Reappraisal of linoleic acid requirement of the young infant, with particular regard to use of modified cows' milk formulae.

Most infants in the UK are bottle fed with cows' milk formulae that are alleged to provide less than the minimum requirement for linoleic acid, i.e. 1% of the total dietary energy. 20 term infants fed solely on a modified cows' milk formula that provided 0.55% of the energy from linoleic acid were therefore examined for evidence of deficiency. Rates of growth in length and weight, measured during the first 3 months of life, were identical with those of 20 wholly breast-fed infants. Voluntary food intakes (kcal/kg per day) followed the normal pattern. The fatty acid composition of the plasma lipids showed changes characteristic of a low intake of linoleic acid, but triene:tetraene ratios did not indicate a deficiency state, and clinical signs of deficiency were not observed. These findings suggest that the requirement for linoleic acid is substantially less than was formerly believed. The small amount of alpha-linolenic acid present in cows' milk may however exert a sparing effect on linoleic acid.