 1000 workers enrolled in the study between 1997 and 1998, 614 of whom were monitored between 2001 and 2003. On both occasions they completed a questionnaire and nine "neurobehavioural" tests designed to measure memory and recall; language retrieval and verbal skills; and reaction time speeds.

One in five had never been exposed to pesticides as part of their job; over half had been directly exposed, and the remainder had been possibly or certainly indirectly exposed.

Not unexpectedly, lower scores in some or all of the cognitive tests were associated with older age, lower levels of education, excessive alcohol intake, depression, and drug-taking on both occasions.

Around a fifth to half of the workers obtained higher scores in some of the tests; 15% to half obtained lower test scores over time, depending on the test.

But with the exception of two of the nine tests, those who had been exposed to pesticides were the most likely to perform worse second time around.

These workers were up to five times as likely to obtain lower test scores on both occasions, and they were twice as likely to register a drop of two points in the mini mental state exam (MMSE) - the initial test frequently used to determine if a person has dementia.

This decline in MMSE score "is particularly striking in view of the short duration of follow up and the relatively young age of the participants," say the authors, who add that previous research has already reported an association between pesticide exposure and poor performance for several of the tests used in this study.

"The mild impairment we observed raises the question of the potentially higher risks of injury in this population and also of the possible evolution towards neurodegenerative diseases such as Alzheimer's disease or other dementias," they say.

And they add: "Numerous studies have shown that low cognitive performances are associated with risk of dementia."
-end-


BMJ

Related Dementia Articles from Brightsurf:

The danger of Z-drugs for dementia patients
Strong sleeping pills known as 'Z-drugs' are linked with an increased risk of falls, fractures and stroke among people with dementia, according to new research.

The long road to dementia
Alzheimer's disease develops over decades. It begins with a fatal chain reaction in which masses of misfolded beta-amyloid proteins are produced that in the end literally flood the brain.

Why people with dementia go missing
People with dementia are more likely to go missing in areas where road networks are dense, complicated and disordered - according to new research from the University of East Anglia.

PTSD may double risk of dementia
People who have experienced post-traumatic stress disorder (PTSD) are up to twice as likely to develop dementia later in life, according to a new study by UCL researchers, published in the British Journal of Psychiatry.

Dementia education
School-based dementia education could deliver much needed empathy and understanding for older generations as new research from the University of South Australia shows it can significantly improve dementia knowledge and awareness among younger generations.

Building dementia friendly churches
A project to help church communities become more 'dementia friendly' has had a significant impact across the country.

A "feeling" for dementia?
A research team led by the DZNE concludes that personal perception can be an important indicator for the early detection of Alzheimer's disease.

New biomarker for dementia diagnosis
Medical researchers in the UK and Australia have identified a new marker which could support the search for novel preventative and therapeutic treatments for dementia.

Digital solutions for dementia care
Telehealth delivery of dementia care in the home can be as effective as face-to-face home visit services if carers and recipients take advantage of the technologies available, Australian researchers say.

Despite a marked reduction in the prevalence of dementia, the number of people with dementia is set to double by 2050 according to new Alzheimer Europe report
Today, at a European Parliament lunch debate, Alzheimer Europe launched a new report presenting the findings of its collaborative analysis of recent prevalence studies and setting out updated prevalence rates for dementia in Europe.

Read More: Dementia News and Dementia Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.