Longer breastfeeding was associated with modest improvements in cognitive performance among Chinese adolescents, but only after researchers accounted for family socioeconomic status, according to an Apr. 27 study published in JAMA Network Open.
The findings matter because previous research on the link between breastfeeding and intelligence has been inconsistent, partly due to differences in family background that can influence both feeding practices and learning environments. The World Health Organization recommends exclusive breastfeeding for the first six months of life and continued breastfeeding for at least two years, but whether this practice directly benefits long-term cognitive development remains unclear.
Researchers used data from the China Family Panel Studies, a large national survey conducted by Peking University. The study included more than 5,400 youths aged 10-15 years who were born between 1995 and 2009. Breastfeeding duration was classified as six months or less versus more than six months based on caregiver reports. Standardized math and word recognition tests were used to assess cognitive function.
Initial analyses showed no significant difference in test scores between children breastfed for longer or shorter periods. However, after adjusting for socioeconomic factors such as parental education and household income—variables that were lower among families who breastfed longer—the association became statistically significant. In fully adjusted models, those breastfed for over six months had higher math (β = 0.14) and word recognition (β = 0.12) scores compared to those breastfed less.
Further analysis revealed a reduction of about one-third in the odds of poor mathematics or word recognition performance among children with extended breastfeeding durations after accounting for socioeconomic differences. Nonlinear analysis suggested the strongest association occurred around six to twelve months of breastfeeding duration.
The authors concluded that while causality cannot be established from this cross-sectional study, supporting both breastfeeding practices and efforts to reduce socioeconomic disparities may help improve developmental outcomes for children.
