Adding to the evidence that your baby’s health may be influenced by the nine months it spends in the womb, a new study finds that a pregnant mother’s diet may be associated with her child’s later risk of obesity.
A team of researchers from Australia, Singapore and the U.K. found that mothers who had diets low in carbohydrates during pregnancy bore children who showed certain changes to their DNA. The researchers then tied those genetic changes to body fat at age 6 and 9.
(More on TIME.com: A New Health Site in Beta Testing for Pregnant Women, New Moms)
The DNA changes the researchers measured weren’t actual mutations to genes. They were so-called epigenetic changes to the cellular material that sits on top of genes and modifies how they are expressed. The epigenome acts as a dial, turning up and down the expression of various genes. Previously, other scientists have argued that such epigenetic changes — the most common type is known as DNA methylation — can be passed onto future generations.
In the current study, researchers identified certain epigenetic markers associated with metabolic function that could be measured in the umbilical cord, and then tested the umbilical cords of 300 children for those markers. The researchers also asked the mothers to fill out food questionnaires during pregnancy.
(More on TIME.com: When Mom Exercises in Pregnancy, Her Baby’s Heart Benefits)
The study found that children born to women who ate lower-carb diets during pregnancy were more likely to have the relevant epigenetic markers in their umbilical cords. Those epigenetic changes were then associated with increased body fat at ages 6 and 9.
Reported the BBC:
Professor Keith Godfrey, who is from the University of Southampton and led the international study, told the BBC: “What is surprising is that it explains a quarter of the difference in the fatness of children six to nine years later.”
The report says the effect was “considerably greater” than that of birth weight and did not depend on how thin or fat the mother was.
The changes were noticed in the RXRA gene. This makes a receptor for vitamin A, which is involved in the way cells process fat.
It’s important to note that the study, published in the journal Diabetes, was small, and did not show cause or effect, but merely associations between maternal diet, epigenetic changes and later childhood weight. But a growing body of evidence suggests that the impact of epigenetic changes — in addition to a person’s genes and environmental influences — is important in determining good health. What influences the epigenome? Research has linked changes to it with environment factors like pollution and lifestyle factors like smoking, stress and diet.
(More on TIME.com: Obese Women Are More Likely to Miscarry or Endure a Baby’s Death)