Neighborhoods near golf courses are often considered desirable locations, blending nature, leisure and nice views. However, a new study suggests that houses within a few miles of manicured fairways and greens may not be such hot property after all. There's more research that the upkeep of these green spaces poses a significant neurological health risk.
Setting out to see if there was a link between increased Parkinson's disease (PD) risk and living near a golf course, Barrow Neurological Institute and Mayo Clinic researchers conducted a population-based case-control study that is now garnering a lot of attention – both good and bad.
In the research, 419 PD cases and 5,113 matched controls were assessed, looking at 139 golf courses in southern Minnesota and western Wisconsin. After using an Odds Ratio (OR) statistical tool to adjust for variables such as age, sex, income, and location makeup (rural/urban), the numbers seemed to confirm the scientists' hypothesis.
They found that living within two miles (3.2 km) of a golf course was linked to 198% higher odds of developing PD, and between two to three miles (4.8 km) it remained high at 121%. Risk decreased around 13% with each mile (1.6 km) beyond that. And the risk was higher for residents near courses that also had drinking water from groundwater sources considered vulnerable to pesticide contamination.
In fact, the scientists found that people living near a golf course and accessing groundwater had almost twice the odds of developing PD than those with no greens close by. For those living near a course, groundwater supply increased their chances of PD by around 50%, compared to people who had other, private water sources.
Now, these stats certainly sound like cause for concern. US golf course greenskeepers have a significantly higher reliance on pesticides than those in other parts of the world, and hundreds of chemicals have been identified to be in frequent use. Studies going back nearly a decade have shown that groundwater has varying degrees of pollution below and surrounding golf courses.
And golf courses have already been linked to another neurological disorder, Amyotrophic Lateral Sclerosis (ALS), which University of Michigan Medicine researchers identified in a 2024 paper.
However, this latest study has attracted pushback from the science community, noting the significant limitations of the research. These issues include how address-based exposure estimates only accounted for two to three years of living near a course before PD diagnosis, not lifelong exposure. This is particularly important given that PD can take much longer to develop. Also, the study used historical PD and address data from 1991–2015, however, only used 2013 golf course data, and the scientists did not look at other PD factors such as trauma and genetics.
“This study suggests an association between pesticides and Parkinson’s, however, there are some important limitations in the methodology to be aware of," explained Professor David Dexter, Director of Research at Parkinson’s UK. "Firstly, Parkinson’s starts in the brain 10-15 years before diagnosis and the study didn’t only use subjects who permanently lived in the area. This would not only affect participants’ exposure, but also suggests their Parkinson’s could have started before they moved around a golf course.
"The population was also not matched for location with 80% of the Parkinson’s subjects living in urban areas, compared to only 30% of controls, hence other factors like air pollution from motor vehicles etc could also account for some of the increases in Parkinson’s incidence," he added. "Additionally, no analysis was made of the drinking water for pesticide levels. Once again, this lessens the validity of the claim of pesticide exposure because the studies have not been carefully controlled.”
So while causation has not been shown, evidence of association is also thin on the ground, thanks to experimental design. While there may very well be a link between golf courses, pesticides and PD, more robust research is needed.
“Parkinson’s is complex," said Dr Katherine Fletcher, Research Lead at Parkinson’s UK. "The causes of the condition are unclear and are likely to involve both genetic and environmental factors. Many studies have investigated whether pesticides increase the risk of developing Parkinson’s in different populations around the world. The results have been varied, but overall suggest that exposure to pesticides may increase the risk of the condition.
"However, the evidence is not strong enough to show that pesticide exposure directly causes Parkinson’s," she continued. "This study supports the association between pesticides and Parkinson’s. However, it’s quite reductive and doesn’t take into account how someone might have been exposed to pesticides at their workplace or whether they have a genetic link to the condition."
The research was published in the journal JAMA Network Open.
Source: Barrow Neurological Institute via MedicalExpress
