A test for serum lipid peroxidation potential has been recently described.1 Serum lipid peroxidation potential is an estimate of the susceptibility of serum lipids to oxidation. It is affected by the balance of circulating prooxidant (such as iron, copper, and high polyunsaturated-to-saturated fatty acid ratios) and antioxidant (such as vitamins E and C, ceruloplasmin, and selenium) factors.1 The balance of these peroxidation factors may, in turn, be affected by health status1,2 and diet.3
Little is known about the peroxidation of serum lipids in healthy, growing infants. Two studies4,5 reported diminished antioxidant activity in cord blood vs adult blood. A study of erythrocyte susceptibility to oxidation, measured as erythrocyte tendency toward hemolysis when lipids in cell membranes are subjected to deliberate oxidation, has shown that erythrocytes of formula-fed infants hemolyze more readily than do erythrocytes of human-milk-fed infants.6
To our knowledge, there are no studies