Gut Interactions with Brain and Environment in Children; First International Symposium on Pediatric Neurogastroenterology Capri, Italy, September 18-20, 1997
There is a growing and emerging body of evidence that suggests that nutrition in early life has permanent consequences for long term health and development. Many human fetuses and infants born prematurely have to adapt to a limited supply of nutrients. If this occur at a critical period of growth ie during a period of rapid cell division then nutrition may exert a long lasting of permanent effect on their physiology and metabolism. Lucas has coined the term “programming” for this form of metabolic entrainment (1). Widdowson and McCance (2) showed that even brief periods of undernutrition at a critical period may permanently reduce the numbers of cells in particular organs at such times. For the central and enteric nervous system the critical period of growth is from 25-26 weeks gestation through to 18 months post term. Thus under or malnutrition during this time may “programme” the later performance of both the central and enteric nervous systems.
A number of studies have shown the following general features of programming in the human infant:
- In preterm infants, the period of nutritional sensitivity extends post term and throughout infancy.
- Infants born at full term remain sensitive to nutritional programming through at least the 1 st year of life.
- In infants born small for gestational age at term the adverse long term effects of poor fetal growth may be ameliorated by nutritional management in infancy.
- Specific nutrient status of long chain polyunsaturated fatty acids, Ca, Fe, PO4 and energy may have selective long term programming effects in infancy.
- Non-nutrient factors in human milk may also programme health and developmental outcomes.
Observational studies on both whole milks and specific nutrients have shown effects on the central nervous system. Breast feeding advantages the infant in cognitive and intellectual development compared to infants fed formula milk. In preterm infants there is at least a 10 point advantage by the time they reach the age of 7.5-8 yrs (3). A randomised controlled pilot study of a nutrient enriched formula showed both improved catch up growth and motor development.
Two specific nutrients may have important effects on neurodevelopmental: iron and long chain polyunsatured fatty acids (LC-PUFA).
Iron: there is a large body of data that links iron deficiency during early brain development with long term and possibly permanent neurocognitive deficits (4). These data are reinforced by animal models but long term human studies have been non-randomised and confounded by other variables.
LC-PUFA: n-3 and n-6 series 18-22 C fatty acids are major structural lipids in the central nervous system. Some data show improvement in visual development and in attention and cognitive development when supplemented with LC-PUFA or fed mothers milk (5).
As yet there have been no studies on the enteric nervous system. However there are marked similarities in structure, metabolism and neuronal functioning of two nervous systems. There is a priori no reason why there should not be similary effects as to those described for central psychomotor development. It is quite possible that functional bowel disturbance in childhood could have some of its origins in the adequacy of perinatal nutrition. At the present time this is a totally unexplored field and deserves some attention.
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. John Wiley and Sons, Chichester, 1991; pp 38-55.
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3. Lucas A, Marley R, Cole TJ, Lister G, Leeson-Payne C Breastmilk and subsequent intelligence quotient in children born preterm. Lancet
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4. Loyoff B, Jimeney E, Wolf AB Long term developmental outcome of infants with iron deficiency N. Engl. J Med
1991; 325: 687-694
5. Carlson SE, Werman SH, Rhodes PG, Tolley EA Visual acuity development in healthy preterm infants: effects of marine oil supplementation. Am. J. Clin. Nutrition
1993; 58: 35-42.