As a material, wood provides positive benefits to health by lowering stress reactivity. Stress is an unavoidable facet of modern life and is harmful to our health. It acts on the body by over-activating the autonomic nervous system. Stress is linked to illnesses such as heart disease, arthritis, and diabetes, and has addition negative effects on mood, memory, and cognitive performance.
By lowering our body's stress reactivity, wood exerts both positive psychological and physiological effects. This is a cornerstone of biophilic design-- incorporating natural materials and elements such as nature views, sunlight, and greenery in architecture and objects. Structures and materials under the biophilic design principle seek to evoke the effect of natural objects on humans without being exact copies. Exerting a positive effect on mood is linked to better health outcomes and immune system function.
Specific elements of biophilic design include viewing nature, natural sunlight, indoor plants, and the use of wood in built environments. Many studies have linked the presence of these factors to improved health outcomes. For example, patients recovery from surgery need less pain medication and felt significantly less stressed when placed in brighter rooms (Walch et al.), and patients with depression required less days of treatment when assigned to a sunny room instead of a dimmer room (Beauchemin and Hays). Short-term memory and temporal orientation is improved in other studies on depression when patients are situated in lit spaces during the day (Kent et al.). In workplace settings, access to increased light is associated with increased job satisfaction (Boyce et al.).
Wood has dual benefits in biophilic design as it is both a natural material and a building material with excellent properties. In other words, wood is both functional and biophilic, and can exert positive effects even in settings where nature views and sunlight is not available. Studies in this new field indicate that the presence of wood lowers autonomic stress reactivity and improve health and productivity outcomes. For example, adding cedar wood to hospital walls reduced the stress cortisol levels of patients compared to the original concrete walls (Ohta et al.). Students in wood-dominated classrooms and works in wood offices experienced indications of increased parasympathetic nervous system activation; the parasympathetic nervous system acts to reduce stress and aid in healing and recovery (Kelz et al.; Fell). Another study found that blood pressure dropped in people facing a wall finished in wood versus those who faced a white steel wall (Sakuragawa et al.).
The evidence supports the conclusion that we are healthier, happier, and more productive when in environments that include or evoke nature. Lower stress reactivity results in measurably lower heart rate and blood pressure, lowered pain perception, and increased concentration and recovery. Even in indoor environments where nature views, plants, and natural sunlight are not present, wood has been linked to the same responses and can serve to reconnect us with the health benefits of being around nature.