Forest Walks Boost Immune System

So this scientist in Japan just proved

the air inside a forest can strengthen your immune system.

His name is Ching Li, an immunologist

at Nippon Medical School in Tokyo.

In his first experiment, he took 12

men on a three-day forest trip.

Slow walks, nothing strenuous,

no breathing exercises, and no set route.

Then he tested their blood and he found

a surge in their natural killer cells,

the immune cells your body uses to fight cancer and virus-infected cells.

But what's interesting is that the effect

didn't fade when they went home.

It was still measurable in their blood 30 days later.

The experiment also had a control group

that walked the same amount through the city

and showed no change at all,

further showing that the forest was actually doing the work.

Li found that the airborne compounds that

pine, cedar, and cypress trees release to protect themselves

from insects and bacteria do something to our bodies.

You breathe in these compounds called phytoncides

and they switch your immune cells into higher gear.

And because that immune boost lingered for 30 days,

Li estimates that a forest walk just once a month may be enough

to keep your natural killer cells elevated all year.

It's unfortunate that most of us now spend

over 90% of our lives indoors, but you don't need a prescription for this one.

You just need to go for a walk amongst the trees.