Kenneth Glad
New evidence from early childhood health research is drawing attention in Norway. The results show a measurable difference between groups, but leave causation unresolved.
Researchers at the University of Bergen, Norway, have found a modest connection between exclusive breastfeeding in infancy and fewer ADHD symptoms later in childhood.
The study, available through ScienceDirect, focused on ADHD symptoms rather than confirmed diagnoses. Children who were exclusively breastfed for more months generally had lower symptom levels at ages three, five and eight.
The association appeared in both boys and girls. It was strongest for exclusive breastfeeding up to six months, most visible at ages three and five, and smaller by age eight.
ADHD can involve difficulties with attention, impulse control and activity level. Because these traits vary from child to child, large population studies can help identify recurring differences across families.
Family comparisons helped test the result
The team used data from 37,600 families in the Norwegian Mother, Father and Child Cohort Study, known as MoBa. Mothers reported feeding habits six months after birth.
To reduce the risk of misleading results, the researchers adjusted for known genetic ADHD risk and sociodemographic conditions. They also compared siblings within the same families when breastfeeding histories differed.
Sibling comparisons can strengthen this type of analysis because children in the same family share many background factors. Still, they cannot rule out every influence, including pregnancy differences, birth circumstances, infant behavior or parental health.
Berit Skretting Solberg, who led the work, told Norwegian broadcaster NRK that ADHD has a strong hereditary component. She said mothers with ADHD symptoms may breastfeed less often, while babies who later show ADHD symptoms may also be harder to breastfeed.
“This may explain the link between less breastfeeding and more ADHD symptoms in the child,” Solberg said.
Health advice reaches beyond ADHD
The Bergen results build on a larger body of work on breastfeeding, infant health and maternal recovery. They do not make breastfeeding a single explanation for ADHD risk.
Helsenorge (Norway’s official public health portal) recommends exclusive breastfeeding for the first six months, followed by continued breastfeeding through the first year or longer when it works well for mother and child.
They say that breast milk gives infants nutrition and immune protection while their own immune systems are still developing. It may help protect against stomach illness, ear infections and respiratory infections, and may also reduce later risks of overweight and diabetes.
For mothers, breastfeeding helps the uterus contract after birth. Helsenorge also links it to lower long-term risk of breast cancer, ovarian cancer and type 2 diabetes.
For now, the conclusion remains limited: In a large Norwegian sample, longer exclusive breastfeeding coincided with fewer reported ADHD symptoms. The work supports further study, but does not prove that breastfeeding prevents ADHD.
Sources: NRK, University of Bergen, ScienceDirect, Helsenorge
