Radboud University historians and ageing researchers from Leiden University Medical Center (LUMC) will be receiving a grant of over 800,000 euros for research into the influence of 'the family' on child mortality, fertility and life expectancy over the last two hundred years. NWO (The Netherlands Organisation for Scientific Research) awarded the grant under the terms of the Vrije Competitie Geesteswetenschappen ('Open Competition in the Humanities').
Historical demographer Dr Angélique Janssens (History, Radboud University) and biologist Prof. Eline Slagboom (Molecular Epidemiology, LUMC; initiator and research leader of the Leiden Longevity Study) will be investigating the effect of the family on the risk of dying young or living to a very old age. This study of child mortality, fertility and life expectancy within families during a period of two centuries is unique in the whole world.
Hereditary and other shared factors
'We are looking at the influence of both hereditary and shared environmental factors in families', Angélique Janssens explains. 'The social group people belong to is important, but also where they live and whether certain infectious diseases are common in such geographical areas. In the nineteenth century, for example, malaria was common in the province of Zeeland, whereas elsewhere people were being exposed to tuberculosis.' Janssens has already shown that infant and child mortality in the past was largely confined to a relatively small group of families, which suggests that family factors were playing an important role.
Long lines of descent
Over the last ten years, Slagboom's research in longevity families has demonstrated that specific hereditary factors within families determine whether people survive to high ages. 'For the new research we need long lines of descendancy extending over several generations', Eline Slagboom said. 'That's why this interdisciplinary project covers two hundred years, a period in which the average life expectancy in the Netherlands rose from around 35 to 83 years.'
Five years of research
As part of a project entitled Hoe bepalen genen, ziektekiemen en sociaal kapitaal je levensduur? ('How genes, pathogens and social capital determine your life expectancy'), the historical demographers and epidemiologists are collecting data on Dutch families over several generations from historical databases. They compare these data with DNA material from living members of families in which people, generation after generation, have lived exceptionally long. During the next five years, three PhD candidates and project leaders Angélique Janssens and Eline Slagboom will be using the grant for research and for activities such as constructing special databases.