David JP Barker was a physician, a biologist and one of the most influential epidemiologists of our time. His ‘fetal programming hypothesis’ (‘Barker Hypothesis’) transformed our thinking about the causes of diabetes, cardiovascular disease and cancer. He challenged the idea that they are explained by bad genes and unhealthy adult lifestyles, and proposed that their roots lie in the early life environment: “the nourishment a baby receives from its mother, and its exposure to infection after birth, determine its susceptibility to chronic disease in later life”. By permanently ‘programming’ the body’s metabolism and growth, they determine the pathologies of old age. He set out this theory in a series of books, starting with Mothers, Babies and Disease in Later Life in 1994. His initially controversial, but now widely accepted, ideas have stimulated an explosion of research worldwide into early development and later disease (‘Developmental Origins of Health and Disease’ or DOHaD). David thought that “the poorer health of people in lower socio-economic groups or living in impoverished places is linked to neglect of the welfare of mothers and babies”. He argued that to pull back the modern epidemics of chronic disease we should prioritise the health and nutrition of girls, pregnant women and infants.
These ideas developed on a background of David’s knowledge of biology. His science teacher at Oundle School, Ioan Thomas, encouraged his enthusiasm for natural history, allowed him to roam the countryside hunting for beetles, and gave him unlimited access to the labs. On leaving school, he led a plant collection project in Iceland for the Natural History Museum. While studying Medicine at Guy’s Hospital, he did a BSc in Comparative Anatomy, Embryology and Mammalian Biology, and was taught by the zoologist JZ Young. David’s first paper, on testosterone and bone density, was published in Nature when he was still a student.
After qualifying in 1962, David became a research fellow under Tom McKeown, a social epidemiologist, at the University of Birmingham. His PhD thesis, Prenatal Influences and Subnormal Intelligence, was a harbinger of his fetal programming work, but he initially set off in a different direction. With an MRC grant, he studied Mycobacterium ulcerans infection (Buruli ulcer) in Uganda, working from Makerere University. The project was curtailed when President Amin plunged Uganda into crisis, declaring westerners unwelcome. David had to gather up his young family and drive at night into neighbouring Kenya, ostensibly for a holiday but actually in flight. But he had done enough research to establish a link between the wounds caused by razor sharp reeds growing near the river Nile and transmission of Buruli Ulcer, previously considered an insect-borne disease. He had also learned the importance of observing how people lived and listening to them, to understand disease.
In 1972 David moved to Southampton, where he stayed for the rest of his career. He worked as a physician at the Royal South Hants Hospital, and recruited able clinicians to join his research. In 1979 he, Donald Acheson and Martin Gardner established the MRC Environmental Epidemiology Unit and David became Professor of Clinical Epidemiology. He was an inspired teacher, and with Geoffrey Rose set up an annual course in Southampton (Epidemiology for Clinicians) which still runs today. He wrote a series of books (Practical Epidemiology, Epidemiology in Medical Practice and Epidemiology for the Uninitiated) which introduced epidemiology to a generation of researchers.
In 1984 David became Director of the Southampton MRC Unit. His research into the aetiology of thyroid disease, Perthes’ disease, Paget’s disease, appendicitis and chronic neurological disease, led him back to evidence of nutritional and infective influences in earlier life. He suspected that such influences cause the rapid waxing and waning of disease, for example the mysterious disappearance of rheumatic heart disease and new epidemic of coronary heart disease. The Unit’s detailed mapping of mortality (Atlas of Mortality for Selected Diseases in England and Wales, 1968-1978) led to his observation that areas with more infant mortality in 1910 had more cardiovascular deaths in 1970. He and statistician Clive Osmond confirmed strong geographical correlations between neonatal mortality and death from coronary heart disease and stroke decades later. He concluded that poor fetal nutrition was causally linked to later disease, and devoted the next three decades to a tenacious pursuit of evidence to support this.
He hired a historian, and searched for old birth records. With colleagues in Southampton and Cambridge, he showed that people of lower birth and infant weight had more cardiovascular disease and diabetes in middle age. With the Helsinki birth cohort group, he related patterns of childhood growth to these diseases. With colleagues in India, he showed similar relationships in developing populations. With the Dutch Hunger Winter group in Amsterdam, he showed that exposure of mothers to famine left a legacy of ill health in their children. He collaborated with physiologists in Adelaide, Auckland and Toronto who were studying fetal development in animals, harnessing strong evidence that early life undernutrition had permanent effects, on all body systems. The connections he made between the worlds of physiology and epidemiology were the forerunners of the International DOHaD Society and congresses.
There were some aspects of modern epidemiology that David disliked. He disagreed that consistency of findings across randomised controlled trials was the highest form of scientific evidence, because he thought that it was unbiological to expect similar findings in widely different settings. He disliked the emphasis placed on testing the null hypothesis, believing that new discoveries would be impeded by our inability to hypothesise the unimaginable. He thought that too much was spent on genetic research, to the detriment of research into environmental causes of disease. He was anxious to press ahead with action to improve the care of mothers and babies, without waiting for the mechanistic details, citing the epidemiologist John Snow who stopped an epidemic of cholera in London by removing the handle from the Broad Street water pump long before Vibrio cholerae was discovered.
David retired as Unit Director in 2003, but continued to work there (now the MRC Lifecourse Epidemiology Unit) and helped establish the Southampton Initiative for Health, to seek practical ways of improving maternal health. He became visiting professor at Oregon Health Sciences University, Portland, a centre for placental research, and Emory University, Atlanta, studying the biology of human growth. He made his second documentary with the BBC Horizon team, The Nine Months That Made You, explaining fetal programming for a general audience, in 2011.
David was an inspiring leader. He was a brilliant raconteur and enormous fun. His single-minded pursuit of science left little time for other interests, but he enjoyed piano playing, painting, fishing, cooking and golf. He was a deeply private, thoughtful and caring man, for whom family life was central. His first wife Angela, with whom he had five children, died in 1980. He married Jan in 1983 and welcomed her three into his family. Together they created a unique environment at their home in Hampshire, which housed four generations and became a centre for scientific work, with visitors from around the world. Jan supported David in all his endeavours, indeed her informality and warmth were central to his research partnerships. He is survived by Jan, eight children and 13 grandchildren.
David died suddenly on 27th August 2013 at the age of 75. His discoveries created a new field of research and had a huge influence on the scientific world. He published over 500 papers and 10 books, became a Fellow of the Royal Society, and was awarded a CBE. His many honours included the Royal Society Wellcome Gold Medal (1994), Prince Mahidol Award (2000) and International Epidemiology Association Richard Doll Prize (2011).
There will be a memorial service for David at Romsey Abbey, Hampshire at 12 noon on 12th November 2013.
— Caroline Fall, Clive Osmond 9th September 2013 (from the International Journal of Epidemiology)