Risk of obesity influenced by changes in our genes

27 April 2017

Children’s risk of obesity as they grow up can be influenced by modifications to their DNA prior to birth, a new study has found.

The revelation comes from researchers at the University of Southampton with the Epigen Global Consortium who analysed epigenetic modifications to DNA in the umbilical cord tissue of babies.

Epigenetic modifications control the activity of our genes without changing the actual DNA sequence.

One of the main epigenetic modifications is DNA methylation, which plays a key role in an embryo’s development and the formation of different cell types and helps to regulate when and where genes are switched on. 

DNA methylation was originally thought to be a very stable modification which once established was then maintained throughout the life span of an individual.

But this latest research contributes to growing evidence that the level of DNA methylation can be affected by a range of environmental factors, such as parental health, diet and lifestyle.

The University of Southampton researchers compared DNA methylation levels present at birth with the amount of fat tissue in children at ages four and six.

They found that lower DNA methylation at the CDKN2A gene, which regulates the production of fat cells, was associated with a greater risk of the child developing obesity in later life.   

Analysis showed that a 10 per cent decrease in methylation at the CDKN2A gene was associated with an increase in fat mass of around 220g at age four years.

Lead author Karen Lillycrop says the new research could help scientists to predict the future of obesity.

“This is exciting new evidence that epigenetic changes detectable at birth are linked to a child’s health as they grow up. Not only does it strengthen the body of evidence that shows a mother’s health during pregnancy can affect the future health of her child, but it could also allow us to more accurately predict the future risk of obesity. If we can do this, then strategies can be developed in early life to prevent the development of obesity,” she says.

Fellow researcher, Professor Keith Godfrey, from the Medical Research Council Lifecourse Epidemiology Unit says the findings provide the first direct evidence linking faltering of a baby’s growth in the womb with epigenetic modifications that themselves may increase the risk of childhood obesity.

“The findings are now helping us to trial new nutritional interventions before and during pregnancy to reduce the baby’s risk of obesity in childhood and later life, and strengthen the view that effective prevention of childhood obesity has to begin before the baby is born. The findings may also lead to innovative approaches to the treatment of established obesity in later life.”

You can read more about this study looking at epigenetic modifications and the future risk of obesity here.