Breastfeeding is associated to mitochondrial DNA content of adolescents

Abstract

TPS 771: Diet and lifestyle, Exhibition Hall, Ground floor, August 26, 2019, 3:00 PM - 4:30 PM Background/Aim: Several studies emphasized the benefits of breastfeeding on the child’s health, including improvement of the development of the immune system, brain and cognitive function. We hypothesized that besides these beneficial effects, breastfeeding is also associated with mitochondrial DNA (mtDNA) content at adolescent age. Methods: This study was part of the third cycle of the Flemish Environment and Health study (FLEHS III) cohort and included 306 adolescents aged 14-15 years. DNA was extracted from peripheral blood and the relative mtDNA content was determined using quantitative PCR. Data on breastfeeding was retrieved by a questionnaire filled out by the mother. Multiple linear regression models, adjusted for important confounding variables, were used to associate breastfeeding and mtDNA content in adolescents. Results: Breastfeeding was positively associated with mtDNA content. mtDNA content was 23.1% (95% CI 4.6-44.9; p = 0.013) higher in breastfed adolescents. When infants were breastfed for 1-10 weeks, 11-20 weeks, and over 20 weeks, mtDNA content was increased with 15.1% (95% CI -7.6-43.6; p = 0.208), 23.9% (95% CI 1.4-51.3; p = 0.036), and 31.7% (95% CI 4.7-65.5; p = 0.019), respectively. In sensitivity analyses, we observed that breastfeeding is independently associated to mtDNA content in non-smoking adolescents and that the association was stronger in boys than in girls. Conclusions: In addition to the well-known long-term effects of breastfeeding, this study shows a positive association between breastfeeding and mtDNA content in adolescents. mtDNA content gradually increased with longer periods of breastfeeding. An increase in mtDNA may be an underlying mechanism of the beneficial effects of breastfeeding.