Trees help your body heal. They boost your immune system, help you recover faster, and you’ll need fewer pain relievers.

Research has shown spending time in a forested environment helps your body’s immune system by increasing the number and activity of disease-fighting cells. The numbers of NK (“Natural Killer” cells of the immune system) and substances released by them are significantly higher on days people are immersed in trees. NK cells have been reported to kill tumors and other virus-infected cells. In fact, the increased NK activity lasts for more than 30 days, suggesting a visit to a forest once a month will enable individuals to maintain a higher level of NK activity.

Even a view of trees out your window can help with healing. Hospital patients with a view of trees while recovering from surgery have shorter recovery times and require fewer pain relievers than patients with a view of a brick wall. Patients also have fewer negative comments for nurses and fewer post-surgical complications. A study of two hundred people demonstrates the positive effects outdoor visual environments can have on healing.

Trees are also good for babies. Multiple studies have shown a positive correlation between increased birthweights and an increase of greenery in mothers’ living environment.

These findings further support the concept of urban forestry closely relating to public health. Taking a more purposeful approach to the design and maintenance of our community’s green spaces will benefit us all. Not an apple, but a tree a day, will keep the doctor away.

For more information and links to published research, visit the Vibrant Cities Lab, Association between residential greenness and birth weight: Systematic review and meta-analysis and Effect of forest bathing trips on human immune function. Use this interactive map to find Wisconsin Parks and Trails near you.

Article written by: Olivia Witthun, WI DNR Urban Forestry Coordinator, 414-750-8744, Olivia.Witthun@wisconsin.gov