The Positive Impact of Green Spaces

In 2012, a group of hikers embarked on a multi-day adventure into the wilderness, free from electronic distractions. Prior to their journey, they took a creativity and problem-solving test. After four days in nature, their scores increased by 50%, from an average of 4.14 correct answers out of 10 to 6.08.

As with many psychological studies, this one couldn't definitively establish causation. It remains unclear whether the improvement stemmed from nature itself, the break from technology, or the physical activity involved. However, the researchers — Ruth and Paul Atchley from the University of Kansas and David Strayer from the University of Utah — shared their insights:

“Our modern environment is filled with abrupt distractions that capture our attention,” they noted in the journal PLOS ONE. “In contrast, natural settings promote a gentle fascination, allowing our cognitive systems to rejuvenate.”

> “Spending time in, or living near, natural green spaces is linked to various significant health advantages.”

Previous research had already indicated that the benefits of green spaces extend to everyone, not just seasoned outdoor enthusiasts.

In 2006, a study led by behavioral scientist Jolanda Maas revealed a significant correlation between green space within a two-mile radius and perceived health, based on data from over 250,000 individuals in the Netherlands.

Maas and her team followed up in 2009, examining health data for 24 diseases. They found that individuals residing in greener areas exhibited lower rates of 15 conditions, notably anxiety and depression, as reported in the Journal of Epidemiology & Community Health.

Other studies have demonstrated that access to green views can alleviate stress and pain in hospital patients, enhancing their immune responses and recovery rates.

Moreover, a small 2011 study found that gardening was more effective at reducing stress than reading. Participants who engaged in gardening after a stressful task exhibited significantly lower cortisol levels compared to those who read indoors.

In a broad review conducted last year, analyzing data from over 290 million individuals across 20 countries, the significant health benefits of nature were reaffirmed.

“Living near or spending time in green spaces correlates with diverse health benefits,” said lead researcher Caoimhe Twohig-Bennett from the University of East Anglia. “It lowers the risk of type II diabetes, cardiovascular issues, premature death, and preterm birth, while enhancing sleep quality. Proximity to nature is associated with reduced blood pressure, heart rate, and stress levels.”

Nature's Role in Child Development

An important caveat in these studies is that being outdoors often entails being active.

Whether it’s hiking, gardening, or briskly walking in a park, participants are likely engaging in what researchers term “moderate physical activity,” which is known to elevate mood, enhance cognitive function, and improve physical health.

“Individuals living near green areas likely enjoy more opportunities for physical activity and social interaction,” Twohig-Bennett noted, acknowledging the challenge of establishing cause-and-effect relationships.

The scientific community remains divided on whether it's nature itself or the physical activity associated with being outdoors that promotes health benefits. Douglas Becker, a graduate student at the University of Illinois, recently published a study examining the impact of nature on healthcare costs.

Becker analyzed health and environmental data from nearly all U.S. counties, discovering that areas with greater forest and shrubland cover had lower per capita Medicare expenses. His findings suggested that every 1% increase in forested land was associated with a $4.32 reduction in Medicare costs per person annually.

“Scaling that up reveals significant national savings, approximately $6 billion in reduced Medicare spending each year,” Becker remarked.

However, Becker cautioned that his analysis does not definitively prove that increased greenery directly leads to lower healthcare costs. Instead, it provides further evidence supporting the idea that green spaces are beneficial for our health.

“Being in sight of nature does indeed offer advantages,” he concluded.

Twohig-Bennett highlighted another potential aspect, suggesting that exposure to diverse bacteria found in natural environments may enhance immune function and decrease inflammation.

“Research indicates that ‘forest bathing,’ a therapeutic practice in Japan involving immersion in forests, may yield health benefits,” she noted, referencing studies suggesting that phytoncides — natural antibacterial compounds released by trees — could be responsible for the positive effects associated with this practice.

The Impact of Nature on Mental Health

In 2015, Stanford University researchers added to the growing body of evidence that there are distinct benefits to being in nature, separate from the act of walking itself. They compared the effects of hiking in natural areas against urban settings.

While no significant physiological differences were noted post-hike, those who trekked through nature exhibited decreased activity in the subgenual prefrontal cortex, a brain region associated with ruminating on negative emotions.

“This suggests that experiences in nature positively influence emotional regulation, potentially explaining how nature enhances our well-being,” stated lead author Gregory Bratman.

The implications of these findings extend to urbanization and its potential link to rising rates of mental health issues.

Studies have shown that individuals raised in greener environments have a 55% lower risk of mental disorders in adulthood, according to recent research involving nearly one million Danes published in Proceedings of the National Academy of Sciences.

“There’s mounting evidence that the natural environment significantly impacts mental health,” said study leader Kristine Engemann. “Our findings indicate that the longer one is surrounded by green spaces during childhood, the lower the risk of developing mental health issues.”

Educators have recognized the positive influence of nature on children's well-being for years, and as scientific support grows, the prevalence of nature-based preschools and forest kindergartens in the U.S. has surged by over 60% recently.

The Nature Prescription

How much time is needed in nature to reap its benefits? While it’s widely accepted that more time is better, recent research indicates that even short durations can be effective.

A study published in Frontiers in Psychology revealed that spending just 20–30 minutes in a natural setting can significantly lower cortisol levels, the stress hormone.

Researchers had 36 urban participants take breaks for 10 minutes or more, three times a week over eight weeks, in environments that made them feel connected to nature. Importantly, they were instructed to avoid physical exercise, reading, conversations, or phone usage during these breaks.

The most significant reductions in stress were observed among those who spent 20 to 30 minutes in their chosen natural environments.

“Our findings clarify that for optimal stress relief, individuals should dedicate 20 to 30 minutes to sitting or walking in a place that evokes a sense of nature,” stated lead researcher MaryCarol Hunter from the University of Michigan.

Hunter and her team propose that healthcare professionals might consider prescribing a “nature pill” based on these findings.

When combined with regular exercise, quality sleep, and a balanced diet, a nature pill could become a fundamental aspect of science-backed well-being. For my son and me, daily trips to our fishing spot may not be feasible, but there’s a hiking trail nearby that leads into the desert and up a mountain. We’ll be heading out there soon.