Nature's shield – Harnessing green spaces to combat dementia: A global meta-analysis

As global aging populations increase, dementia is one of the fastest-growing global public health challenges across multiple sectors. About 10 % of the population aged 65 years and older are affected by some form of dementia without adequate medical treatment to cure, so finding practical approaches for the prevention, intervention, and care of dementia is urgent. With multiple health benefits, green spaces provide therapeutic functions as nature-based solutions for people with dementia. The meta-analysis and comprehensive review have revealed a beacon of hope through a search of six databases from 2009 to 2024 and the identification of 37 eligible studies. Results showed that urban green spaces, particularly those featuring community gardens, significantly impacted individuals with dementia and the older population. The results, which showed a significant effect size correlation in four key areas: individual ability, social interaction, mental stress, and emotional health, highlight the positive impact of these green spaces. The specific performance of these green spaces is as follows: reduced incidence of dementia (-0.06), improved social participation (0.14), increased physical isolation (0.54), reduced anxiety (-0.28), relieved depression, relieved mental disorders (-0.32), calmed agitation (-0.06), increased positive emotions (0.10), reduced sadness and anger, improved quality of life, enhanced cognitive function (0.52), and improved sleep. Finally, the mechanisms of green spaces' influence on the health of people living with dementia, including the perception of green spaces contact, intermediary pathway, and health effects, provide a compelling argument for implementing urban green spaces coupled with ecosystem services as a pragmatic approach to improving the mental health and overall well-being of older people and those with dementia. Such initiatives not only contribute to the prevention of dementia by addressing multiple, simultaneous alterations to avert and combat it but also align with the broader goals of achieving sustainable development.