Breastfeeding is wonderful for developing the bond between mother and baby, helping new mothers lose the baby weight, and boosting an infant’s immunity to illnesses. But don’t count on it to raise a baby’s IQ, a new study suggests.

New research published in the journal Pediatrics indicates that infants who are breastfed do not have better cognitive skills by the time of kindergarten than those who weren’t breastfed.

Several studies over the years have found that breastfed children score better on intelligence tests than others, but this new research questions that, by trying to take into account some of the reasons that certain mothers breastfeed and others do not.

The study followed more roughly 8,000 Irish children from age nine months to five years. The mothers reported if they breastfed their children and for how long. They then filled out questionnaires about their children’s problem behaviours, expressive vocabulary, and cognitive abilities at the ages of 3 and 5 years. Standardized tests were also used to assess the childrens’ skills and teachers’ reports on their behaviours were included too.

At first, breastfeeding was associated with better development on almost every outcome. But then the researchers applied a statistical analysis technique called “propensity score matching,” which attempts to account for the factors that determine whether mothers choose to breastfeed. For example, several studies have shown that women of lower socioeconomic status are less likely to breastfeed than those of higher status.

After applying the scoring method, the researchers found no statistically significant gains at age five for the kids who had breastfed compared to those who had not.

The study authors say their findings suggest “that the earlier observed benefit from breastfeeding may not be maintained once children enter school.”

However, the authors did note that children who were fully breastfed for six months or longer had lower parent-rated scores for hyperactivity at age three.

Still, while the study questions the cognitive benefits of breast milk, there are plenty of other benefits of “baby’s first food,” says Toronto-area lactation consultant Teresa Cozzella.

“Studies do show that there is decreased risk of ear infection, gastrointestinal infection, a decreased risk of SIDS, so different benefits,” she tells CTV Toronto.

The World Health Organization also notes that breastfeeding reduces the risk of ovarian cancer and breast cancer for mothers, is readily available and affordable, provides essential antibodies to babies and helps reduce the risk of infant mortality through diarrhea or pneumonia.

Health Canada advises new moms to breastfeed exclusively for the first six months and to continue nursing along with feeding other foods for the first two years of a child's life.

Toronto area physician Dr. Rhea Uy is currently breastfeeding her baby, Hunter, and says beyond the health benefits, there are other reasons to nurse, particularly to forge a good connection between mother and child. But she says mothers who can’t breastfeed for whatever reason should not worry they are depriving their children.

“It's still a personal decision and I still recommend (breastfeeding), but don't beat yourself up if you can’t,” she says.

With a report from CTV Toronto’s Pauline Chan