Nature’s Powerful Mood Medicine

Did You Know…nature offers more powerful mood medicine than many prescription drugs?

A recent study led by researchers at Stanford University found that walking in nature could measurably improve your mood, without risks or side effects.  The findings, published in the Proceedings of the National Academy of Science, indicated that walking alone would not suffice.  To experience the maximum health improvements, it’s essential to walk in a natural setting.

Participants who walked for 90 minutes in a natural area experienced decreased activity in an area of the brain linked to depression.  Participants who walked for the same length of time in an urban setting, however, did not experience the same shift in neural activity.

More City Dwellers, More Problems 

The implications of the Stanford study are especially relevant to city dwellers—who make up more than half of the world’s population.  And over the next few decades, projections show that number rising to 70%.  As more and more people move into cities and away from nature, rates of mental disorders—including depression—continue to spike.


Risks of City Dwelling

If you live in a city, you have a 20% higher risk of developing an anxiety disorder and a 40% higher risk of developing a mood disorder than if you live in a rural area.  Individuals born and raised in urban environments have twice the risk of developing schizophrenia!

Into the Woods 

For the Stanford study, 2 groups of participants each took 90-minute walks.  One group walked in a grassland area populated by oak trees and shrubbery, the other walked along a highly trafficked four-lane road.  To assess results, researchers considered:

  • Heart and respiration rates
  • Brain scans
  • Participant self-surveys before and after the walks

     Physiological conditions—heart and respiration rate, for instance—remained fairly consistent between the groups, but when it came to neural activity patterns in the brain, the nature walkers differed dramatically from the city walkers.

Participants who walked in nature showed a marked decrease in activity in the subgenual prefrontal cortex, an area of the brain that lights up when people dwell on negative emotions.

How Nature Makes Us Feel Better 

According to Gregory Bratman, lead author and graduate student in Stanford’s Emmett Interdisciplinary Program in Environment and Resources at the Stanford Psychophysiology Lab and the Center for Conservation Biology, the study demonstrates the impact of nature on emotion regulation.  Bratman believes it may help to explain how nature makes us feel better.

Some attribute the effects to naturally generated molecules called negative ions.  All natural environments are rich in negative ions, which energize the body on a cellular level.  Negative ions boost the flow of oxygen to your brain, which increases alertness and decreases lethargy.

When our stores of negative ions become depleted, we experience symptoms such as…

  • Fatigue
  • Poor sleep
  • Loss of bone strength
  • Overactive adrenal glands
  • Chronic inflammation
  • Anxiety
  • Depression
Prioritizing Natural Vitality

Co-author Gretchen Daily, the Bing Professor in Environmental Science and a senior fellow at the Stanford Woods Institute for the Environment, said the results of their study suggest “accessible natural areas may be vital for mental health in our rapidly urbanizing world.”
Daily hopes their findings will be used to make cities more livable, and nature more accessible.  For now, it seems any extra leg work that may be involved in making time for a nature walk will be well worth it!