Effect of Breastfeeding in Early Life on Cardiorespiratory and Physical Fitness: A Systematic Review and Meta-Analysis

Background: Numerous studies have reported the associations between the type of feeding during infancy and subsequent chronic diseases.

Objective: The objective of this systematic review is to synthesize the available literature concerning the effect of breastfeeding in infancy on physical and cardiorespiratory fitness in children and adolescents.

Materials And Methods: We performed a comprehensive search of medical bibliographic databases to identify observational studies reporting the association between breastfeeding and cardiorespiratory or physical fitness. Random effects model was used for calculating the pooled estimates.

Results: Three studies with 2,792 children were included in the meta-analysis. The mean value of VOmax was similar between formula-fed and 1-3 months breastfed participants (standardized mean difference [SMD]: 0.1, 95% confidence intervals [CI]: -0.09 to 0.29, p = 0.31). There was no difference between 3 and 6 months breastfed (SMD: 0.17, 95% CI: -0.01 to 0.35, p = 0.06), >6 months breastfed (SMD: 0.37, 95% CI: -0.03 to 0.78, p = 0.07), and formula-fed children. The pooled SMD in handgrip strength was 0.09 (95% CI: -0.04 to 0.23; p = 0.17) between 1 and 3 months breastfed and formula-fed children .Nevertheless, 3-6 months (SMD: 0.13; 95% CI: 0.03-0.24) and >6 months (SMD: 0.19; 95% CI: 0.01-0.37) breastfeeding was associated with higher handgrip strength compared with formula-fed children. Breastfeeding for 1-3 (SMD: 0.20; 95% CI: 0.12-0.28), 3-6 (SMD: 0.27; 95% CI: 0.18-0.37), and >6 months (SMD: 0.34; 95% CI: 0.11-0.58) led to a significantly higher standing long-jump performance compared with formula feeding.

Conclusions: Breastfeeding shows beneficial effects on physical fitness, but further well-designed studies need to clarify effects of breastfeeding on cardiorespiratory fitness.