After researchers studied family background, the relationship between breastfeeding and adolescents’ cognition has emerged.

In Chinese youth, long-term breastfeeding showed no clear cognitive associations until researchers accounted for socioeconomic disadvantage, revealing modest gains in math and word recognition, highlighting how family context can shape findings of child development.

Study: Breastfeeding duration and cognitive performance in youth. Image Credit: Asian Photo/Shutterstock

In a recent study published in jama network openA group of researchers examined whether breastfeeding duration is associated with cognitive performance among adolescents, while taking into account socio-economic factors.

Breastfeeding duration and cognitive performance Background

Does prolonged breastfeeding really make babies smarter, or are family circumstances the real driver? World Health Organization (Who) recommends breastfeeding as the best source of nutrition for infants and recommends exclusive breastfeeding for the first 6 months, followed by continued breastfeeding for at least 2 years, but the evidence on whether breastfeeding has long-term cognitive benefits is inconsistent.

The main challenge is socioeconomic status (Session), which strongly shapes both food practices and the learning environment. In many countries, wealthier families breastfeed for longer periods of time, making it difficult to isolate the true biological effects. Conversely, in some populations, the opposite trend exists.

Understanding how breastfeeding duration is associated with child cognitive development in different settings will provide a basis for developing appropriate health and education policies.

More research is needed to provide clarity on the causal relationship between breastfeeding and cognition.

Breastfeeding and Youth Cognition Study Design

This cross-sectional study used data from the China Family Panel Studies (CFPS), a nationally representative longitudinal survey conducted by the Institute of Social Science Survey at Peking University. The study involved youth aged 10–15 who participated in waves of data collection in 2010, 2014 or 2018 and who were born between 1995–2009. Institutional ethics approval for the study was obtained from Peking University Biomedical Ethics Review Committee, and informed consent was collected.

Breastfeeding duration was assessed retrospectively from caregivers’ reports and classified as less than or equal to 6 months or more than 6 months according to WHO recommendations. This measure included any breastfeeding, including exclusive and mixed feeding. Standard tests of cognitive performance, including mathematics and word recognition tests based on the school curriculum, were completed. Standardized scores were used, and all scores were converted to age-adjusted z-scores to control for differences in developmental level. Poor cognitive performance was defined by a score at or below the 15th percentile.

Covariates included child characteristics (sex, ethnicity, gestational age, birth order, birth year), parental factors (age at birth, educational level), and household indicators (residence, income, cooking fuel type). Survey-weighted generalized linear models were used to estimate associations. Three models were applied: unadjusted, non-Session adjusted, and completely Session-Well Adjust. Sensitivity analyzes including adjustment for parental perception and birth weight were conducted to ensure robustness.

Socioeconomic Adjustment and Cognitive Conclusions

The final sample consisted of 5,436 youth with an average age of 12.03 years, of whom 52.5% were male. Of those, 13.8% were breastfed for 6 months or less, while 86.2% were breastfed for a long time. It was observed that prolonged breastfeeding is more common in families with younger SessionThese include lower parental education and household income, and these children were also more likely to live in rural areas and use unclean cooking fuels, reflecting wider environmental harms.

Time trends showed an overall decline in breastfeeding duration across birth cohorts from 1995 to 2009. However, despite the reduction in total duration, prolonged breastfeeding remained more prevalent among parents from low-income households and those with less education. This pattern of association differs from the pattern observed in many high-income countries, where higher Session Usually associated with longer duration of breastfeeding.

In unadjusted analyses, cognitive function was not significantly associated with how long the child was breastfed. In this study, children who were breastfed for more than six months had slightly higher, non-significant point estimates for math tests (β = 0.03; 95% confidence interval (CI), −0.06 to 0.13) and slightly lower, non-significant point estimates for word recognition tests (β = −0.02; 95% CI−0.13 to 0.09) compared to those who were breastfed for six months or less. However, after adjusting for non-Session covalent, then for SessionProjections became positive, and completely Session-adjusted models, they were statistically significant. Children who were breastfed for more than six months had significantly better math scores (β = 0.14; 95%) CI0.05 to 0.22) and word recognition score (β = 0.12; 95% CI0.02 to 0.21).

Completely Session-Adjusted analysis of binary outcomes reduced the odds of poor math performance by 35% (odds ratio)Or), 0.65; 95% CIfrom 0.48 to 0.88) and a 36% reduction in the probability of poor word recognition performance (Or0.64; 95% CI0.47 to 0.87) is associated with prolonged breastfeeding. This study provides evidence that breastfeeding duration is associated with small improvements in cognitive ability, even after controlling for Session.

Nonlinear analysis using restricted cubic splines showed that the lowest probability of poor performance occurs around 6 to 12 months of breastfeeding, with attenuation over longer periods. This suggests that the association may not be strictly linear, but does not establish an optimal breastfeeding duration, and may reflect the timing of infant growth, changes in milk composition, or the introduction and quality of complementary feeding during this period.

Sensitivity analyzes supported the robustness of these findings across different analytical specifications, adjustments, and analyses. These findings also highlight how an individual’s socio-economic context may enhance or obscure engagement with breastfeeding.

Breastfeeding policy and research implications

In this cross-sectional analysis, breastfeeding duration was not associated with cognitive performance in unadjusted models, but showed a positive association after accounting. Session. Long-term breastfeeding was more common in lower socio-economic groups, which initially obscured its association with cognitive outcomes. After adjustment, modest improvements in mathematics and word recognition were observed, along with a reduced likelihood of poor performance.

These results indicate that breastfeeding may be associated with adolescent cognitive development, although causality cannot be inferred. Providing support through policy as well as reducing breastfeeding Session disparities may help improve child development opportunities, but further longitudinal research is needed.