Getting Your Steps and "Forest Bathing"

By Benjamin Kligler, MD
We have all heard the words “10,000 steps,” accompanied by the strong statement that this is the amount needed every day to keep us healthy. But as it turns out, that number 10,000 was never really based on any specific science or studies, and researchers have recently discovered that in fact a significantly lower number of steps—around 4400 per day—is the threshold for significant decreases in mortality. This new information comes courtesy of 18,289 women in the Women’s Health Study who agreed to wear a device which measured their number of steps over a period of several years.[i]

For those exercise junkies out there, don’t despair: the benefit of walking increases as the number of steps rises to 7500—meaning that all that effort you have been putting into moving every day hasn’t been for nothing! But beyond 7500 steps per day, the researchers did not find any additional benefit in terms of reduced mortality. And, the speed or intensity of the walking turns out not to matter—just the total number of steps.

So why is this newsworthy? Well, especially for many older people—but also for many with significant obesity, cardiovascular disease, or other chronic illness—10,000 steps per day has always seemed like an unachievable goal. And having an unachievable goal is sometimes worse than having none at all, because it demoralizes people and takes away their motivation to even get started. So, having solid data that a much more achievable level of exercise is actually effective is very important.

And while you are planning how to get your 4400 steps in per day from here on out, you may want to be aware of another important new area of research looking at the health benefits of spending time outdoors in a natural environment doing what is known in Japan as “Shinrin-Yoku,” or “Forest Bathing.”[ii] As it turns out, more frequent exposure to natural environments can lead to all kinds of health benefits, including decreased symptoms of depression and anxiety, lower levels of stress, and improved cognition in children with attention deficit disorder.[iii] And the benefits of green space are not limited to mental health conditions, either: a Dutch study of over 345,000 people found that living in areas with a higher percentage of green space led to improvement in all kinds of physical health measures as well—including cardiovascular disease, chronic back pain, and diabetes among others. And importantly, this was true for people at all levels of socioeconomic status—meaning that improved health when people live near green spaces is not just a function of higher economic status.[iv]

The reasons for this “forest bathing” phenomenon are still being studied, but there are some early clues. For example, forest bathing seems to lower cortisol levels—a marker of chronic inflammation—and also seems to improve the function of a group of immune cells called natural killer cells, which are responsible for fighting off both cancer and infection.[v] The overall decrease in levels of stress may also play an important role, since stress is linked with so many chronic illnesses. And many of these benefits are seen with as little as 15-20 minutes of time outside.

So, get going with your steps (though not as many as you thought you needed!) and find a way to get out in the green while you’re doing it if you can. And maybe even more importantly, make sure your kids get this message early on about how important regular physical activity and outdoor time can be for your physical and mental health.

Dr. Kligler is the Medical Advisor for The Deirdre Imus Environmental Health Center^®. He is also the National Director of the Integrative Health Coordinating Center for the Veterans Health Administration and Research Director for the Office of Patient Centered Care & Cultural Transformation. He was the founding  Director  of the Beth Israel Fellowship Program in Integrative Medicine, and teaches in the Beth Israel Residency Program in Urban Family Practice. Dr. Kligler is the author of Curriculum in Complementary Therapies: A Guide for the Medical Educator, and co-editor of Integrative Medicine: Principles for Practice, a textbook published by McGraw-Hill. He is also Co-Editor-in-Chief of the peer-reviewed journal Explore: The Journal of Science and Healing.