Association between Parkinson's Disease and Cigarette Smoking, Rural Living, Well-Water Consumption, Farming and Pesticide Use: Systematic Review and Meta-Analysis
Breckenridge CB, Berry C, Chang ET, Sielken RL, Mandel JS
PloS one · 153 citations
Review labels
Neutral facts our review recorded about how this study was done. They describe method, never whether we like the result.
How it was studied
- Design
- Meta-analysis (indexed by PubMed)
- Studied in
- People
- Main outcome
- Clinical events such as disease or death
Who paid for it
- Funding
- Industry funded
- Authors
- At least one author declares a financial tie to industry
Based on full-text disclosure statement.
Publication
- Published
- 2016-04-07 · PLoS One · vol. 11 · issue 4 · p. e0151841
- Publisher
- Public Library of Science
- Cited
- 251 citations · more than 97% of similar papers · 4.5× the field average
- Impact
- Top 10% most cited in its field
- References
- 212 works
- Access
- Open access (journal) · CC-BY
- Research areas
- Parkinson's Disease Mechanisms and Treatments · Pesticide Exposure and Toxicity · Amyotrophic Lateral Sclerosis Research
- Keywords
- Environmental health, Meta-analysis, Medicine, Relative risk, Agriculture, Confidence interval, Biology, Ecology, Pathology, Internal medicine
- MeSH
- humans, parkinson disease, pesticides, risk factors, smoking, agriculture, rural population, water wells
5 authors
From US, GB
- Charles B. Breckenridge · correspondingSyngenta (United States)
- Colin Berry · correspondingQueen Mary University of London
- Ellen T. Chang · correspondingExponent (United States); Menlo School
- Robert L. Sielken · corresponding
- Jack S. Mandel · correspondingExponent (United States); Menlo School
Abstract
Objective
Bradford Hill's viewpoints were used to conduct a weight-of-the-evidence assessment of the association between Parkinson's disease (PD) and rural living, farming and pesticide use. The results were compared with an assessment based upon meta-analysis. For comparison, we also evaluated the association between PD and cigarette smoking as a "positive control" because a strong inverse association has been described consistently in the literature.
Methods
PubMed was searched systematically to identify all published epidemiological studies that evaluated associations between Parkinson's disease (PD) and cigarette smoking, rural living, well-water consumption, farming and the use of pesticides, herbicides, insecticides, fungicides or paraquat. Studies were categorized into two study quality groups (Tier 1 or Tier 2); data were abstracted and a forest plot of relative risks (RRs) was developed for each risk factor. In addition, when available, RRs were tabulated for more highly exposed individuals compared with the unexposed. Summary RRs for each risk factor were calculated by meta-analysis of Tier 1, Tier 2 and all studies combined, with sensitivity analyses stratified by other study characteristics. Indices of between-study heterogeneity and evidence of reporting bias were assessed. Bradford Hill's viewpoints were used to determine if a causal relationship between PD and each risk factor was supported by the weight of the evidence.
Findings
There was a consistent inverse (negative) association between current cigarette smoking and PD risk. In contrast, associations between PD and rural living, well-water consumption, farming and the use of pesticides, herbicides, insecticides, fungicides or paraquat were less consistent when assessed quantitatively or qualitatively.
Conclusion
The weight of the evidence and meta-analysis support the conclusion that there is a causal relationship between PD risk and cigarette smoking, or some unknown factor correlated with cigarette smoking. There may be risk factors associated with rural living, farming, pesticide use or well-water consumption that are causally related to PD, but the studies to date have not identified such factors. To overcome the limitations of research in this area, future studies will have to better characterize the onset of PD and its relationship to rural living, farming and exposure to pesticides.
Abstract via Europe PMC. Copyright remains with the authors or publisher (CC BY).
Community trust
Loading…
How much do you trust this study's findings?
Comments
Sign in to rate, comment on or flag this study.Sign inSomething wrong here?
Flag this study if its information, labels or funding look wrong. An editor reviews every flag.
Sign in to rate, comment on or flag this study.Sign inEducational information about published research. Not medical advice, and not a recommendation to start or stop anything.