December 2, 2010

scientists comment on a study in a BMJ specialist journal that suggests long term exposure to pesticides may be linked to dementia

A study, published in Occupational and Environmental Medicine, looked at the neurobehavioral effects of long-term exposure to pesticides as a 4-year follow-up of the PHYTONER study.

Prof Robert Smith, Visiting Professor, University of Leeds, said:

“”It’s worth pointing out that low cognitive performance is affected by all sorts of factors and association does not mean causality. This study does not look at dementia and the link made here is so tenuous as to be sensationalised, especially from such a small study.””

Dr Simon Ridley, Head of Research, Alzheimer’s Research Trust, said:

“”It is important to note that this study is not showing that pesticide exposure causes dementia. The research suggests that people exposed to pesticides for long periods through work perform lower on some cognitive tests, but there are other factors that could explain the results. Determining any environmental risk factor for dementia is difficult and needs long term follow up, so we cannot yet draw any conclusions on whether pesticides affect dementia risk.

“It’s likely that many factors come in to play to determine whether someone develops dementia. Age is the biggest risk factor for dementia, but we know that our genes and environment also have a role. Further studies into risk are essential to allow us improve our protection from dementia, but research is drastically underfunded.””

Prof John Hardy, Professor of Neuroscience, UCL (University College London), said:

“”This is an interesting study but worth noting it is small numbers only a small effect and of course many studies show ‘effects’. Definitely a case of much more research needed!””