Alzheimer's and Parkinson's risk reduced by nature exposure

US researchers have discovered a potential link between exposure to some types of natural environments and a lower risk of developing Alzheimer’s and Parkinson’s Disease, according to research published in JAMA Network Open.

The team evaluated data from the US Medicare program from 2000–2016 to consider hospitalisations relating to Alzheimer’s disease and related dementias (ADRD) and Parkinson’s disease (PD) in two groups of 60 million patients.

This data was compared with the amount of greenery, park space and blue space — waterways such as lakes, ponds and rivers — in the vicinity of the person’s home.

Overall, the researchers concluded that all three types of nature exposure were associated with a decreased risk of Parkinson’s hospitalisations. More green space was associated with a lower risk of Alzheimer’s.

Associations with greenness and Parkinson’s or Alzheimer’s related dementias remained after adjustment for pollutants. Authors of the study highlighted other factors that could contribute to the benefit of nature exposure including stress reduction, attention restoration, increased physical activity and social interactions. They also cited studies referencing natural environments and a reduced risk of cardiometabolic disease or depression, which has been linked to an increased risk of Alzheimer’s and Parkinson’s Disease.

The study authors said, “As life expectancy increases globally, policymakers should consider interventions of natural environments to prevent ADRD and PD.”

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