The influence of early life health and nutritional environment on later life health and morbidity

Melanie Luhrmann, Royal Holloway University of London and Tanya Wilson, University of Glasgow

(Project no. 1002047)

The project aims to conduct econometric analysis to investigate to whether, and to what extent, an individual's childhood nutrition and health environment influences later life mortality and morbidity.

Specifically we intend to examine the later life health outcomes, including mortality, of individuals born between 1930 and 1960. This period of study saw fundamental changes to the nutritional and health care environment of the population, primarily through the introduction of the National Milk Scheme in 1941, wartime/post-war food rationing, and the introduction of the National Health Service (NHS) in 1948. The Longitudinal Study provides a unique opportunity to examine later life health/mortality outcomes of individuals born immediately before and after these interventions. The analysis may yield insights important to public policy formation.

It is intuitive to expect that these interventions had a positive effect on childhood health and mortality, indeed examining aggregate level infant mortality statistics from the Office of National Statistics over this period reveals reductions in mortality concurrent with these programmes. However an important question remains as to whether any positive effects persist through the life course, which is the question we intend to address in this project.

Our proposed research strategy consists of three elements:

1) Comparing the health and mortality outcomes of individuals born in the immediate cohorts prior to the introduction of the National Milk Scheme (NMS) to those born afterwards. As the scheme was implemented at the national level, the statistical approach will take the form of a Regression Discontinuity Design, where we will allow for pre-existing trends in the outcomes to differ either side of the threshold (i.e. the timing of the scheme's introduction). This approach will also allow us to investigate the impact of pre-natal nutrition, as the NMS was targeted towards pregnant and lactating mothers, as well as young children. Using the timing of the scheme's introduction we will be able to differentiate between children who did not benefit from the scheme, those who received the milk supplements during infancy and early childhood only, and those who received both pre- and post-natal benefits.

2) A regression discontinuity design is also appropriate to examine the introduction of the NHS, by comparing individuals born in the period immediately before the introduction of the NHS to those immediately afterwards. Again from the timing of the introduction of the NHS legislation we will be able to distinguish between individuals who benefitted from the scheme from birth onwards from those who also received pre-natal care.

During the wartime and immediate post-war period food supplies were rationed. Many families supplemented their ration with home-grown food, which essentially implies that there was variation in food availability according to area of residence - specifically those in urban/densely populated areas would not have the opportunity to supplement their ration to the same extent as those in rural areas. Therefore to examine the overall impact of childhood nutrition we will use a difference-in-difference approach, where we will compare the outcomes of individuals according to geographical location of birth. We will also interact this information with the NMS and NHS introductions, which will allow us to examine the full picture of the impact of childhood nutrition and health environments on later life outcomes

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