Like pets, indoor plants have long been known to reduce stress. The findings aren't anecdotal, either.
A 2016 study by Korean and Japanese researchers reported in the Journal of Physiological Anthropology set out to find whether interaction with indoor plants can alleviate the "great deal of stress to modern people" caused by "information technology." The male young adult subjects were divided into two groups, one tasked with repotting an indoor plant and the other with completing an assignment on a computer. When their tasks were completed, the groups switched roles, and the researchers found "significant" differences in blood pressure and heart rate variability that showed "interaction with indoor plants may reduce psychological and physiological stress by suppressing autonomic nervous system activity."
And the landmark 1989 NASA Clean Air Study revealed that plants are the most efficient (and cost-effective) method of reducing indoor air pollution, removing such toxins as benzene and formaldehyde from the air.
