Popular in Japanese culture since the 1980s, Shinrin-yoku, roughly translated as "forest bathing," is the spiritual practice of opening one's senses to nature. According to shinrin-yoku.org., the scientifically-proven benefits include increased flow of eros/life force, increased capacity to communicate with the land and its species, increased flow of energy, reduced stress, deeper and clearer intuition and and an overall increase in a person's sense of happiness.  Stress reduction is one reason these benefits arise, but studies show that air quality is also a factor; microbes and fragrances that make up natural antibiotic compounds found in forest air increase the presence of Natural Killer cells in the body. According to the Nippon Medical School Department of Hygiene and Public Health, "Because NK cells can kill tumor cells by releasing anti-cancer proteins, the above findings suggest that visiting forest parks may have a preventive effect on cancer cell generation and progression."