A new study has found that walking in nature may reduce the need for medication for anxiety, asthma, depression, and high blood pressure.

Anyone who spends some time in nature recognizes its benefits. Even a short walk in your local park can lift your spirits. A paper published on 16 January 2023 in the journal Occupational & Environmental Medicine gives some quantitative data to back up this impression.

Researchers from the Finnish Institute for Health and Welfare interviewed approximately 6,000 people in three of the largest cities in Finland about their use of green and blue spaces within a kilometer of their homes.

More specifically, they were asked how often they spent time or exercised outdoors in green spaces during the warm season (May–September). They were also asked whether they had a view of a green or blue space from any of the windows of their dwelling.

In the study, green areas were defined as forests, parks, fields, meadows, boglands and rocks (and any playgrounds and play fields in them), and blue areas as sea, lakes and rivers.

At the same time, the people were asked to submit their use of various medications, including asthma medication, blood pressure pills, and antidepressants.

The study found that visiting nature three to four times a week was associated with:

• 36% lower odds of using blood pressure pills
• 33% lower odds of using mental health medications
• 26% lower odds of using asthma medications.

These associations were not considered to be dependent on socioeconomic status. Interestingly, merely being able to see a green or blue space from home was not associated with possible reduced use of these medications.

These results clearly indicate the health benefits of taking a walk around your local park, forest or lake. Hopefully the results will be noticed by city authorities and developers, who must provide suitable green areas within walking distance of big residential areas.

Why is nature beneficial?

The researchers did not propose any mechanisms for why walking in nature could reduce the use of medication, but possible reasons can be found elsewhere:

Asthma

I would never suggest to someone experiencing an asthma attack that they just need some fresh air. However, getting outside does put us in fresh air where asthma triggers are hopefully not present. Or at least the common triggers such as dust mites, animal dander, scented candles, strong perfumes, dry air, fireplace smoke, etc. I say “hopefully” because going outside can expose a vulnerable person to outdoor triggers like pollen, exhaust fumes and air pollution.

Blood pressure

Numerous studies have found that spending time in forests or around trees in parkland reduces stress, lowers blood pressure and improves mood. Studies examining the same activities in urban, unplanted areas showed no reduction of stress-related effects. Moreover, researchers from the University of Southampton in the UK found that sunlight lowers blood pressure. They found that nitric oxide stored in the top layers of the skin reacts to sunlight and causes blood vessels to widen as the oxide moves into the bloodstream. That, in turn, lowers blood pressure.

Meanwhile, over in Japan, researchers from the Center for Environment, Health and Field Sciences at Chiba University looked at 280 volunteers spending 30 minutes a day visiting a local forest, compared with the same number of people spending the same time in an urban environment. The forest walkers showed significantly lower levels of blood pressure, as well as of heart rate variability.

Mental health

Spending time in nature has been found to help with mental health problems such as anxiety and mild to moderate depression. Being outside in natural light can be helpful if you experience seasonal affective disorder (SAD), a type of depression that affects people during particular seasons or times of year.

Recent research conducted at the Mental Health Foundation in the UK found that spending time outdoors was a key factor that helped people cope with the stress of the COVID-19 pandemic. Throughout the pandemic, 45% of people in a questionnaire said that visiting green spaces helped them to cope with anxiety and depression.

The American Psychological Association has an in-depth and interesting article on how psychological research is advancing our understanding of how time in nature can improve our mental health and sharpen our cognition.

Main photo: Tervuren Arboretum, Belgium by author

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I will be revisiting this subject in later posts when I look at the benefits of forest bathing, the beneficial emissions from trees, nature spirituality practices such as meditation, and other related topics. In the meantime, what are your experiences? Have you found the same – or other – beneficial effects of nature upon your own health? You can comment below: