My children and I spent some time in the forests of the Tadoba Andhari Tiger Reserve in Maharashtra recently. The property we stayed in was located in a private forest and we woke up to the sound of birds chirping and leaves rustling as a family of langurs jumped from tree to tree nearby. Yes we saw several tigers, wild buffaloes, chital and sambar too. But what we got from the forest was far more valuable. We felt peaceful and grounded and slept and ate fitfully. The experience rejuvenated us in an intangible but perceptible way. We realized that being in the forest isn’t just about how many tigers you spot or animals you see, breathing in that freshly oxygenated air has to be good for your health too.

The Japanese have a term for spending time in the forest; they call it shinrin-yoku, or forest bathing. Research shows that forest bathing has real, quantifiable health benefits. The Forest Agency of Japan recommended it for health, and we should sit up and take note of it here in India too. Plants and trees release certain protective chemicals in the air that surrounds them. These airborne chemicals, called phytoncides, have antibacterial and anti-fungal properties. Phytoncides bolster plant immunity—and it turns out that they strengthen our immunity too.

Qing Li from the Nippon Medical School in Tokyo, found just how forest bathing and exposure to phytoncides boosts our immune system. Li studied the effect of a three-day, two-night trip into the forest on 23 Japanese men and women. He took blood and urine samples during a regular workday before the study participants went to the forest. He also took a few samples while the participants were on the trip, and, then, a week and a month later. He found that spending time in the forest and breathing in phytoncides increased the number and activity of a type of white blood cells called natural killer cells, or NK cells. These cells serve to kill tumour-and virus-infected cells in our bodies.

Forest bathing also increased levels of intracellular granulysin, perforin, and granzymes that improve our body’s ability to fight bacterial and parasitic infection. And the improved immunity didn’t last only as long as these participants were in the forest; it lasted for at least a month after their visit. In contrast, a visit as a tourist to a city did not show the same immune-protective effects. The study results were published in the journal of Environmental Health And Preventive Medicine in January 2010.

Spending time around trees, even just looking at them, can reduce stress, lower blood pressure and improve our mood. Numerous studies show that exercising in forests, or simply sitting and looking at trees, reduces blood pressure as well as the stress-related hormones cortisol and adrenalin. Since stress inhibits the immune system, the immune-enhancing effects of being in the forest, surrounded by green, are further magnified.

I would recommend the real thing whenever possible, though even looking at pictures of trees has a similar, but less dramatic, effect. And of course having some green plants to look at in your office is a good idea if stepping out into the green isn’t possible. For workplace wellness, it would make sense for offices to place plants around the office. By the way, studies that looked at walking, or simply sitting and staring, in urban, unplanted areas showed no reduction of stress-related hormones and blood pressure.

We’ll be making a weekend trip to a forest close by every few months from now on. The advantage with a belated New Year’s health resolution like this one is that it’s a fun one to keep. As naturalist and author John Muir said, “And into the forest I go, to lose my mind and find my soul".

Sujata Kelkar Shetty, PhD, is a wellness expert and a certified life coach. She has worked as a clinical scientist at the National Institutes of Health in Bethesda, US.