This is the speech given by the researcher Jordi Sunyer when he was awarded an honorary doctorate by the University of Hasselt (Belgium) on 25 May 2023.
Science, claims to have identified that 55% of the causes of illness and death are preventable. If we control hypertension, glucose and cholesterol, eat fruits and vegetables, have a balanced caloric intake, do not smoke or drink alcohol, live in places with clean air and water, and do regular physical activity, we will have a longer life.
Interestingly, all these determinants are mostly caused by individual habits and by the neighbourhood or town where we live. Genetics have a smaller role.
So, very likely, if we made equitable public interventions addressed to modify our habits and environment, we could continue to extend life expectancy.
Such increase in life expectancy has started since the beginning of the industrial revolution, basically through the sanitation and the control of infectious diseases, a better nutrition; and, latter with interventions such as the smoking control. Banning smoking in public places reduced myocardial infarction by 15%.
If we made equitable public interventions addressed to modify our habits and environment, we could continue to extend life expectancy
The raise in life expectancy has been only reversed in some exceptional cases, such as the increase in alcohol consumption at the end of Soviet Union, or the recent opioid epidemic for painkillers in the USA or the Covid pandemic. Moreover, the raise in life expectancy has been stopped in some other rare circumstances, such as after the second world war.
So, the extension of human life in all societies is indisputable.
Though, has this gain in the life expectancy being translated in extending the years lived with good health and quality of life? The group of experts assessing the global burden of disease says there is no doubt that this is the case, despite the increase in some non-fatal diseases such as osteoarticular and mental diseases. Therefore, if we make preventive individual and collective health promotion efforts, we could live more years with good health and quality of life.
The improvement of urban air quality is a clear example.
When the Quality of the Air Improves
There are numerous studies that consistently show that air pollution during pregnancy reduce pre-natal growth, which is a predictor of a poorer development in childhood and high risk of diseases later in life
Indeed, my group, for example, found that levels of traffic pollution in the classrooms and the school courtyards of thousands of school children in Barcelona, could affect the growth of the brain. Those girls and boys who went to schools with better air quality had a better development of their brain function and the mental cognition.
Another significant piece of research was conducted by the Children Health Study in Los Angeles where each new generation breathed cleaner air mainly because the interventions in traffic, which was replicated by Ackerman’s group in Switzerland. As the air became cleaner, the respiratory performance and health of each new generation improved: lung volumes increased and the incidence of asthma and bronchitis decreased, independently of other temporal changes.
The WHO declared that air pollution was the number one health hazard among environmental threats, causing millions of deaths every year, and the loss of millions of years with healthy life and it was urged to improve air quality
At the other end of life, air pollution is associated with biological markers linked to dementia and Alzheimer's which reinforces the growing evidence that Alzheimer's can be caused among others by the levels of particles in the air.
In addition to morbidity, a seminal study by Pope and Dockery among the largest metropolitan areas in the USA, discovered that with air quality improvement (due to transport and industry interventions) life expectancy had been extended by more than half a year. A change in life expectancy comparable to the gains of new medications for the same period.
This discovery agrees with that of Prof. Nawrot who found that poor quality of the air was related to the shortening of the telomere length, which is a marker of molecular aging and hence longevity.
Overall, the WHO declared that air pollution was the number one health hazard among environmental threats, causing millions of deaths every year, and the loss of millions of years with healthy life and it was urged to improve air quality. And, therefore, better life expectancy and quality of life.
Only in a Healthy Planet Could Human Health Keep Improving
However, there is a paradox of great concern to the rise in the life expectancy. The accelerated improvement in life expectancy throughout the world and in all social strata, has come with the accelerated deterioration of almost all ecological parameters: water shortage, acidification of the seas, emission of greenhouse gases, as well as, biodiversity loss, impoverishment of the soil, desertification, increase of temperature, among many others.
This contrast between a global enhancement of human health and a deterioration of the health of the Earth is what has led many experts in public health to conclude that the indisputable improvement in human health, in spite of inequalities, is a result of eroding the natural earth systems and it is a mortgage for next generations, that, for example, will have to deal with our wastes such as CO2, that remains for more than two centuries in the atmosphere.
Even more, this environmental crisis is putting some of the planet's physicochemical systems beyond their regenerative capacities of the air, the water, the soil, to the level of crossing the point of no return.
Either human health goes hand-in-hand with the health of the planet, or it could be that increases in life expectancy and quality of life have peaked and may be regressing
Geophysicists and biologists remind us that crossing this tipping point of no return in terms of biodiversity loss or climate change can trigger a cascade of systemic changes that can lead to changing the conditions of life as we have known, and this could occur in an unpredictable period, sense and magnitude.
That is why human health is deeply interrelated with the health of the planet. That only in a healthy planet could human health keep improving.
Indeed, the benefits of nature restoration on health is already well established, beyond the expected benefits on mental health.
Therefore, either human health goes hand-in-hand with the health of the planet, or it could be that increases in life expectancy and quality of life have peaked and may be regressing.
New Ways of Thinking, New Knowledge, and New Governance
As said, we already have experiences of the reduction of life expectancy in the past. However, the challenges that the environmental crisis creates for us is more complex and systemic than these local examples, because of the magnitude of the hazard and because of the brevity of time that we have to react. These new challenges require new ways of thinking, new knowledge, and new governance
Thus, actions should reconcile human health and that of the planet, such as the promotion of active transport, not only because it improves human health by increasing physical activity and reducing the emission of particles into the air, but also because of favouring the health of the planet by reduction of greenhouse gases.
Coincidingly, a recent proposal by a well-known thinktank claims that governments should set aside 10% of health spending for preventive and public measures such as increasing cycle lanes, and anti-obesity strategies, the creation of non-emissions zones around schools, or by increasing greenness into the cities among many other co-beneficial interventions that they pursue energy decarbonisation, a sustainable food system or agreements in the environmental commons.
To assume that a minority will be protected by their wealth and will be able to benefit from new discoveries to artificially extend life seems naive in this perspective of a sick planet from which there is no escape
So, denying this systemic, global vulnerability and today's environmental emergency when making policy is a high-risk attitude for the prospects to follow improving our health for all.
To assume that a minority will be protected by their wealth and will be able to benefit from new discoveries to artificially extend life seems naive in this perspective of a sick planet from which there is no escape. Who could avoid brain degeneration due to poor air quality despite having the pill of eternal life?
In this context, therefore, the redevelopment of our cities and villages in order to improve our health and that of the planet is one of the most efficient and equitable strategies available to us. At least, until the miracle of a remedy for eternal life for all humanity without affecting the planet appears. Nothing less than an oxymoron.