Babies who are cuddled more develop a positive variation at the molecular level, leading to a change in gene functioning and affecting the infants' expression for good in the future, according to a 2017 study by researchers from the University of British Columbia in Canada. It revealed for the first time that touching and cuddling a baby affects the epigenome -- the biochemical changes that influence gene expression in the body.
The finding was similar to another study in Jan 2017 that traced similar bonding between mother and child among the kangaroo animals. Published in the journal Paediatrics, it suggested that babies who received more skin-to-skin contact showed better neurodevelopment, a reduction in hyperactivity, higher IQ, less likely to miss school, and even received higher wages as adults than those who did not receive skin-to-skin contact when infants.
The study on cuddling published in Development and Psychopathology asked parents of 94 babies to keep diaries of their touching and cuddling habits from five weeks after birth, and log sleeping, crying, as well as eating behaviour of the infants to find that epigenetic mechanism, in which some parts of the chromosome are tagged with small carbon and hydrogen molecules, changed functioning of the genes, making babies with less physical contact more distressed at a young age.
DNA swabs of the kids, taken four-and-a-half years later, analysed a biochemical modification called DNA methylation, researchers said. The study found that DNA methylation difference between "high-contact" and "low-contact" children at five specific DNA sites, two of which were within genes -- one related to the immune system, and other to the metabolic system, acted as a marker for normal biological development and could be influenced by external and environmental factors. The researchers, however, could not isolate exactly what caused the change.
They also found the epigenetic age, the biological ageing of blood and tissue, marker was lower than expected in kids who did not have much contact as babies as compared with their actual age. "In children, we think slower epigenetic ageing could reflect less favourable developmental progress," said lead researcher Michael Kobor.
The researcher said a further study with wider participation was needed to determine how touching exactly affected epigenetics of babies, but it was established through their study that close contact and cuddles were somehow responsible for a change in the body at a genetic level. "We will follow up on whether the 'biological immaturity' seen in these children carries broad implications for their health, especially their psychological development," another researcher Sarah Moore added.
Another study published in journal Paediatrics suggested babies who received more skin-to-skin contact showed better neurodevelopment, a reduction in hyperactivity, had higher IQs, were less likely to miss school, and even received higher wages as adults than those who did not receive skin-to-skin contact when infants.