By Avigayil Kadesh 

Breastfeeding is proven to promote babies’ physical and mental development in many ways. Can it also protect children against attention deficit/hyperactivity disorder (ADHD), the most commonly diagnosed neurobehavioral disorder in children and adolescents? 

An Israeli study found a clear link between rates of breastfeeding and the likelihood of developing ADHD, even when typical risk factors were taken into consideration.  

Infants who were bottle-fed at three months of age were found to be three times more likely to have ADHD than those who were breastfed during the same period. The study results were published in Breastfeeding Medicine and shared at a recent congress of the Pediatric Academic Societies’ annual meeting in Washington, DC. 

Dr. Aviva Mimouni-Bloch, one of the lead researchers, says the strength of the correlation surprised her because, as head of the Child Neurodevelopmental Center at Ra’anana’s Loewenstein Rehabilitation Hospital, she is well aware of the strong genetic component of ADHD.  

“On the other hand, we must be very careful with the interpretation of these results,” she adds. “In no way can our study say anything about the causality of this association, because maybe these children have a difficult temperament so mothers who intended to breastfeed had to give it up. We can only talk about the association.” 

Another limitation is that the study was retrospective, meaning it required participating parents to recall babies’ breastfeeding history rather than document it in real time.  

“But the differences were significant statistically,” says Mimouni-Bloch. “In the end, we speculated that prevention of ADHD may be added to the list of the known advantages of human milk feeding.” 

Comparing to siblings without ADHD 

The unfunded study was the brainchild of Dr. Anna Kachevanskaya from Beilinson Hospital at Rabin Medical Center in Petah Tikva, who suspected that breastfeeding might protect against ADHD. She approached Mimouni-Bloch, a specialist in child development and pediatric neurology who was at that time diagnosing and treating children with ADHD in the pediatric neurology clinic with Dr. Avinoam Shufer at Schneider Children’s Medical Center.  

“There were no data on any differences [between breastfed and non-breastfed children as concerns ADHD], so we decided together how to conduct this study with [neonatologist] Dr. Nehama Linder from Beilinson,” she says.  

Between 2008 and 2009, the researchers compared breastfeeding histories of children from six to 12 years of age at Schneider, divided into three groups. One group included children diagnosed with ADHD at the hospital, the second included the siblings of the ADHD patients, and the control group included children without neurobehavioral issues. 

“What was unique about our study was the two control groups,” says Mimouni-Bloch. “We added the siblings of children with ADHD because they have a similar genetic background, environment and tendency of the mother to breastfeed.” 

In addition to describing their nursing habits during the first year of their child's life, parents answered a detailed questionnaire on relevant issues such as parental marital status, level of education, problems during pregnancy such as hypertension or diabetes, birth weight of the child and genetic links to ADHD. 

Taking all risk factors into account, they found that children with ADHD were far less likely to be breastfed in their first year of life than the children in the other groups. At three months, only 43 percent of children in the ADHD group were nursed compared to 69% of the sibling group and 73% of the control group. At six months, 29% of the ADHD group was breastfed, compared to 50% of the sibling group and 57% of the control group. 

Is the critical factor milk or mom? 

The numbers are impressive, but the researchers do not know if the protective benefit comes from the milk itself or from the sensory contact with the mother. However, an earlier study cited by the Israeli researchers showed that the intelligence quotient (IQ) of children who were fed human milk by nasogastric tube was eight points higher than that of children fed formula by nasogastric tube. 

“Human milk has some unique fatty acids that have positive benefits. But maybe the sensory experience is as important. We really don’t know,” says Mimouni-Bloch, who also is a lecturer at Tel Aviv University's Sackler Faculty of Medicine.  

“We plan to apply for grants and find more doctors and psychologists to be involved so we can study children from birth and prospectively follow them, taking information at specific points about what they eat, what their temperament is, and if they get human milk through bottle or breast,” Mimouni-Bloch says. 

Her uncle, Dr. Francis Benjamin Mimouni of Dana Dwek Children's Hospital in Tel Aviv, helped with the analysis of the data and co-wrote the article. 

A similar study using different methodology was also presented at the Pediatric Academic Societies’ meeting by Dr. Andrew Adesman of Cohen Children's Medical Center of New York. Among the children in their study, Adesman and his colleagues found that some 54% of the ADHD children were breastfed, compared with 78 percent of the non-ADHD children. Adesman had compared 54 preschool children with ADHD to 54 preschoolers without the disorder, using data drawn from the 2007 National Health Survey. 

Mimouni- Bloch says this second study strengthens the results of her group’s findings.