What is the Exposome?

Some basic definitions first ...

The exposome describes the totality of environmental exposures across the life course — from conception to old age.

These include chemical, biological, physical and psychosocial factors from food, air, water, lifestyle and the built environment.

Unlike the largely fixed genome, the exposome is dynamic and continuously shaped by our surroundings.

Understanding it is key to explaining chronic diseases, cancer and differences in health outcomes between individuals.

  • https://archive.cancerworld.net/
    Original definition of the exposome
    All exposures from conception onward, including those from lifestyle, diet, and the environment
    Christopher Wild, International Agency for Research on Cancer, WHO
  • https://bigpicturescience.org/segment/gary-miller-exposome
    An expanded defition of the exposome
    The cumulative measure of environmental infleunces and associated biological responses throughout the lifespan including exposures from the environment, diet, behavior, and endogenous processes
    Gary W. Miller & Dean Jones, Columbia University

Why the Exposome matters for our health?

Epidemiological studies show that genetic factors explain only a limited share of disease risk — typically less than 30%.

In contrast, environmental exposures captured by the exposome account for the majority of risk, in some cases up to 90%.

Most drivers of chronic disease therefore arise from the environments we live in — including diet, chemical exposures and psychosocial factors.

Understanding these patterns is essential for preventive and personalised health.