The role of behaviours in the emergence of health inequalities

Lifepath researchers gathered all the evidences on the role of health behaviours in explaining socioeconomic inequalities in health in a systematic review published on Preventive Medicine, which is the first study to provide a complete and comprehensive synthesis on the factors influencing the contribution of these behaviours to the socioeconomic gradient in health. They focused their attention on four of them – smoking, alcohol consumption, physical activity and diet – and restricted the considered health outcomes to cardiometabolic disorders and mortality. 

While they confirmed that health behaviours contribute to the socioeconomic gradient in health, they also shown that such a contribution may vary greatly due to the unequal distribution of these behaviours across socioeconomic groups in given socio-demographic, regional and cultural contexts. This differences in the behavioural socioeconomic patterning is also influenced by health outcomes – smoking, for instance, would likely provoke respiratory diseases, malignancies and atherosclerosis while obesity tends to be more related to dietary patterns and physical activity – and methodological differences between included studies.

As Lifepath researchers point out, “an overall challenge regarding the socioeconomic gradient in health would be to identify all the mediators involved in this association, such as psychosocial factors, material conditions, environmental exposures or work conditions in order to provide a global and complete understanding of mechanisms underlying socioeconomic inequalities in health”.

Lifepath researchers thus hope for their results to encourage the implementation of interventions targeting health behaviours, as they may reduce socioeconomic inequalities in health and increase population health.

Lifepath as a positive example of research in health inequalities

Ten years ago, as the financial crisis spread across the world, the World Health Organization’s Commission on Social Determinants of Health released its final report. Led by Sir Michael Marmot, the commissioners claimed that the “unequal distribution of health damaging experiences” was associated with the global imbalances in the distribution of power and money. Ten years later, a new reportfrom the same commission, addresses the topics of health inequalities and social justice, and calls on the WHO and all governments to lead global action on the social determinants of health with the aim of achieving health equity.

In a commentary on Critical Public Health, Ted Schrecker – professor of global health policy at the Institute of Health and Society, Newcastle University – highlights some key developments in this decade on such a topic. He mentions the increase of studies focused on social determinants of health, the growing recognition of the political origins of health inequality in global health policy analysis, and the advances made in understanding the physiological mechanisms by which chronic stress associated with privation and insecurity impairs health.

In his analysis, Schrecker also mentions “the remarkable Lifepath consortium of cohort studies linking epidemiology and biological markers over the lifespan”, since “Lifepath investigators, like earlier commentators, note the limitations of a focus on behavioural risk factors and have underscored this point in a recent systematic review”. Schrecker claims that initiatives like Lifepath will help to expand the amount of evidence in support of the WHO Commission’s perspective, which is of paramount importance in the future debates over global health policies and growing inequalities.