Why not escape from all the hustle and bustle of life in an urban environment - and its toxic air - by taking a daily stroll through the park? Green spaces can keep you physically fit, lower stress, improve concentration, and benefit your mental health. But can they also ward off dementia?
According to a major new study, yes they can. Not only that, it’s the first study to show that even those with a higher genetic risk of Alzheimer's will reap the cognitive rewards of a green environment. Here’s what you need to know…
Key Takeaways
- Regular exposure to green environments can enhance cognitive function and reduce the rate of cognitive decline.
- The cognitive benefits of green spaces are particularly significant for those at high genetic risk of Alzheimer’s disease.
- Researchers believe exposure to green spaces can influence how certain genes related to Alzheimer’s are expressed.
Green Space Exposure and Your Health
Spending time in nature at any age works wonders for your health. Greenness exposure is linked with many important health benefits. We previously reported on its ability to reduce serious psychological distress, promote happiness, and even help you live longer.
While some studies show cognitive benefits, few have examined a large group of people without cognitive problems over time to see if there’s any difference between those living in a green environment and those who don’t.
To fill this research gap, a team from Harvard and the Rush Alzheimer's Disease Center, Chicago, carried out a study using the long-running Nurses’ Health Study.
Nature Improves Cognition
This started in 1976 and included married female nurses, aged 30–55, located across 11 U.S. states. For the current study, the team analyzed a sub-study of 16,962 nurses from 1995 through 2008.
The team used telephone surveys to assess five types of cognitive function and repeated the process up to four times over six years. Next, they measured greenness levels around participants’ homes via a satellite image-based metric up to nine years before the first cognitive survey.
After making statistical adjustments for age, socioeconomic factors, and others factors that might influence the findings, the Harvard team found higher exposure to a green environment during midlife was linked to higher levels of overall cognitive function. What’s more, those with the most green space exposure experienced a slower rate of cognitive decline, staving it off by an annual rate of eight months. Only verbal memory wasn’t influenced by greenness.
Greater Benefits for Lower Socioeconomic Status
The cognitive benefits were stronger among people living in highly populated neighborhoods in low socioeconomic status (SES) areas. This is consistent with the theory of equigenic environments, or to put it more clearly, leveling the playing field.
In other words, economically disadvantaged people have poorer health outcomes, but greenness can offset this. Although everyone benefits, the disadvantaged benefit even more.
Marcia Pescador Jimenez, who led the research said, “greenness might be important to reduce socioeconomic health inequities. The findings emphasize the importance of prioritizing the preservation and creation of green spaces, particularly in low-SES neighborhoods, as a means of promoting cognitive health later in life.”
While this adds to existing knowledge, what was fascinating was a finding that was unique and important to everyone’s health.
We Can Affect Our Genes With Green Spaces
While there’s a belief that we can do nothing about the genes we’re born with, that’s not the whole story. Although the APOE-ɛ4 gene is a major risk factor for Alzheimer's, the study findings showed that nurses carrying the gene who were exposed to more greenery had a threefold magnitude of slower cognitive decline compared to people without the gene. That’s a huge effect!
This was the first study to explore the relationship between greenness and cognition among carriers of the APOE-ɛ4 gene. The finding demonstrates that it’s not just about the genes we inherit but also the way they’re expressed, and this is influenced by our environment. This is called epigenetics.
Genes' structure remains the same, but their behavior relies on raw materials in their environment. And we have some control over this. Think of it like a perfect automobile engine. Put the wrong fuel in, and it won’t run properly, even though the engine hasn’t changed in any way.
The wrong fuel for a car is equivalent to poor dietary choices, bad sleep patterns, chronic stress, lack of exercise, and social isolation for the human body. Now, we can add lack of nature to the list. Working to improve all these factors will help prevent Alzheimer’s and many other health problems.
Summary
A recent study reveals that spending time in green spaces can significantly slow cognitive decline, even for those with a genetic predisposition to Alzheimer’s disease. This large-scale study conducted over 13 years shows that exposure to green environments is linked to better cognitive function and slower cognitive decline, particularly benefiting those from lower socioeconomic backgrounds. This research underscores the importance of green spaces in urban planning, as they can help mitigate genetic risks associated with dementia and contribute to overall cognitive health.
Frequently Asked Questions
- How do green spaces benefit cognitive health?
Green spaces reduce stress, improve focus, and provide mental stimulation, which collectively contribute to enhanced cognitive function and slower cognitive decline. - Can green spaces benefit individuals with Alzheimer’s genetic risk?
Yes, the study found that individuals carrying the Alzheimer’s-related APOE-ɛ4 gene experienced a slower rate of cognitive decline if they had regular exposure to green environments. - Does living in a green environment benefit people of all ages?
Although this study focused on midlife exposure, research indicates that green spaces have cognitive benefits for all age groups, promoting brain health across the lifespan. - Why are green spaces particularly beneficial for those from low socioeconomic backgrounds?
Green spaces can help offset health disparities related to stress, access to healthcare, and lifestyle factors, providing a mental health boost for those with fewer resources. - What are some other health benefits of spending time in green spaces?
In addition to cognitive benefits, green spaces can reduce the risk of mental health issues, enhance physical fitness, improve sleep, and contribute to cardiovascular health.
