Breastfeeding and Bottle-Feeding: Implications for Infant Neurodevelopment
The Ongoing Debate
The relationship between breastfeeding, bottle-feeding, and infants’ neurodevelopment remains a significant topic of discussion. Researchers often examine various aspects of infant development, including intelligence levels, speech, and head circumference, in relation to feeding methods.
Breastfeeding Duration and Handedness
A pertinent question arises: Does the duration of breastfeeding influence whether an infant develops right or left-handedness? A study published in the journal *Laterality: Asymmetries of Body, Brain and Cognition* delves into this issue by analyzing data from earlier surveys on breastfeeding practices.
Study Overview
The study assessed seven surveys for potential bias, participant data, and conducted an individual participant data (IPD) meta-analysis. A total of approximately 60,000 mother-infant pairs were included from these previous studies.
Key Findings
The research indicates a possible correlation between bottle-feeding and left-handedness. Specifically, it was found that breastfeeding for less than one month was associated with a 9% lower prevalence of left-handedness compared to bottle-feeding. The rates improved with longer breastfeeding durations: a 15% decrease was observed for one to six months of breastfeeding, while breastfeeding for more than six months yielded a 22% decrease. However, breastfeeding beyond nine months did not show any additional decrease in left-handedness prevalence.
Implications of the Findings
It is essential to clarify that these findings do not imply that breastfeeding directly causes right-handedness. Rather, the duration of breastfeeding may significantly influence an infant’s brain lateralization, particularly during the crucial first nine months of life.
Factors Influencing Handedness
The authors of the study emphasize that handedness may not solely be linked to nutritional factors. Instead, the nurturing aspect of mother-infant bonding could play a more significant role in determining handedness. Additionally, genetics also contributes to this trait.
Future Research Directions
To further explore the associations between breastfeeding, bottle-feeding, and handedness, larger randomized studies involving approximately one million women are recommended.
References
Hujoel, Philippe P. “Breastfeeding and Handedness: A Systematic Review and Meta-Analysis of Individual Participants Data.” *Laterality: Asymmetries of Body, Brain and Cognition.* 2019. 1-19. Online.
Long-term breastfeeding sheds light on whether an infant becomes right- or left-handed. 2019, https://www.eurekalert.org/pub_releases/2019-01/uow-lbs010719.php, assessed 17 Jan. 2019.