What is missing in linking overarching determinants like socio-economic status to health and poor ageing is an understanding of the intermediate mechanisms and biological pathways that relate low SES with deterioration of organic parameters. For example, research on immune markers in the Whitehall II study has shown that glucocorticoids and inflammation may in part explain how the body mediates the effects of low SES thus leading to disease, and this is partly independent from common/known risk factors. Also, evidence has accumulated on the key role of epigenetic modifications induced by the experience of psychosocial adversity in initiating physiological dysregulations.
The approach based on intermediate biomarkers is more powerful than the one based on traditional risk factors alone because
- it may explain subtle chronic effects acting throughout the life-course (like chronic stress) that are not easily captured by questionnaire-based epidemiology;
- it allows tracing signals that start in early life down to health effects in later life;
- it provides an approach to the discovery of new pathways and causes of disease, particularly through the new omic technologies.
By analysing intermediate biomarkers potentially involved in various diseases, this approach is likely to reveal some common – and currently unknown – roots of many non-communicable diseases, thus improving our ability to implement successful interventions, with a wide range of actions.