By Marie Ellis
It is well known that exercise is good for the mind and body, but to what extent does the neighborhood or community in which we live affect our physical and mental health? New research from the University of Kansas suggests the walkability of a community has a great impact on cognition in older adults.
Previous studies have detailed the importance physical exercise has for executive function in older adults.
But how can the layout of a neighborhood encourage its residents to get out and walk? This is precisely what Amber Watts, assistant professor of clinical psychology at the University of Kansas, wanted to find out.
"Depending on which type of walking [leisure vs. walking to get somewhere] you're interested in, a neighborhood might have different characteristics," she says. "Features of a neighborhood that encourage walking for transportation require having someplace worth walking to, like neighbors' houses, stores and parks."
She adds that neighborhoods that encourage leisure walking have "pleasant things to look at," including walking trails and trees, and they should feel safe.
Her research, which she presented yesterday at the Gerontological Society of America's annual meeting in Washington, DC, suggests that neighborhoods that encourage walking can protect against cognitive decline in older adults.
To conduct her research, Watts used geographic information systems (GIS) to judge walkability. This involved maps that measure and analyze spatial data.
Better physical and mental health
Detailing how she collected her data, Watts explains:
"GIS data can tell us about roads, sidewalks, elevation, terrain, distances between locations and a variety of other pieces of information. We then use a process called space syntax to measure these features, including the number of intersections, distances between places or connections between a person's home and other possible destinations they might walk to."
She also looked at how complicated a route is from one location to another: "For example, is it a straight line from point A to point B, or does it require a lot of turns to get there?"
To conduct the study, Watts and colleagues tracked 25 people with mild Alzheimer's disease and 39 older adults without any cognitive impairment. Using the space syntax data, they created a "walkability score" for the participants' home addresses.
Then, they estimated the relationship between a person's neighborhood scores and how well they performed on cognitive tests over 2 years. The cognitive tests included three categories: attention, verbal memory and mental status. The team also factored in issues that might influence cognitive scores, including age, gender, education and wealth.
Results from the study suggest that communities that are easier to walk in are linked to better physical health outcomes - such as lower body mass and blood pressure - and cognition - including better memory.
Watts and her colleagues believe their findings could benefit older adults, health care professionals, caregivers and even architects and urban planners.
Do mentally complex neighborhoods act like a brain-training game?
Though elaborate community layouts may be expected to confuse older residents, Watts and her team found that they actually serve to keep cognition sharp.
"There seems to be a component of a person's mental representation of the spatial environment, for example, the ability to picture the streets like a mental map," Watts says.
She adds that complicated environments may demand more intricate mental processes in order to navigate them, which could keep the mind sharp. This is in line with previous studies, which have demonstrated how staying mentally active helps to preserve memory.
"Our findings suggest that people with neighborhoods that require more mental complexity actually experience less decline in their mental functioning over time," Watts adds.
She explains that a challenging environment keeps an individual's body and mind healthy:
"With regard to the complexity of neighborhood street layouts - for example, the number of turns required getting from point A to point B - our results demonstrate that more complex neighborhoods are associated with preserved cognitive performance over time.
We think this may be because mental challenges are good for us. They keep us active and working at that optimal level instead of choosing the path of least resistance."
A National Institute on Aging grant, KU Strategic Initiative Grant and Frontiers Clinical Translational Science award helped fund the study.