Babies who are exclusively breastfed for at least three months have different blood markers compared to those who are not breastfed, according to an April 16 study led by the Barcelona Institute for Global Health, the University of Exeter, and the University of Bristol. The research is described as the largest of its kind and was published in Clinical Epigenetics.
The study examined epigenetic marks—chemical changes that affect how genes function—in children's blood samples. Specifically, researchers focused on DNA methylation, a process detectable in blood that can influence gene activity. They found higher levels of DNA methylation on genes related to immunity and development in children who had been exclusively breastfed for at least three months compared to those who had not been breastfed.
The international project included data from 3,421 children across 11 studies in countries such as Spain, the Netherlands, Finland, France, Greece, Lithuania, Germany, South Africa and the United States. In the United Kingdom alone it involved cohorts from Bristol's Children of the 90s study, Born in Bradford study and Isle of Wight Birth Cohort Study. Information about breastfeeding was collected through questionnaires completed after birth while DNA methylation was measured from samples taken when children were aged five to twelve years old.
Dr Mariona Bustamante from ISGlobal said: "Our results are new and interesting, but we do need to interpret them with some caution. Our study is designed to be collaborative and international; however we need to study more diverse groups to fully understand this biology." The researchers noted that their findings do not show whether these epigenetic differences result in changes to immunity or development.
Previous research has linked breastfeeding with short- and long-term health benefits for children. This new work adds evidence suggesting a biological 'memory' may persist years after breastfeeding ends.
The project received funding from several sources including the Medical Research Council (MRC), Wellcome Trust and Horizon 2020.
