|Path along bamboo forest in Kyoto, Japan|
Additional studies by Japanese scientists explored the physiological effects isolated according to the seperate senses of smell, sound, feel, and visual stimulation, which partially reflect the nature of the forest. Certain odors seemed to have significant impact on relaxation and stress reduction, such as Taiwan cypress essential oil, hiba oil, cedrol and limonene. While soothing sounds didn't make much of a physiological difference on relaxation, the sound of a dentist drill significantly increased participant's blood pressure levels.
One study indicated that shinrin-yoko was useful in the lowering of blood glucose levels for persons with diabetes. This lowering occurred after either a 3 or 6 kilometer walk, depending on the participant's physical ability.
The researchers suggested that humans feel a sense of relaxation with the natural environment since that is where we originated. Conversely the modern "artificial" society has become stressful since it is not as natural.
Bamboo pictures were taken during a 2008 family trip to Japan.