Swedish study links residential greenery to lower dementia risk

Having more green spaces near home is associated with a 20% lower risk of developing dementia, according to a new study conducted by Stockholm University and the Karolinska Institutet in Sweden. The research was published in the journal Alzheimer’s & Dementia and involved nearly 3,000 participants, followed for sixteen years.

The most relevant finding concerns distance: the association between greenery and reduced risk was strongest for spaces located in the area closest to the home, within 100 meters, and progressively weakened as the distance from the home increased. This is an element the study’s authors indicate as central to understanding the mechanism behind the observed result.

This is an observational study on a cohort followed over time, not a controlled trial: the methodology allows for identifying a statistical association between the presence of greenery and dementia risk, but does not on its own demonstrate a direct causal link between the two factors. The sample of nearly 3,000 people, although followed over a long period, remains limited to the Swedish population studied, a factor that should be kept in mind when assessing the generalizability of the result to other geographic and social contexts, which differ in urban density, climate and lifestyle habits.

The study’s lead researcher, Cecilia Stenfors, indicated that the immediate environment around the home is a relevant factor for the conditions that support brain health over the long term, according to the journalistic account of the study. The study does not clarify, in this summary, which biological or behavioral mechanisms link proximity to greenery to a lower risk: the most commonly cited hypothesis in the field concerns the possible reduction of stress and the encouragement of physical activity, but this remains an interpretation to be verified, not a fact demonstrated by the research itself.

The authors did not disclose, in the released summary, whether the study declared any conflicts of interest related to its funding, information that remains to be verified in the full publication in Alzheimer’s & Dementia. At present the news comes from a single journalistic source reporting on the published study; no further independent confirmations are available.