A child’s risk of obesity as they grow up can be influenced by modifications to their DNA prior to birth, a new University of Southampton study has shown.

These changes, known as 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 the development of the embryo and the formation of different cell types, regulating when and where genes are switched on. 

DNA methylation can be affected by a range of environmental factors such as parental health, diet and lifestyle.

Researchers from the University of Southampton, as part of the EpiGen Global Consortium, analysed the levels of DNA methylation at the SLC6A4 gene which is an important mediator in serotonin levels in the body and has been implicated in mood and appetite regulation.

The samples were taken umbilical cord tissue of babies born in the Southampton Women’s Survey at birth and compared with the amount of fat tissue in the child at four and six years of age.

They found that lower DNA methylation levels at the SLC6A4 gene at birth was associated with a higher fat mass at six to seven years of age. Each unit lower SLC6A4 methylation at birth was associated with a 7 percent higher child’s fat mass at age six years.*

The Southampton team compared the results to the mother’s health during pregnancy and found that higher weight gain during pregnancy and a lower number of previous births was associated with lower SLC6A4 DNA methylation.

Co-lead author Karen Lillycrop, from the University of Southampton, said: “Our results add to the growing evidence that epigenetic changes detectable at birth are linked to a child’s health as they grow up. Additionally, it also strengthens the body of evidence that shows a mother’s health during pregnancy can affect the future health of her child, and it could allow us to more accurately predict the future risk of obesity.”

The results, published in the International Journal of Obesity were replicated in other groups of children and adults, notably the Western Australian Pregnancy Cohort Study and the UK BIOCLAIMS cohort.

This latest Southampton study is another example of how the health of parents before and during pregnancy can affect the health of their future baby. This will be the topic of debate at a Question Time-style event on Thursday 21 November entitled ‘Fake Food’.

The event, organised by the Institute for Developmental Sciences at the University, will include a panel of experts taking audience questions and discussing the big food issues that matter from the very earliest points of development and across the life course. It is a free event which anyone can attend.

Emma Garratt, co-lead author, from the University of Southampton, said: “These results offer more evidence and more opportunity to allow us to develop strategies and interventions in early life that could reduce childhood obesity rates.”

Professor Keith Godfrey, a member of the research team and Director of the EpiGen Global Consortium, added: “The new findings strengthen the case that primary prevention of childhood obesity needs to begin before birth, and might ‘re-set’ appetite levels in ways that protect infants and children from putting on excessive weight. Ongoing research is examining whether diet and lifestyle interventions before and during pregnancy might be able to tackle and even reverse the childhood obesity epidemic.”

Notes to editors

1. Paper details.
2. *This statistic was derived from a 1 Standard Deviations change in methylation being associated with a 0.22 Standard Deviation change in fat mass at age 6 years; the 5.8 kg 5^th-95^th centile range of fat mass equates to ~4 Standard Deviations, so 1 Standard Deviation approximates to 1.45 kg & 0.22 Standard Deviations to 0.32 kg; a 0.32 kg reduction from the average fat mass is ~7 per cent.

3. The panel at the Fake Food event on the 21^st November 2018 will consist of:
   Nathan Atkinson, Headteacher and creator of Fuel for Schools
   Dr Sarah Jarvis MBE, GP, Clinical Director of @patient and Resident doctor on BBC R2 Jeremy Vine show
   Prof Mark Hanson, University of Southampton, IDS director
   Prof Guy Poppy, Chief Scientific Adviser to Food Standards Agency, Ecologist
   Prof Sian Robinson, University of Southampton, Nutritional Epidemiologist
   Dr Giles Yeo,Appetite and obesity scientist, author and BBC broadcaster

4. The EpiGen Global Consortium brings together expertise from the Human Development and Health Academic Unit, MRC Lifecourse Epidemiology Unit and Centre for Biological Sciences, University of Southampton; Singapore Institute for Clinical Sciences; National University of Singapore; Auckland UniServices Limited and the Liggins Institute, University of Auckland.  The Consortium’s aim is to improve human health through the life course by further understanding developmental and environmental processes. The research includes a focus on epigenetics, the biology of understanding how gene function is regulated by environmental factors, such as maternal nutrition, during the very early stages of development. This research was carried out as part of a collaboration with Nestlé Research, in Lausanne, Switzerland.   

More information about the Fake Food event can be found at https://www.eventbrite.co.uk/e/fake-food-question-time-tickets-47417615364?aff=ebdssbdestsearch