Health does not depend only on DNA. Environmental, climatic and behavioural factors, such as heatwaves, urban pollution, and prolonged evening exposure to screens and artificial light interact with genetic predisposition, influencing the body’s biological processes throughout our lives.
This is the key message of the conference Exposome Research: Finding Solutions for a Healthy Planet, promoted by theAlma Mater Institute on Healthy Planet, a strategic interdisciplinary research centre of the University of Bologna, which brought together international experts on 17 and 18 June to discuss a new paradigm in medical research.
The focus of the discussions was on the concept of exposome, the imprint of the environment on our health. The exposome is the sum of the environmental exposures an individual experiences over the course of a lifetime, from the prenatal stage until death. This, together with genetic makeup, determines health and disease trajectories.
Emerging exposures: light, climate and biological rhythms
Among emerging exposures, artificial light during the evening and night-time hours is becoming increasingly important, reflecting its growing prevalence in urban environments and in everyday use of digital devices.
“Light is one of the main synchronisers of biological rhythms. Night-time exposure can interfere with circadian rhythms, affecting sleep, metabolism and hormonal regulation”, says Valerio Carelli, Director of the Centre and Professor of Medical Genetics at the University of Bologna. “For millions of years, our human rhythms have been synchronised with the natural cycle alternating light and darkness. Today, screens and artificial lighting alter this balance, with effects on vulnerability to various diseases in the long term.”
Alongside light, heatwaves represent a further environmental stress factor, with significant impacts on fragile segments of the population, such as elderly people and children.
A paradigm shift in medicine
“Health is built through continuous interaction with the environment”, Prof. Carelli explains. “This is why we are moving beyond the ‘one-to-one’ model between cause and disease: it is necessary to observe the body over time, integrating genetic, environmental and clinical data collected longitudinally.”
Research is therefore shifting from cross-sectional studies based on a single observation of large patient cohorts to repeated monitoring over time. “Rather than observing 500 people only once, we need to observe fewer individuals many times throughout their lives”, Carelli says. “It is in the dynamics of exposures and biological responses that the onset of diseases can be understood.”
The traditional organ-based model is giving way to a more integrated approach. “Organs communicate with one another: signals originating in one body region can provide valuable information about other systems”, Carelli says.
Artificial Intelligence and advanced biological models
The growing complexity of the available data makes the role of AI central. It can be used to analyse multi-level information and identify correlations that are not apparent with traditional approaches.
In parallel, research is developing advanced experimental models such as organoids, mini cellular structures derived from patients that make it possible to study in vitro pathological processes and responses to environmental and pharmacological stimuli. “In the Centre’s laboratories we can recreate small organs and use them to simulate the impact of environmental exposures”, Carelli explains. “This opens up new prospects for understanding disease mechanisms and for personalised medicine”.
European projects: from healthy cities to oncology
The conference presented the results of several European projects that integrate medicine, the environment and urban sciences.
The first results of the eMOTIONAL CITIES project show how, by modifying certain elements of the visual experience of a simple walk in an urban environment, it is possible to influence brain activity, impacting emotions and cognition. The project proposes an integrated model of investigation that links neurosciences and urban planning sciences. The results complement the experience of the ENLIGHTENme project, coordinated by the University of Bologna, dedicated to the impact of light on urban contexts, which tested urban lighting solutions designed to promote wellbeing, also through the co-design of public spaces with citizen participation.
The Catalyse and Trigger projects highlight the fact that it is possible to predict and mitigate the effects of extreme climate events, making the healthcare system more resilient in the face of these recurring emergencies.
The results of the ORCHESTRA project illustrate the exposome paradigm well. The study of genetics — or, more accurately, of its many branches — human nuclear DNA, human mitochondrial DNA and the metagenome of the microorganisms that live within the human body (microbiome) - can explain a large part of the variable severity with which a viral infection such as COVID19 has affected humans, from an asymptomatic infection, to one comparable to a mild flu, through to severe infection with hospitalisation and possibly death.
The Bioeconomy paradigm offered further insights into how the exposome and related research can have positive impacts on technological and regulatory innovation, with growing political and economic implications, making them a potential driver of development.
The conference concluded with a session dedicated to oncology, a field in which the role of the exposome is now well established. On the one hand, the ability of some healthcare systems — France being a case in point — to support long-term epidemiological studies is essential for assessing the impact of the exposome on health. On the other hand, cutting-edge research on the longitudinal analysis of faecal microRNAs as biomarkers for different types of cancer, as well as for tumour progression and staging, could be applied to patient stratification.
Conclusions
Exposome medicine represents an evolution in the way human health is interpreted: no longer either genetics or the environment alone, but a dynamic complex of interactions over time.
“There is no one-size-fits-all solution: personalisation and understanding of individual differences will be increasingly central to the medicine of the future”, Carelli says.
“Investing in research means investing in technology, innovation and the ability to address the health and environmental challenges of the coming decades.”
