The physiological reduction of stress is accompanied by a reduction in psychological risk factors and the burden of certain stress-related mental illnesses. Exposure to nature is also associated with lower incidences of other conditions, such as anxiety disorders and depression.
NATURE AS A CURE
Being in contact with nature promotes our physical and psychological well-being.
Several studies observe a reduction in stress and depression, favored by the natural environment and, conversely, an improvement in self-esteem, the feeling of happiness or even creativity.
Nature heals our ailments and, more than that, it also improves our cognitive abilities and functions, reducing fatigue and restoring our attention span, so strained by daily life. It also contributes to our physical well-being: reduction of pain, blood pressure, obesity or even acceleration of healing and prevention of certain diseases.
In short, nature is not simply a necessary substrate in which human cultures take root, but a soil that influences our daily lives and which, perhaps, is precisely what allows these cultures to grow and grow.
WHAT NATURE ARE WE TALKING ABOUT?
The nature in question can take very diverse forms: it can be elements of nature (stones, water, wind), fauna, flora, landscapes (sea, mountain, forest ), which do not necessarily belong to a biodiversity which acts in a defined ecosystem.
For example, in 1984, a study already showed that patients with a window to the outside healed more quickly following operations than other patients without such a view.
Are a few green plants or a photograph of the sea enough to feel the benefits of nature? The question is important since it potentially has consequences in terms of environmental protection choices and public health policy.
A NATURE RICH IN BIODIVERSITY
Studies converge on the idea that a nature in good health, that is to say rich in biodiversity and functional, ensures good human health.
This observation may seem obvious, however, the more systematic convergence of debates between environmental and social issues is quite recent. The media coverage of the discussions around the renewal of the European license for glyphosate, a herbicide widely used in agriculture, or more broadly the explosion in demand for organic products, reflect the growing sensitivity of public opinion to these issues. When it comes to direct or dietary exposure, the relationship between degraded natural systems and negative effects on human health is easy to imagine.
The added value on health and well-being, provided by a rich environment compared to scattered elements of nature, has yet to be explored.
One area in which the benefits provided by exposure to biodiverse environments are clearly illustrated is in chronic allergies and inflammatory diseases. Exposure to a multiplicity of natural habitats normally allows the development of immune responses to allergens and other factors that can cause disease. The lack of exposure to microbes, especially in early childhood, can lead to poor acclimatization of the body's microbial community, and an unexpected reaction to certain particles.
The environment of individuals must therefore include a diversified source of microbes allowing adequate inoculation.
According to the so-called biodiversity hypothesis, the decrease in human exposure to the microbial population would affect the microbiota, which would lead to the development of different diseases.
A DOSE OF NATURE
The current challenge lies in the fact that a healthy nature is not just about an environment devoid of chemicals. The destruction of natural habitats and species, the overexploitation of resources or even climate change are also factors of human origin which contribute to making nature less diversified and alter its functioning; and in turn, jeopardize our health and well-being.
In what relationship with nature must one be engaged in order to perceive its benefits? Should I look at it or touch it? And with what regularity?
Here again, the questions are important, because they are part of a contemporary context of changing relationships with nature, due to urban and sedentary lifestyles. We spend less and less time outdoors and, for most of us, in an impoverished natural environment, to the point that some authors refer to it as “the extinction of experience”.
The parameters that influence human well-being are sometimes difficult to isolate from the whole of the lived experiences of the subjects. This is why some authors propose as a framework for research the concept of “dose” of nature, making it possible to associate different durations, frequencies and intensities of experiences and exposure to nature. The different parameters that make up this “dose” are then processed according to the health of the individuals. The importance of the benefits resulting from the relationship with nature would thus depend on the dose of nature received.
TO SEE LIFE IN PINK
Nevertheless, the complexity of the mechanisms of natural benefits to human well-being still eludes comprehension. Why does nature do us good? To To this question, the “biophilia” hypothesis is put forward, postulating that human beings have an innate tendency to seek connections with nature and other forms of life. This interest in nature would be the product of a biological evolution allowing the best possible adaptation to the environment.
The rapid decline of natural habitats and the collapse of the diversity of animal and plant species presents a worrying scenario for human well-being. In addition, contemporary lifestyles result, for a large number of individuals, in a lower direct exposure to the natural environment.
If our well-being depends in part on the quality of our connection to nature, we can wonder about the human and environmental consequences of this "disconnection" that is beginning. To reverse this trend, the development of scientific research must be accompanied by the implementation of actions in the field.
It is necessary to rethink the approach to management policies, particularly in the field of urban planning, where it seems urgent to bring nature into the city, to protect and promote biodiversity in these spaces.
At the same time, the field of education also bears a responsibility in taking measures to encourage young people to develop and maintain a relationship with nature as early and as regularly as possible.
While the preservation of biodiversity is struggling to fit into the agendas, the recognition of human health and well-being as an element strictly dependent on favorable environmental conditions could be a decisive argument.