Researchers in the United Kingdom followed 262 children from birth until four to six years of age. Seventy-eight of the children were breast-fed, while 184 were formula-fed.
Because scientists have previously hypothesized that chemical known as docosahexaenoic acid (DHA) — found in higher concentrations in breast milk than in formula — enhances the vision of developing children, the researchers randomly added DHA to the formulas of some of the non-breast-fed children.
DHA is an omega-3 fatty acid that is added to many brands of infant formula, which are then marketed as being "closer" to breast milk. Some studies have suggested that children who consume formulas fortified with DHA have higher cognitive function than children who drink unfortified formula. However, these studies have not compared DHA-fortified formulas to breast milk itself.
The study found that the breast-fed children were significantly more likely to score higher on tests of stereo-acuity (depth perception) than the formula-fed ones. There was no significant difference in stereo-acuity between the formula-fed children who had received the DHA supplement and those who had not.
"Breastfeeding is absolutely essential for providing healthy nutrition to newborns," said consumer health advocate Mike Adams, author of "The Seven Laws of Nutrition."
"For decades, infant formula manufacturers have tried to convince mothers that their breast milk is nutritionally inferior to infant formula, but this is all just marketing propaganda designed to sell products at the expense of infant health. Breast milk always has been, and always will be, the best nutrition for infants."
Previous studies have linked consumption of infant formula to a higher risk of asthma, eczema and insulin-dependent diabetes, as well as higher rates of respiratory, intestinal, middle-ear and other bacterial infections. Breast-fed children have also been shown to have better cognitive development than their formula-fed peers.