In the first of its kind, new research conducted by the University of British Columbia and British Columbia Children's Hospital Research Institute shows that DNA methylation patterns in children can be altered based on the amount of physical contact received from caregivers during infancy, with effects still evident at four and a half years of age. The study aimed to expand on animal models of early postnatal interactions between mother and infant, which highlighted the importance of tactile contact for biobehavioural outcomes.
Parents of five-week-old babies were asked to track the amount of physical contact from caregivers, as well as their infant's behaviour, to assess the impact of normative variation in contact on DNA methylation. Using a daily diary, filled in by the caregivers, variations in infant contact were assessed to determine the effect on genetic expression. The study focused on the glucocorticoid receptor gene and nuclear receptor gene, along with two candidate genes related to the neurobiology of social bonds and postnatal plasticity.
DNA methylation levels were compared across the low and high contact groups, with no differences found at candidate genes related to the neurobiological encoding of tactile contact. There was, however, an association made between infant distress levels and epigenetic age deviation in infants who had experienced lower levels of contact. This indicates that epigenetic age deceleration is occurring, which may cause delays in maturation as a result of increased stress levels.
Children who had received less physical contact and who were more distressed as infants subsequently had an underdeveloped molecular profile in their cells when assessed at four and a half years of age, suggesting they were biologically lagging.
The results from this study show that biological immaturity results from higher levels of distress and lower amounts of contact. However, the long-term effects of these epigenetic changes for the health and development of the child are still unknown. The research team aims to conduct a further longitudinal study to determine whether a low epigenetic age carries broader implications for a child's physical and psychological health.
For practitioners, this research provides an important correlation between early postnatal contact and normative social and cognitive development, and suggests clinically important outcomes in the health of children as well as the formation of strong social bonds.
- Moore SR, McEwen LM, Quirt J, et al. Epigenetic correlates of neonatal contact in humans. Development and Psychopathol 2017;29(5):1517-1538 [Abstract]