Cuddling with your infant may not just make your child feel warm and loved. One study found that closeness may impact babies on the molecular level – and the effects could last for years.
Parents of 94 babies kept diaries of their touching and cuddling habits for the first five weeks of their child’s life. They were also asked to record other behaviors, like when their baby slept and cried.
Four-and-a-half years later, DNA swabs were taken from the kids. These samples were tested for a biochemical modification called DNA methylation. During DNA methylation, some parts of the chromosome are tagged with small carbon and hydrogen molecules. This changes how genes function.
Researchers analyzed the samples and found clear differences in DNA methylation between “high contact” and “low contact” children at five different DNA sites in genes. Two of these sites were related to the metabolic system and the immune system.
They also noticed differences in the biological ageing of blood and tissue. Children who experienced higher distress and received little physical contact had a lower “epigenetic age” – or an estimate of biological age based on changes in DNA – than their counterparts. However, the downstream effects of these epigenetic changes on child development and health aren’t known yet.
“We plan to follow up on whether the ‘biological immaturity’ we saw in these children carries broad implications for their health, especially their psychological development,” said lead author Sarah Moore, a postdoctoral fellow. “If further research confirms this initial finding, it will underscore the importance of providing physical contact, especially for distressed infants.”
The research was published in Development and Psychopathology.