Lesson 2: Benefits of Optimal Preterm Nutrition in the Neonatal Intensive Care Unit (NICU)
2.5 Effects of Nutrition on Brain Development
Nutrient deficits can affect both anatomic development and functioning of the preterm infant's brain. For example, growth factors, which function to direct the growth and development of the brain, may not be produced normally if certain nutrients are lacking. Neuronal development may be hampered by a nutrient deficit, resulting in fewer or less differentiated neurons and altered neuronal function. Myelination, nutrient delivery and neuronal trafficking may not occur normally if nutrient deficiencies affect the development of different types of glial cells. The brain's neurochemical functioning can likewise be impaired if nutrient deficits result in lower concentrations of neurotransmitters and numbers of receptors at the synapses (Ramel & Georgieff 2014).
Nutrients particularly important for normal anatomic development of the brain include protein, carbohydrates, iron, zinc and long-chain polyunsaturated fatty acids (LC-PUFA). Nutrients affecting neuronal and synaptic function include glucose, protein, iron, zinc, LC-PUFAs and zinc (Ramel & Georgieff 2014). Carbohydrates, especially glucose, are the primary fuel for the development and homeostasis of the brain. Fats are clearly important since they comprise a large component of the structure of the brain (e.g. myelin synthesis, synaptosome formation, cell membrane). Proteins are not only important as building blocks of the structure of the brain but also as growth factors and neurotransmitters. Iron has been shown to be critical for normal development of fetal and neonatal brain. Zinc regulates neurotransmission in the hippocampus, the nutrient is also necessary for DNA, RNA and protein synthesis throughout the brain. Choline participates in neurotransmitter synthesis (acetylcholine) and myelin synthesis (phosphotidylcholine) is an important nutrient in the development of the brain.
Figure 9: Nutrients regulate brain anatomy and physiology.
Source: ENeA own;
Areas and structures of the brain that are highly metabolically active and thus especially prone to damage from nutritional deficits during the period following preterm birth are the hippocampus, the cerebellum and myelin, important for memory and learning, balance and coordination and neuronal processing speed, respectively (Ramel & Georgieff 2014).
The current recommended intake of nutrients to support brain development of the preterm infant is covered in Unit 2 of this Module.
