Living in green spaces can guard against mental decline, dementia

Living near green space has many positive effects, and studies have shown that urban green space specifically counters the negative impacts of city pollution.

Now, a new study found that living in greener neighborhoods may also potentially guard against cognitive decline and decrease the risk of dementia among the elderly.

Researchers from the Barcelona Institute for Global Health (ISGlobal) conducted the study which was published in the journal Environmental Health Perspectives.

The results show that cognitive decline, a natural indicator of the aging process, slows down slightly among people who live near green space.

“There is evidence that the risk for dementia and cognitive decline can be affected by exposure to urban-related environmental hazards (such as air pollution and noise) and lifestyle (such as stress and sedentary behavior),” said Carmen de Keijzer, the study’s first author. “Recent evidence has shown cognitive benefits of green space exposure in children, but studies on the possible relations of exposure to green spaces and cognitive decline in older adults are still very scarce and often have inconsistent results.”

For the study, the researchers followed up on 6,500 people ages 45 to 68 who were part of the UK Whitehall II Cohort Study after ten years.

The participants were asked to complete a course of cognitive tests to measure verbal fluency, short-term memory, and mathematical reasoning at three different points during the follow-up.

In order to see if greenspace influenced the test results, the researchers used satellite imagery to estimate how much green space the study participants were in proximity to.

The results showed that there was a slight but definite influence with green space slowing cognitive declines.

“Our data show that the decline in the cognitive score after the 10-years follow up was 4.6% smaller in participants living in greener neighborhoods,” said Keijzer. “Interestingly enough, the observed associations were stronger among women, which makes us think that these relations might be modified by gender.”

The results are significant as the researchers say that the number of dementia cases is expected to double between 2015 and 2050.

“Although the differences in cognitive decline observed in our study are modest at individual level, they become much more significant if we consider these findings at population level,” said Payam Dadvand, the last author of the study. “If confirmed by future studies, our results may provide an evidence base for implementing targeted interventions aimed at decelerating cognitive decline in older adults residing in urban areas and hence improving their quality of life.”

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By Kay Vandette, Earth.com Staff Writer

Image Credit: Huy Phan