Monday nights episode of the BBc two programme Horizon was gripping. It was the story of a piece of science that began with an English G.P called David Barker, making an observation that birth weight could be linked to health outcomes in later life. He then doggedly pursued that observation to gather data from around the world in long term and systematic studies.
Low birth weight is defined by the World Health Organisation as below 2500 gms or 5.5 lbs, and is often associated with socio economic deprivation. Dr Barkers seems to have shown that low birth weight has a predictive power for what were consideredas chronic ‘lifestyle’ disease such as diabetes, cardiovascular disease and ostearthritis. He also found a gradient effect – so 6lbs is better than 5 lbs but 7lbs is better than six and so on.
An Indian doctor used this observation to discover why Indian people who do not appear overweight and get plenty of physical activity had high rates of diabetes and cardiovascular problems. These diseases are associated with overnutrition and lack of exercise in western nations. He found that low birth weight predicted an increase risk of diabetes and heart disease in Indian people. The cause seemed to be that the bodies of low birth weight children are laying down more fat – so that though they appear thin they are in fact carrying as much hidden fat as westerners who develop these diseases.
A Dutch scientist examined the war time records of birth weights during a five month famine linked to the activity of the retreating German army. Those children that were in utero at the time of the famine as adults suffered more poor health than their sibling who were born before or after the famine period. Hence the predictive effect of low birth weight is not a consequence of genes.
Lots more research is taking place but it certainly seems to make a much stronger case for the most importantperiod of life being the nine months before birth. It also shines a new light on the importance of maternal nutrition. The following is a summary of the research that has grown from David Barker original hypothesis about birth weight
Recent findings have shown that a woman’s body composition and diet at the time of conception and during pregnancy have important effects on the subsequent health of her offspring. The risk of later chronic disease is further increased if a baby has low weight gain after birth so that at two years it is thin or stunted. After the age of two, rapid gain in fatness further increases the risk of later coronary heart disease, hypertension and type 2 diabetes. These finding point to the importance of:
- protecting the nutrition and health of young women before and during pregnancy,
- protecting the growth of infants,
- avoiding rapid increase in fatness after the age of two years, especially in children who were thin at around two years of age, as part of the strategy to prevent chronic disease in later life.
Just think of the policy implications – at the moment Scotland provides for free prescriptions to treat disease that might be prevented by better maternal nutrition, but we means test access to free vitamins and support for maternal nutrition. We educate about contraceptives but do we educate prospective parents, and young women in particular, about how to prepare their bodies to give the best possible environment in the womb for the foetus to go through its stages of development. How well do we as services and communities look after pregnant women – if we want long but healthy lives then we have to look after our mothers.
Another thought provoking angle from the programme was the finding that the quality of the eggs that developed in a female foetus whose development was effected by famine was reduced. So the effect of poor maternal nutrition might not just have an impact on one generation but also subsequent generations. Hence our health can be connected not just to what out mothers but also to what our grandmothers ate.