The results do not necessarily mean fatty acids in formula have no benefit. However, they suggest the fats do not give children the thinking and language advantage that has been tied to breastfeeding.

Researchers explain in their study, published in the journal Pediatrics, that infants raised on breast milk tend to score higher on tests of mental development than those who are fed formula.

One reason for the gap could be the higher levels of fatty acids found in breast milk, given that the fats are essential for babies' brain development.

"The differences in cognitive development between breastfed and formula-fed infants were a substantial motivating factor in adding (fatty acids) to infant formulas," according to the report.

Most baby formula is cow's milk-based and fortified with fatty acids and other nutrients. 

Formula supplemented with two fatty acids, docosahexaenoic acid (DHA) and arachidonic acid (AA), has been available in the U.S. since 2002.

Although fatty acids are important for brain development, it is not clear adding them to infants' diets will improve their mental skills.

Studies on the issue have had mixed results, so the researchers, led by Dr. Ahmad Qawasmi at Yale University in New Haven, Conn., and Al-Quds University in Jerusalem, sought to get a better verdict by combining them into one analysis.

They used data from 12 trials that compared babies fed formula with fatty acid supplementation to babies fed formula without the extra fats. In total, about 1,800 infants took part in the studies, which were conducted between 1998 and 2005.

The children started drinking formula by one month of age, and around the time they turned one, they underwent exams to measure their motor skills, language abilities and mental development.

Just two of the studies included in the analysis found that babies fed supplemented formula performed better on the tests.

A third report showed a fatty acid-linked boost on some developmental measures but not others, and the remaining nine studies found no cognitive benefits in the babies getting added fatty acids.

Taken together, the studies show the extra fats provide no advantage as far as braininess goes, the researchers said. However, it is still possible that adding fatty acids to formula could benefit infants in other ways, such as with a boost in eyesight or immune function, they noted.

"There also remains the possibility that (fatty acids) could impact later cognitive development or more specific aspects of cognitive development such as attention, information processing, mood, or behavior."

Public health organizations and medical societies consider breast milk to be the best food source for babies.

The American Academy of Pediatrics recommends women breastfeed exclusively for six months, followed by at least another six months of nursing while solid foods are introduced.

 From the May 31, 2012, Prepared Foods’ Daily News