Living in the country or near a city park can reduce the rate of age-related mental decline, research has shown.
Access to green space improved brain ageing in a group of more than 60,000 Britons who were monitored for 10 years, scientists found.
The effect was most marked among women, said the researchers, who estimated the amount of neighbourhood green space for each participant using satellite images.
Lead scientist Carmen de Keijzer, from the Barcelona Institute for Global Health, in Spain, said: “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 neighbourhoods.
“Interestingly enough, the observed associations were stronger among women, which makes us think that these relations might be modified by gender.”
All the participants were enrolled into the Whitehall II study tracking the health progress of a large group of UK civil servants.
At three different time points, each participant was asked to complete a battery of tests that assessed verbal and mathematical reasoning, verbal fluency and short-term memory.
The study built on evidence that the risk of dementia and mental decline can be affected by urban environmental hazards such as air pollution and noise, as well as stress and sedentary lifestyle.
“Living near green spaces has been proposed to increase physical activity and social support, reduce stress, and mitigate exposure to air pollution and noise,” said Ms de Keijzer.
“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.”
The findings appear in the journal Environmental Health Perspective.
Ms de Keijzer pointed out that the proportion of people in the world over 60 years of age is expected almost to double between 2015 and 2050. The number of global dementia cases is predicted to grow at a similar rate.
She added: “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.”