Forest bathing may boost physical health, not just mental well-being

So-called “forest bathing” is known to have psychological benefits, including reducing stress and anxiety, but now research suggests it also boosts physical health by lowering blood pressure and inflammation.

Also known as shinrin yoku, the Japanese practice of forest bathing involves spending time in nature, usually while taking deep breaths and being mindful of the sights, sounds and smells around you.

Iwao Uehara at Tokyo University of Agriculture and his colleagues wanted to better understand the benefits of this practice, so they looked at 36 adults, aged between 60 and 80, with high blood pressure.

Twenty-four of the adults spent three days and two nights in a forest setting in Qianjiangyuan National Park, about 3.5 hours by car from Hangzhou City in China, where they participated in 3 hours of gentle hiking every day and a 1-hour group mindfulness meditation session on one of the days.

They also took part in one hour of Qigong – a traditional Chinese exercise that uses slow and precise body movements with controlled breathing – every day, along with a 1-hour tea ceremony. These were done to help the participants become more mindful so they could be more immersed in the forest bathing.

The researchers also had 12 people stay in the city and do a similar amount of walking along the streets near their hotel, along with a group mindfulness meditation on one of the days.

Both groups followed the same activity and sleep schedules and ate the same diets. They were also barred from using electrical devices, smoking and consuming alcohol or caffeine during the study.

The researchers measured the participants’ heart rates, blood pressure and levels of C-reactive protein, a marker of inflammation, before and after the intervention.

They found that those in the forest bathing group had significantly improved blood pressure and C-reactive protein levels compared with the city group. They also had higher heart rate variability, a measure of the variation in time between each heartbeat, with higher scores being linked to greater heart health.

“Forest therapy is an inexpensive and reasonable therapy for those with high blood pressure,” says Uehara. The researchers believe forest bathing may calm the nervous system, helping to regulate heart and circulatory health.

The forest group also reported greater reductions in anxiety and stress, and improved energy levels, compared with the city group.

But Julia Gohlke at Virginia Tech says the study didn’t measure how many steps the two groups took. If the forest bathing group took more, that could explain the improved outcomes.

Still, the study backs up previous evidence showing the “decreased stress-related physiological and emotional responses from being in a forest setting,” says Gohlke.