Breast milk may be best, but there is more evidence that women who can't breastfeed can give their babies a boost by feeding them formulas fortified with the omega-3 fatty acids.
The baby formulas, which contain the fatty acids DHA and ARA, have been available in the United States for a little more than a year.
In one new study, full-term infants (those born after 37 weeks of pregnancy) who were fed a fortified baby formula showed clear benefits in terms of visual development compared with infants fed nonfortified formula. In another, preterm infants gained weight faster and showed enhanced brain development when fed fortified formulas.
Neither study compared fortified baby formulas with breast milk, however, although one did use breastfed babies as a reference group. Both were paid for by Mead Johnson Nutritionals, the maker of a best-selling DHA/ARA fortified formula.
"These studies strongly suggest that babies who are entirely formula-fed do better when they are fed supplemented formulas," says Eileen E. Birch, PhD, who led one of the studies. "They developed more like breastfed kids."
The omega fatty acids — DHA (for docosahexaenoic acid) and ARA (for arachidonic acid) — are naturally present in breast milk and have been available in some infant formulas since 2002.
Earlier studies have shown that formula-fed babies fare better in terms of brain development during their first year of life when given fortified formula.
In the first of the newly reported studies, 103 term infants were fed either DHA/ARA-fortified baby formula or formula without the fatty acids during their first year of life. The findings are published in the April issue of the American Journal of Clinical Nutrition.
According to the authors, visual acuity in the DHA/ARA-supplemented babies was "significantly better" during the first year than among the babies fed unsupplemented formula.
A previous study of visual development at 12 months found no such advantage for DHA/ARA supplementation. But Birch tells WebMD that babies in the previous study got lower levels of the two fatty acids.
Babies in Birch's study were fed formula with 0.36% DHA and 0.72% ARA, which she says is similar to the amount that most breastfed infants get. She recommends that parents look for supplemented formulas with the highest levels of the fatty acids.
Algae vs. Fish Oil
The second study, published in the April issue of The Journal of Pediatrics, compared outcomes among preterm infants fed fortified and nonfortified baby formulas.
Half of the fortified-formula infants were given a commercially available formula in which DHA/ARA was derived from a plant source — algae. The others drank formulas with DHA/ARA derived from fish oil.
All of the fortified formulas now on the market used the algae-derived fatty acid.
The babies fed formula with algae-derived fatty acids gained weight quicker than the babies fed formula with fish oil-derived fatty acids up to about age 1. Their growth was found to be similar to that of full-term infants who were breastfed.
Both supplemented formula types were also associated with more rapid brain and motor development.
Though both new studies show benefits for babies fed fortified baby formulas during the first year of life, it is not yet clear if those benefits are still seen in older children. Oregon Health and Sciences University nutrition professor William E. Connor, MD, says there is some evidence that the benefits are long lasting.
"Obviously, we need more studies that follow these children longer," he tells WebMD. "But it does seem that these formulas that mimic the composition of breast milk as closely as possible do benefit children long term."
SOURCES: Birch, E. American Journal of Clinical Nutrition, April 2005; vol 81: pp 871-879. Clandinin, M.T. The Journal of Pediatrics, April 2005; pp 461-467. Eileen E. Birch, PhD, Retina Foundation of the Southwest, Dallas. William E. Connor, MD, professor of clinical nutrition, Oregon Health and Science University.