The debate over whether breast is best has been ongoing for decades, but recent research suggests that longer or exclusive breastfeeding might be linked to fewer developmental delays and better language or social neurodevelopmental outcomes.
The cohort study involved 570 532 children in Israel, where researchers found that longer and exclusive breastfeeding were independently linked to lower odds of developmental delays after adjusting for key confounders.
The World Health Organisation (WHO) recommends exclusive breastfeeding for the first six months of a baby’s life, followed by continued breastfeeding alongside complementary foods for at least two years.
The researchers analysed data from children born between January 2014 and December 2020, who were born after at least 35 weeks of gestation without severe morbidity and had at least one follow-up surveillance visit at two to three years of age.
In JAMA Network, they report that among 37 704 sibling pairs, they found that children who were breastfed for at least six months were less likely to experience delays in milestone attainment or neurodevelopmental deficiencies than their siblings who were breastfed for less than six months or not at all.
Newsweek spoke to study author Dr Inbal Goldshtein, who was surprised that the link remained strong across different types of analysis.
“The relationship with breastfeeding duration was non-linear, with gradually reduced rates of language-social delays during the first eight months of breastfeeding and diminishing marginal association afterwards,” Goldshtein said.
Breastfeeding and weaning specialist and blogger Danielle Facey, who heads up the The Breastfeeding Mentor, told Newsweek that breastfeeding is crucial for cognitive and developmental growth because of the nutrients in the milk and the physiological processes it supports.
“One key aspect is myelination – the process by which nerve fibres are coated with a protective sheath (myelin), allowing electrical impulses to travel more efficiently in the brain,” she said.
Breast milk also contains long-chain polyunsaturated fatty acids, including DHA and AA, which are essential for building neural tissue and supporting brain growth, Facey added.
Goldshtein said the current data couldn’t differentiate between breastfeeding and pumped milk feeding. “Future research could investigate human-milk feeding vs parent-child bonding, to refine the roles of biological and psychosocial mechanisms behind the observed association,” she said.
Facey said a common misconception was that breastfeeding can prevent fathers from bonding with their baby.
“This simply isn’t true. Fathers and non-birthing parents can bond through skin-to-skin contact, cuddling, baby-wearing, bathing, and feeding expressed breast milk from a bottle,” she said.
“From around six months, or earlier if parents choose to introduce expressed milk, other caregivers can actively participate in feeding. Breastfeeding is just one piece of a nurturing family dynamic, not a barrier to connection.”
Study details
Breastfeeding Duration and Child Development
Inbal Goldshtein, Yair Sadaka, Guy Amit, et al.
Published in JAMA Network on 24 March 2025
Abstract
Importance
Detecting and addressing potentially modifiable factors associated with healthy development is key to optimising a child’s potential. When investigating the outcomes of child development, it is important to account for disparities in feeding practices and avoid confounding bias.
Objectives
To estimate the independent association between breastfeeding and attainment of developmental milestones or neurodevelopmental conditions.
Design, Setting, and Participants
This retrospective cohort study used data from a national network for routine child development surveillance in Israel linked with national social insurance financial entitlements for neurodevelopmental deficiencies. Participants were children born between January 2014 and December 2020 after at least 35 weeks’ gestation without severe morbidity and with at least one follow-up surveillance visit at two to three years of age. Outcome data were collected in March 2023.
Exposures
Duration and exclusivity of breastfeeding in infancy.
Main Outcomes and Measures
The primary outcomes were delays in attainment of developmental milestones and diagnosis of prespecified neurodevelopmental conditions. Multivariable regression, matching, and within-family analyses were used to estimate adjusted odds ratios (AORs) after accounting for potential confounding factors related to the child (gestational age, birth weight, multiple gestation, and child order in the family) and mother (age, socioeconomic status, educational level, marital status, employment, nationality, and postpartum depression).
Results
Of 570 532 children (291 953 [51.2%] male), 20 642 (3.6%) were preterm, 38 499 (6.7%) were small for gestational age, and 297 571 (52.1%) were breastfed for at least 6 months (123 984 [41.7%] were exclusively breastfed). Children who were breastfed for at least 6 months exhibited fewer delays in attaining language and social or motor developmental milestones compared with children exposed to less than 6 months of breastfeeding (AOR, 0.73 [95% CI, 0.71-0.76] for exclusive breastfeeding; AOR, 0.86 [95% CI, 0.83-0.88] for nonexclusive breastfeeding). Among 37 704 sibling pairs, children who were breastfed for at least six months were less likely to demonstrate milestone attainment delays (OR, 0.91 [95% CI, 0.86-0.97]) or be diagnosed with neurodevelopmental conditions (OR, 0.73 [95% CI, 0.66-0.82]) compared with their sibling with less than 6 months of breastfeeding or no breastfeeding.
Conclusions and Relevance
In this cohort study, exclusive or longer duration of breastfeeding was associated with reduced odds of developmental delays and language or social neurodevelopmental conditions. These findings may guide parents, caregivers, and public health initiatives in promoting early child development.
JAMA Network article – Breastfeeding Duration and Child Development (Open access)
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