It’s one of those picture-perfect days and I’m on a shuttle bus with a group of parents and kids heading to Lake Chabot Regional Park in Oakland. Getting here on a Saturday morning included rushing through breakfast, dressing squirming kids, squeezing in errands, driving to the wrong location—argh!—and finally arriving at an outpatient clinic of the UCSF Benioff Children’s Hospital in Oakland. A dozen other parents were there, settling their kids. I wondered about their harried mornings and checked my phone—a text from my husband said the kids were happily making a mess of the kitchen. Then Dr. Nooshin Razani, a big-hearted pediatrician on a mission, called the group together and, before we boarded the shuttle, asked us to rate our stress level on a scale of 0-5. Okay, mine: 3 or 4 (could be worse, I thought). “Take a deep breath,” she urged. “I give you permission to not answer your phone for three free hours.”
Soon we exit the highway into the rolling, golden hills leading to Lake Chabot Regional Park and a 5-year-old boy announces, “I’ve been to a lake before!” Razani’s goal is for her patients to make time in nature a regular part of their lives. The vast majority of them live below the poverty line and Razani, herself a busy mother of three as well as a clinical researcher, strongly believes spending an afternoon at the lake is worth their time and effort. And so, in partnership with the East Bay Regional Park District and the Regional Parks Foundation, she’s spearheading these monthly outings, known as the SHINE (Stay Healthy in Nature Everyday) initiative, to make visiting parks easier for the socioeconomically disadvantaged families who use her outpatient clinic.
“A lot of people have the idea that it’s a luxury, and [that] it’s almost patronizing to people who have more basic needs if we start talking about nature,” Razani told me. “No one is saying, ‘Go to a park and you won’t need to feed your children anymore.’ But there’s an unbelievable amount of stress on families, and there’s one source of help that’s pretty effective and available in the community.”
Soon we’ve disembarked and Razani waves us over to a stand of redwoods. “Everybody, come to the trees,” she projects in an authoritative doctor voice. “These trees are doing their work right now. Within five minutes in the trees, our heart rate goes down and within 10 minutes our brain re-sets our attention span.” The day in nature begins with a free lunch, and then the group, led by a park district naturalist, heads to the lake, pausing on a boardwalk to pick blackberries before striking out along a trail.
Nature is restorative; that’s practically a truism to anyone who loves the outdoors. The effects start within minutes and can be long-lasting, even transformative, when nature works on us over the course of days or weeks. Scientific research now confirms what we already know: We become more relaxed, more open and friendly, and more creative, with better memory and concentration, after being in nature. Nature lowers blood pressure, reduces stress, and bolsters our immune system. In fact, the benefits from contact with nature are now so well documented that they’re showing up on the health care industry’s agenda, and protecting nature can be seen as a public health strategy.
The American Public Health Association now urges health practitioners to advise patients to spend more time in nature for exercise and play, and has called for more green space in school yards, medical facilities, and in urban design. Meanwhile, an international movement called “Healthy Parks, Healthy People” has taken root in more than 30 countries. The Bay Area chapter—a partnership between the National Park Service, EBRPD, and the Institute at the Golden Gate—is focused on getting people at high risk for chronic disease into parks, and offering them free tai chi and yoga classes, guided walks for families, and other activities there. Razani and doctors around the country are writing their patients “parks prescriptions” along with, or even instead of, drug prescriptions, elevating time outdoors to a medical necessity. In Razani’s practice, the SHINE initiative helps ensure that patients get their medicine.
But what is it, exactly, about nature that heals us? As the healthcare industry tries to put theory into practice, scientists seek a fundamental understanding of the mind-body mechanisms at work during our time outside. I’ve been contemplating this question, and as I walk along with the SHINE group at Lake Chabot, I feel the surroundings begin to seep into me—the touch of the wind on my skin, the crunch of a rock underfoot, the perfume of the California bay laurels, all bring back memories of backpacking in Northern California with my husband long before the kids came along. I glimpse the lake, expansive and shimmering, through openings in the trees, and all my senses attune to the stillness of this place. It’s in this sort of simple experience that scientists have started to find answers.
In 1984, biologist Edward O. Wilson popularized the term “biophilia,” Greek for “love of life,” in his book of the same name. Wilson writes that “to explore and affiliate with life is a deep and complicated process in mental development … our existence depends on this propensity, our spirit is woven from it, hope rises out of its currents.” He posits that the human mind, while shaped by the modern world, is deeply rooted in the natural conditions that our species evolved in. And so, for example, we are evolutionarily drawn to bodies of water and living landscapes because they signal to us the nourishment and shelter that sustained us for millennia.
Some of the early scientific research backing up Wilson’s ideas came from a husband-wife team of psychologists at the University of Michigan, Rachel and Stephen Kaplan. In the 1980s they began testing their theory that “restorative environments,” particularly in nature, could renew one’s capacity to pay attention. Based on preliminary research that a wilderness camp experience was psychologically transformative for youth, the Kaplans proposed that our brains fatigue when our attention—a mental muscle, of sorts—is overtaxed, leading to impulsive and irritable behavior. The antidote: Spend time in a place where attention is less directed and stimuli are “softly fascinating,” allowing our brains to rest, wander, and feel transported.
While there are clearly other ways to achieve such moments—a Beethoven symphony, standing in St. Peter’s Basilica, or meditating in a dimly lit room, to name a few —nature is (ideally) accessible in the small moments of the everyday. In one well-known study, Rachel Kaplan found that office workers with a window view of natural scenery felt less frustrated, more patient, more enthusiastic about their jobs, and reported higher life satisfaction, as well as better overall health, than those without a view of nature. “Thus, a view from the window might be called a micro-restorative experience,” Kaplan writes. “One that provides a brief respite to one’s directed attention. Even in a moment’s glance one might feel that one is far away; the snow on the tree, the changing colors of the leaves, the bird barely visible in the bush all draw one’s attention effortlessly and provide the sense that one is somewhere else. Even such a brief opportunity to recover one’s attentional capacity might be expected to enhance competence and cooperativeness.”
Kaplan’s ideas have been borne out in cognitive studies. Memory researchers have found that people who walked through an arboretum scored better when asked to repeat a set of numbers backwards than those who walked an urban route. And in a recently published study of 94 high school students in Illinois, those in classrooms with windows overlooking greenery scored significantly higher on attention tests and physiological stress recovery measurements than those with no window or with a window that looked out onto a barren landscape. “The body of work is pretty convincing that something differs in how the environment impacts our cognition and our [feelings],” says Gregory Bratman, a biopsychologist at Stanford University.
Looking to answer “how,” Bratman and other scientists have homed in on the prefrontal cortex—the brain’s command and control center, responsible for a vast array of higher-level thinking, and the area where short-term memory resides, along with our ability to pay attention. It turns out that modern life, with its constant sudden events—alarms, pings, cars bearing down on you at crosswalks—and almost nonstop multitasking, is pretty hard on the PFC. And, unfortunately in this context, the PFC’s built-in novelty bias draws our attention to the million little distractions that, say, smartphones offer, at the expense of sustained, focused effort. This constant mental multitasking ramps up the production of the stress hormone cortisol, as well as the fight-or-flight hormone adrenaline.
While the Kaplans and other researchers have studied attention fatigue and recovery, Bratman is focused on the phenomenon of rumination, a particularly maladaptive pattern of thinking that can lead to depression and other mental disorders. Rumination entails dwelling on the causes and conditions of one’s distress without looking for solutions. Everyone ruminates to some extent, some people more than others. It’s well understood that the PFC is also active during rumination, in particular the subgenual area, a region that displays increased activity during periods of sadness and can run amok by turning the normal process of self-reflection into a depressive state. And so Bratman and his team decided to put the brains (and the bodies, of course) of 38 healthy, urban adults to a test. He randomly split the group in two and each spent 90 minutes walking in two drastically different settings. One group walked alongside a steady stream of traffic on El Camino Real; the other walked the grassy slopes of The Dish in the foothills above Stanford’s campus. Before and after the walks, Bratman and crew measured blood flow to the subgenual prefrontal cortex using an fMRI brain imaging device as well as gathered self-reports on rumination with a questionnaire. “I wanted to see if environmental differences play a role in increasing and decreasing this type of thought pattern,” he says.
Sure enough, the team found that a walk around The Dish correlated with a statistically significant decrease in blood flow to the subgenual area, indicating less brain activity there; participants also reported less rumination. Those who walked along busy El Camino had little to no change. The results led Bratman to conclude that a nature experience can impact this neural pathway in the brain, and that access to preserved open spaces like The Dish may be a critical resource for improving the “mental capital” of urban areas.
“By no means do I say that nature cures depression,” Bratman says. “But as we continue to urbanize, the question becomes more and more relevant to more and more people: What are the repercussions if we don’t bring nature into the city or conserve it outside of it?” Working alongside conservation biologist Gretchen Daily, a pioneer in the field of “ecosystem services,” Bratman is hoping to further the case that nature is valuable for its psychological benefits and can serve to augment other mental health treatments. In further research, he’s trying to isolate some of the “active ingredients” in natural environments that impact our psychology, using a controlled laboratory setting to pit birdsongs against car horns and vehicle exhaust against the smell of trees.
Not only can the outdoors bring people together, but the aesthetics of nature, in contrast to urban landscapes dominated by hard, flat surfaces, can likewise change our outlook.
Razani also worries about our alienation from the natural world. She says children in Western cultures spend half as much time outside as their parents did when they were young, and the typical American adult spends 90 percent of his or her life inside buildings. In urban living “there’s a lot of feeling of isolation and a lack of belonging,” she adds. Not only can the outdoors bring people together, but the aesthetics of nature, in contrast to urban landscapes dominated by hard, flat surfaces, can likewise change our outlook.
Scientists have been studying a universal aspect of nature that seems to please us to no end—fractals. These self-repeating patterns, found in everything from the spiral of a snail’s shell to the branching of trees, provide both order and a high level of complexity to nature. A fractal is a shape in which, when you look at a small part of it, the small piece has a similar—but not necessarily identical—appearance to the full shape. A tree, for example, may have a large trunk, then a couple of main branches, then more branches of the next size, and many, many more twigs. “There’s some regular, repeating amount of detail regardless of how close we look at something. We have evolved to make sense of that,” says Jonathan Wolfe, a visual neuroscientist and founder of the Fractal Foundation, an organization seeking to increase curiosity about natural systems and mathematics.
There’s also a roughness, or imprecision, in the way fractals appear in nature (as opposed to a fractal created with a ruler or on a computer). It’s this roughness, present at all scales, on a natural object that may hold our fascination. Participants in another recently published study were asked to contrast pictures of tree branches and grass fields to pictures of a modern building, each at various levels of magnification. The researchers found that people perceived the magnified natural images as more visually complex and they freely viewed them longer than they did the building photos magnified at different scales.
The researchers concluded that the higher degree of fractal complexity in the natural images held people’s interest longer.
Other studies of our response to fractals look at brain waves. Electroencephalograms (EEGs) record different types of synchronized electrical pulses as the masses of neurons communicate with each other. Brain waves are like the “musical notes” of the mind (they are even measured in hertz) that change according to what we’re doing and feeling. Delta waves are slow and loud, like a drumbeat, and are generated in dreamless sleep, while the higher-frequency beta waves dominate our waking consciousness when we are engaged in external cognitive tasks. In between are alpha waves, present during quietly flowing thoughts, deep relaxation, and some meditative states.
Several studies out of Sweden using EEGs have found that alpha waves tended to surge when people viewed imprecise (rough) fractals and were less present when they viewed artificial (exact) fractals, indicating that the fractals found in nature are especially soothing. The studies have also determined that fractals with mid-range complexity, which happen to be common in nature, bring about high alpha and beta waves, pointing to a complex interplay between different parts of the brain. The alpha waves suggest a restorative and relaxed state and the beta waves a processing of the fractal’s spatial properties. The researchers explain that “what makes nature so suitable for attention restoration is the mix of variation and predictability in its visual patterns.” An artificial fractal might be too predicable, while a natural fractal pattern might have “a more optimal mix of order and variation that is effortless to attend to but is still interesting enough to hold the attention.”
Caroline Hägerhäll, the Swedish researcher who conducted the EEG studies, says that the human eye easily scans mid-range fractals. “The ease of processing and the aesthetic appeal of [mid-range] visual fractals might be due to this resonance with the eyes’ physiological behavior,” she says.
We eventually reach a bend in the path that crosses a dry streambed. The children climb across the thick trunk of a fallen tree. There’s a lot of laughing and posing for pictures. A culvert under the path becomes a tunnel to explore with Razani in the lead. It’s a joyful and social moment. “It just feels so good to be outside,” says Ramses, an eighth-grader who recounts long hours in school and with homework. “Yes, there’s bees and other animals, but I like seeing all kinds of things—like the redwoods are tall and mysterious.”
Feelings evoked outdoors represent another area of study that examines how time spent in nature can lead to healing. One such feeling is awe—that intense and otherworldly feeling that comes when we’re faced with something so vast that it transcends our preconceived notions of the world. Craig Anderson, an emotions researcher at UC Berkeley in the field of positive psychology, is an expert in reading faces and body language. His research leads him to conclude that while cathedrals, charismatic people, and great music can all inspire awe, nature doles out the most reliable moments of it, from summiting a mountain to observing the papery wing of a butterfly. “Colloquially, it’s something that blows your mind,” says Anderson, a New Mexico native who loves staring at the big night sky.
For the last three years he’s sent raft-loads of Oakland teens from underserved communities, as well as military veterans suffering from post-traumatic stress disorder (PTSD), down the South Fork of the American River on the theory that being battered about by the force of a raging river might cause a shift in their lives. He’s trying to understand that change by recording the rafting experience with a GoPro suction-cupped to the front of the boat and pointed at the faces of the paddlers. The boat bobs up and down, and they scream as the rapids crest over the raft. He watches the rafting footage in 10- to 20-second frames to code the emotions.
The whitewater study is ongoing, but the data is already revealing some interesting findings. Anderson says the trips are having lasting effects on the emotional states of the participants, with veterans having a 30 percent drop in PTSD symptoms a week later. He’s also finding that the hormones in raft-mates change by similar amounts, so much so that Anderson says he can predict which people rafted together just by looking at their before-and-after hormone levels. “So, whether it’s through emotional expression or physical touch or teamwork, somehow they’re syncing up physically as well. I think the social component of it is going to be a big part of the story.”
The Sierra Club is supplying the military veterans and much of the funding for the whitewater rafting study. Club Outdoors Director Stacy Bare, himself a military veteran, suffered from PTSD and suicidal thoughts when he returned from active duty. He dreams of a future when kayaks and hiking boots are covered by medical insurance like any other durable medical device, and when going outside into nature is given the same legitimacy in promoting health as a doctor visit.
“I’m not saying we’re going to do away with pharmaceuticals,” he says. “But over time we can reduce costs significantly and create a healthier, more empathetic, pro-social country through time outside.” In the meantime, he adds, the nature research needs to be further nailed down with larger and longer-term clinical studies that have all the components of scientific objectivity. “We have to figure out how to do a double-blind randomized controlled trial.”
“We thought no one would listen to us. They don’t listen to us on lifesaving medication, so why would they go to parks just because I told them to?”
With support from the EBRPD, Razani has conducted her own research to demonstrate how time outdoors works in the messy context of her patients’ lives. “All this research has been done on nature and health and there’s this real movement in health care, but no one had done the bench-to-bedside work,” she says. In 2015, she enrolled 78 parent-child pairs to spend time in nature three times a week for three weeks. She then randomly divided the group in two, offering one group an additional organized weekly SHINE outing while the other group visited parks independently. At the beginning of the study, a week after its conclusion, and then two months after that, Razani collected information on a range of well-being indicators: questionnaires, saliva swabbing for a common stress enzyme, physical activity with a pedometer, and adherence to the program.
The results: Stress levels dropped for the majority of participants in both groups, according to cortisol levels and a validated questionnaire. Two months after the study ended all participants reported they were still visiting parks, and the independent group averaged four visits a week, even more than they agreed to during the study. The patients with access to the SHINE group, however, uniquely had significant declines in loneliness.
Razani was surprised by her findings. “We thought no one would listen to us. They don’t listen to us on lifesaving medication, so why would they go to parks just because I told them to?” she says. “I learned that it’s a very valuable conversation and empowering. The next step is to do it bigger.”
Back on the trail, we’ve turned around at the streambed and we start heading home, a canopy of tree branches overhead. The kids have a list of items to spot and are busy making a game out of looking for spiderwebs and clouds and other common treasures in nature. Razani chats with me about a deeper aim in her work: to not only help her patients feel better as they connect more with nature, but eventually act to protect it. Healing humans and healing the environment go hand in hand.
Find out more about the Healthy Parks, Healthy People initiative on their web site.