Photograph by Vera Kratochvil, License: CC0 Public Domain
Recent research from the University of British Columbia and BC Children’s Hospital Research Institute proved that the amount of physical contact between infants and their caregivers can affect children at the molecular level. The study demonstrated that children who had been more distressed as infants and received less physical contact had an underdeveloped molecular profile for their age. This is the first study to show that the simple act of physical touching on human children can result in deeply-rooted changes in genetic expression.
The researchers measured a biochemical modification called DNA methylation in which parts of the chromosome are tagged with small molecules made of carbon and hydrogen. These molecules act as “dimmer switches” that help control how active each gene is and affect how cells function. The extent of methylation and where on the DNA it takes place can be impacted by external conditions, especially in childhood.
The team analyzed DNA methylation of 94 healthy children with records of received caregiving from the age of five weeks to four and a half years. The DNA methylation patterns the scientists gathered presented consistent differences between high-contact and low-contact children at five specific DNA sites. Two of the five sites are related to genes: one involves in the immune system, and the other in metabolism. The children who experienced higher distress and received little contact had a lower “epigenetic age” than what’s expected from their age. Such low epigenetic age is conceived as an underdevelopment of the child’s molecular profile. As medical genetics professor Michael Kobor said, “In children, we think slower epigenetic aging might indicate an inability to thrive.”
The researchers intend to further examine whether the “biological immaturity” – epigenetic changes resulted from low physical contact – carries broader implications for children’s health, especially their psychological development. According to the lead author Sarah Moore, “If further research confirms this initial finding, it will underscore the importance of providing physical contact, especially for distressed infants.”