Editorial

Premature birth is associated with a number of adverse sequaelae; these include bronchopulmonary dysplasia, necrotizing enterocolitis, intracerebral haemorrhage and retinopathy of prematurity. It has been suggested that these conditions are the outcome of “oxygen radical disease” [1] and occur as a result of oxidative injury. Premature infants often require high inspired supplemental oxygen concentrations because of lung disease and severe sepsis. These conditions are associated with reduced cardiac output and hypotension, which may lead to hypoxemia of the tissues. This can result in the generation of oxygen derived free radicals (reactive oxygen species (ROS)). To defend against the actions of ROS, there are antioxidants such as ascorbic acid (vitamin C) and tocopherol (Vitamin E) and enzymatic defenses such as super oxide dismutase (SOD), glutathionine peroxidase and catalase. Unfortunately, the premature infant has poor antioxidant defense mechanisms. In this issue of the journal Tsopmo and Friel [2] report data from a literature review to highlight that human milk has antioxidant properties. In particular, they note that human milk contains vitamins C and E and enzymes including superoxide dismutase, catalase and glutathione peroxidase. Human milk is often frozen and stored for deferred use for very prematurely born and sick infants. Freezing decreases the antioxidant activity of milk in a time dependent fashion [3], but the antioxidant activity of human milk, despite storage, is still higher than that of infant formulae. This may at least partially explain why prematurely born infants fed with breast milk rather than cow's milk based infant formulae have a lower incidence of nectrotising enterocolitis [4] and retinopathy of prematurity [5]. REFERENCES [1] Saugstadt OD. Oxygen toxicity in the neonatal period. Acta Pediatr Scand 1990; 79: 881-92. [2] Tsopmo A, Friel JK. Human milk has anti-oxidant properties to protect premature infants. Curr Ped Rev 2007; 3: 47-54. [3] Hanna N, Ahmed K, Anwar M, Petrova A, Hiatt M, Hegyi T. Effect of storage on breast milk antioxidant activity. Arch Dis Child Fetal Neonatal Ed 2004; 89: F518-20. [4] Lucas A, Cole TJ. Breast milk and necrotizing enterocolitis. Lancet 1990; 336: 1519-23. [5] Cunningham AS. Breast feeding, antioxidants and the retinopathy of prematurity. Am J Obstet Gynecol 1987; 156: 1040-1.