The expression of certain genes in umbilical cord blood is associated with an increased risk of childhood obesity. The finding suggests that cord blood could predict whether a newborn will develop obesity, allowing doctors to intervene sooner.
Environmental factors such as pollution, diet and exercise can influence the activity of genes by switching them on or off with chemical tags called epigenetic marks. These changes can increase the likelihood of developing various health conditions, including obesity.
To understand how epigenetic changes during pregnancy relate to childhood obesity, at Harvard University and her colleagues analysed data on 831 newborns in the Boston Birth Cohort. This study tracked changes in the infants鈥� body mass index (BMI) from birth until 18 years of age, and collected blood from their umbilical cords for epigenetic analysis. Of the participants, most were from low-income, urban areas and more than 72 per cent were Black.
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The researchers compared the umbilical cord blood of participants who developed obesity before turning 18 with that of those who didn鈥檛. They found significant associations between childhood obesity and epigenetic marks on three genes, one of which occurred on a gene important for producing inflammation.
Previous research has shown that people with obesity have high levels of inflammation, which, in turn, helps drive the development of other diseases, like type 2 diabetes.
This finding suggests that children with obesity may be predisposed to heightened inflammation from birth, says at Northwell Health in New York, who was not involved in the study.
Additionally, these results suggest that epigenetic analysis of umbilical cord blood could identify infants at a high risk of obesity. 鈥淲e cannot perform [epigenetic analysis] for every newborn because the technology is very expensive, but these types of studies provide evidence that we may be able to have early-life predictors of long-term obesity,鈥� says Meir, who presented the findings at a conference of the American Society for Nutrition in Boston on 23 July. 鈥淪omeday, when the technology becomes more affordable, this could be one of those screenings.鈥�
Such a screening could guide paediatric counselling, says Hes. For instance, if the test is positive, doctors may place a greater emphasis on breastfeeding, which has been shown to protect against childhood obesity, she says.
However, these findings must be validated in larger cohorts, says Meir. This is especially important given most infants in this study were Black, says Hes. 鈥淵ou really can鈥檛 generalise that to the whole population,鈥� she says.
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