The developmental origins of health and disease: an overview

The concept of developmental origins of health and disease (DOHaD) grew from the earlier concept of fetal origins of adult disease (FOAD) (reviewed in Barker 1995, 1998). There are two important reasons forthechange.Thefirstresults fromthelargeamount of research (much of it reviewed in this book) showing that the early life events which determine in part the risk of later disease occur not only in the fetal period specifically, but throughout the plastic phase of development. In this respect the use of the word ‘development’ is helpful because it implies not only effects operating during early stages of embryonic life (usually the preserve of developmental biology) but also those in infancy. Secondly, the DOHaD terminology emphasises that this area of science has implications not only for disease, and its prevention, but also for health promotion. The latter is of great importanceinpublichealthandeducationprogrammes in many parts of the world. But the accent on ‘developmental origins’ is more than just a flag of convenience under which several disciplinesmay sail: it represents a fundamental shift in thinking about theway inwhichearly lifeprocessesaffect later health and disease in humans. Previously, proponents of FOAD championed the viewthatprenataleventswereofutmost importance. Adopting thispositionwas tacticallynecessary in the battle (nowwon) togainwidespreadrecognition that theaetiologyofmanychronicdiseases, suchas coronary heart disease (Barker andOsmond1986), type 2 diabetes (Ravelli et al. 1998) or osteoporosis (Cooper et al. 2002), lay not only in genetic predisposition or in adult lifestyle, but also in the ways in which early life events could affect subsequent biology. As a result, both epidemiologists and experimentalists have expanded the period of interest to that around conception (Cnattingius et al. 1998, Kwong et al. 2000, Inskip et al. 2001, Bloomfield et al. 2003, Robinson et al. 2004, Crozier et al. in press). In parallel, other clinical and basic scientists were stressing the importanceof thepostnatal environment during suckling, infancyandchildhoodinsettinganindividual on the path to health or disease (Eriksson et al. 1999, 2003, Singhal et al. 2002, 2003). At times, these two schools of thought appeared to be at loggerheads, and the resulting conflict did little to promote understanding of the importance of the field that they shared. Development is a continuum extending on either side of birth – consider the wide variation inmaturation at birth in different species. More recently, the recognition that the field of evolutionary developmental biology (‘evo-devo’) has enabled the development of a broader understanding of the phenomenon and, in turn, studies of the DOHaD phenomenon have led to new concepts in evo-devo biology. Both these advances in theoretical thinking and new experimental observations allow recognition that both preandpostnatal environmental factors play vitally important roles, and that what matters most is the degree of match/mismatch between