Many of us know that being in pleasant natural surroundings can be relaxing. A walk in the countryside or through a leafy park feels as though it is doing us good.
A study published in the Lancet was an example of science confirming this intuitive knowledge
The study by Richard Mitchell and his colleagues at Glasgow University looked at the number of deaths occurring in low and high income groups. The researchers found that the gap in terms of death rate between high and low income groups was half of what would be expected in green environments compared with urban areas.
It’s been known for a long time that those on low incomes are more likely to suffer illness and early death than those on high incomes. Many reasons have been put forward to explain this: inadequate diet amongst the poor, stressful environment – high crime or noise for example and better access to healthcare among the wealthy.
It could be that the lack of crowding and lesser likelihood of crime in leafy areas gives rise to less psychosocial stress; in the west the poor are predominately urban dwellers. The authors of the study suggest that not only do open green areas afford more opportunity for exercise but that the exercise they do take is more beneficial because stress levels are lower.
Psychosocial Stress and Illness
Psychosocial stress is known to be an important risk factor in the production of hypertension. We know that hypertension is in turn a risk factor for coronary artery heart disease and stroke. This would go some way to explain the findings of the study.
But why should green areas reduce stress levels in most people? One would expect stress levels to be lower if we are among people we know and like – family and friends, if we have reasonable living accommodation and have enough money to live on. These factors should be enough to keep our stress levels low (barring family disputes of course) whether or not we are in a green environment.
Natural Environment
It’s been known for a while that captive animals are much more healthy if they can be kept in areas that mimic as far as is possible their natural surroundings: zoos all over the world spend much time and money in trying to create ‘natural environments’ for their animals.
What is a natural environment for human beings? It’s not brick houses or glass buildings: we’ve only been in these for a very short part of our evolutionary history. Humans evolved in open space: around trees and grass and on beaches and near lakes (many people find being near open water relaxing). To the cells in our bodies these surroundings are normal: they are where we should be.
Natural environments can of course be bleak or even dangerous. But humans are adapted to even the unpleasant aspects. It can be refreshing and probably healthy to feel the wind, rain and cold on our bodies – up to a point anyway. We are also programmed to deal with danger so that when required our stress response is triggered – our ‘fight or flight’ reaction. In urban environments, surrounded by strangers our stress response may be continually stimulated at a low level thereby providing a constant stream of stress hormones. There is normally much more space between people in green areas.
As often as you can take a stroll in green areas; it will undoubtedly improve your health. If however you have any concerns about health your first walk should be to your doctor’s clinic.
Resource
Effects of exposure to natural environments on health inequalities. R Mitchell et al, The Lancet Nov.8 vol 372 no.9650
