Nature is Medicine: How Forest Bathing (Shinrin-yoku) is Redefining the Way We Think About Health

Grounded in both ancient wisdom and clinical research, physicians and wellness leaders are turning to nature for answers in an increasingly anxious world.

STATE COLLEGE, Pa., June 3, 2025  – Imagine yourself stepping into a forest where time slows down. Light filters softly through the canopy, a chorus of birdsong echoes in the distance, and the earthy scent of pine and moss rises with each step. What do you notice first? The crunch of leaves underfoot, the warmth pressing gently on your shoulders, or the stillness in your mind? As you wander deeper, ask yourself: How do you feel here, unplugged and surrounded by green? Peaceful? Restless? Recharged? Or are you secretly counting how many bars of service you’ve lost?

The rise in smartphones, social media and other modern technology—coupled with a growing movement away from rural areas—has weakened Americans’ connection to the natural world. Access to nature is a privilege, one that many of us don’t recognize. Yet a relationship with the outdoors is essential to our quality of life, health, social well-being, prosperity and productivity.

Growing evidence suggests that technology use contributes to rising rates of stress, anxiety and other health issues. But stepping into the forest can help counteract those effects. The ancient practice of Shinrin-yoku, or forest bathing, is a Japanese practice that involves immersing oneself in a forest or natural environment to consciously engage with our senses and surroundings. In Japan, forest bathing is viewed as both an art and a form of meditation, with roots in local traditions.

Dr. Michele Antonelli, a physician specializing in preventive medicine with expertise in evidence-based complementary therapies, nutrition, clinical prevention and environmental health, has worked in this field for over 20 years. He currently works in private practice.

One study by Antonelli, published in the National Library of Medicine, aims to investigate the effects of forest bathing on levels of salivary or serum cortisol as a stress biomarker to understand whether forest bathing can reduce stress.

“Even just looking at the forest, even just contemplating the forest from far away can reduce cortisol levels and stress hormone levels in short term,” said Antonelli. “At the same time, when we talk about anxiety, respiratory function and other parameters, the most fundamental component is the inhalation of volatile organic compounds, mostly terpenes, such as pinene or limonene.”

Spending 15 to 20 minutes in nature can produce effects that last a few hours. Two to four hours can result in benefits lasting several days. And if you spend a few days immersed in nature, the effects can persist for weeks. That’s why Antonelli recommends visiting natural environments at least once or twice a month to prevent stress-related diseases.

These beneficial substances enter the body through the airways and reach the bloodstream and brain. Terpenes are aromatic compounds responsible for the scent of many plants and herbs, including rosemary, lavender, mushrooms and pine. They help plants survive by deterring grazers or pests and by enabling plant-to-plant communication.

Antonelli explained that people exposed to high levels of terpenes experience greater reductions in anxiety and stress, as well as improved respiratory function, compared to those exposed to lower levels. When other variables are accounted for, this becomes a critical factor in the effectiveness of forest bathing.

However, not all forests are created equal—and not all plants emit the same levels of terpenes.

Antonelli and his team conducted research in the Alps, near Misurina, Italy, focusing on adolescents with asthma. “The effects of forest bathing are more pronounced around water basins like rivers, lakes and alpine streams of quickly flowing water,” he said. "The humidity in the atmosphere maximizes your exposure to terpenes.”

Terpenes in pristine environments like these tend to have stronger effects because the air is less polluted. The challenge, Antonelli explained, is finding study sites that are both accessible and far from pollutants. This matters because atmospheric pollutants can bond with terpenes and other natural compounds, creating negative reactions. 

Since not everyone can access pristine forests, especially in the U.S., we must find creative ways to foster connections to nature. That’s where ClearWater’s Centred Outdoors program comes in. ClearWater Conservancy is working to nurture a healthy environment and thriving communities in the heart of Pennsylvania. Centred Outdoors focuses on connecting people to place and one another by discovering natural landscapes in the region. The Centred Outdoors wellness programs and guided outings help engage all who want to experience the awe of the outdoors and connect to nature. Through this program, participants are invited to further collaborate in effective and lasting conservation with ClearWater Conservancy.

During a forest therapy walk, the trained guide uses a clearly defined sequence of events and invitations in partnership with the forest which allows participants to slow down, allow the senses to open, and experience the environment using all senses. This supports the wholeness and well-being of both.

While anticipated placebo effects do play a role, Antonelli emphasized the importance of placebo effect in medicine, specifically in ritual. “We all kind of work the same way, more or less, with some cultural differences,” he said. “We have to go to the shaman, and the shaman has to give us some potion—the receipt of a cure.”

In Italy, forest bathing is more popular among women in their 40s to 60s, who tend to have higher-than-average anxiety levels. Men, by contrast, often participate as part of broader efforts to improve their health through physical activity. Regardless of gender, participants often already have high levels of environmental awareness.

Because of this, Antonelli cautioned against viewing forest bathing as a tool for raising environmental awareness because it tends to attract those who already care deeply about nature. 

Still, in an area like Centre County, where diversity of background and perspective is so pronounced, practices like forest bathing can nurture a deeper commitment to conservation. This is especially true for participants who are new to the area, and might not have had prior access to the outdoors. The key here also, is in peer storytelling. During an invitation called “power of presence,” participants are asked to find an item in nature that speaks to them, share their thoughts in a safe environment, and listen to others.

Mary Price is our Certified Forest Therapy Guide through the Association of Nature and Forest Therapy Guides and Programs. She is also certified in Wilderness First Aid through Wild Med, and is certified in CPR/AED for adults, children, and infants through the American Red Cross. She has earned a Mental Health First Aid certification through Penn State Extension and has practiced Mindfulness Meditation for over ten years.

"The forest is the therapist. The guide simply opens the door," said Price.

As interest in Shinrin-yoku grows beyond its Japanese roots, it offers a fresh lens through which we can reimagine our relationship with the natural world, especially in an age where disconnection is the norm. Whether it’s a guided practice in Big Flat Laurel Natural Area or a quiet solo walk in Lederer Park, the invitation remains the same: to slow down, pay attention, and allow the forest to meet us where we are.

As Suzanne Bartlett Hackenmiller, MD, writes in The Outdoor Adventurer’s Guide to Forest Bathing, “One thing that sets forest bathing apart from mindfulness, in its truest sense of the word, is that in mindfulness practices, the object is to remove oneself from emotion and reaction to one's surroundings. In forest bathing, however, there is a celebration of the experience of awe and wonder during the time spent in nature.”

And perhaps in that celebration, we find a path back to ourselves.