Optimizing Early Protein Intake for Long-Term Health of Preterm Infants

Abstract

The idea that early protein intake may influence, or program, long-term health in preterm infants is strongly supported by decades of research starting from the early 1980s. At this time, it was recognized that preterm infants required a high protein intake to achieve postnatal growth closer to the intrauterine growth rate of a normal fetus of the same postconceptional age, a goal regarded optimal for short- and long-term health. Subsequently, follow-up of preterm infants randomized to different neonatal diets demonstrated that those receiving higher protein intakes that promoted growth had benefits for brain structure and function up to 16 years later, but also detrimental effects on cardiovascular risk factors such as insulin resistance and adiposity. These effects of early growth on risk of metabolic disease, termed the 'growth acceleration' hypothesis, have been demonstrated in randomized and observational studies in infants born preterm and at term. Nevertheless, on balance, current nutrition policy for preterm infants is based on the consensus that supporting optimal neurodevelopment is the neonatologist's highest priority. Therefore, this policy appropriately favors early administration of a high protein intake to benefit neurodevelopment, irrespective of any increase in cardiovascular risk. The current review will consider the evidence underlying this policy.