Can you imagine being happy in a world without nature? A growing amount of research studies show that nature is essential for human health and well-being. Whether we realise it or not, humans are interconnected with nature. Spending time in nature, even during short times, reduce feelings of stress or anger. Furthermore, is helps to feel more relaxed and improve self-confidence and self-esteem. However, exposure to nature not only makes you feel better emotionally, but it contributes to your physical health. It helps by reducing blood pressure, cortisone or improving our immune system.
Nature effects on physiological function
A research study conducted at Nippon Medical School, showed that spending time in the forest enhanced the number and activity of human natural killer (NK) cells about 50 percent. This type of white blood cells supports the immune system and play an important role in lowering risk of cancer activity, improve immunity and lower blood pressure. The explanation is found in the emission by trees and plants, of aromatic volatile compounds called phytocides. These compounds, when inhaled, significantly increase NK activity and percentages.
Further, a study conducted at the University of Queensland found that people who spend 30 minutes (or more) each week in outdoor green spaces had lower rates of high blood pressure. Similarly, other studies found that walking in forest environments promote lower concentrations of cortisol, lower pulse rate and lower blood pressure compared to walking in city environments.
Nature effects on mental health
Spending time in nature has also multiple impacts on cognitive functioning, emotional well-being, and other dimensions of mental health. For example, a study found that people who went on a 90-minute walk through a natural area (forest or nature park) reported lower levels of rumination, a hallmark of depression and anxiety. Moreover, they showed reduced neural activity in an area of the brain linked to risk for mental illness compared to those who walked through an urban area.
Although the exact mechanisms of how nature helps mental disorders are unclear, various factors play a role. For example, the air in forested and mountainous areas, and near moving water, contains high concentration of negative air ions. These are thought to reduce depression among other effects. Interestingly, another recent research showed that listening to natural sounds also improve mental health. It helps by decreasing pain and stress, and enhancing mood and cognitive performance.
However, having green spaces is not all that matters. Biodiversity also plays an important role. A new study conducted in Germany, found a significant positive relationship between plants and bird species richness and mental health.
Implication for urban development
All the results mentioned above, are just some of the multiple benefits nature provides to human health. Accessible natural areas and green spaces are, therefore, vital for physical and mental health in our rapidly urbanising world. For example, Wilderness therapy provides great benefits for human health, as mentioned in a previous post. In addition, providing green areas in cities might be an inexpensive, powerful public health intervention. City planners and developers should put especial efforts to increase access to nature in low-opportunity neighbourhoods to address significant inequities.