Mothers' diets before pregnancy could have lifelong effects on babies' health, says study

A mother’s diet before becoming pregnant can alter the way her baby’s genes function, potentially leading to “permanent, lifelong effects” on its health, scientists have said.

In the first study to show how eating habits at the time of conception can affect human genes, a team from the London School of Hygiene and Tropical Medicine [LSHTM], analysed blood samples from more than 160 babies born in rural Gambia.

Half of the babies were born in the rainy season, and the other half in the dry. Marked seasonal differences in the country mean that diets vary significantly at different times of the year. Babies conceived during the rainy season were found to have higher rates of a particular chemical compound – known as methyl groups – in their genes than babies born in the dry season.

Although the researchers said it was not yet possible to determine what consequences the difference might have for the children’s health, it is the first time such an effect has been seen in humans, having previously been observed in mice, whose coat colour can be varied by changes in the mother’s diet.

While a child’s genes are inherited directly from their parents, the way those genes function can be altered by modifications to the DNA that can be caused by environmental factors – such as diet – known as epigenetic changes.

Scientists said the findings of their study, published in Nature Communications, “opens up the possibility that a mother’s diet before pregnancy could permanently affect many aspects of her children’s lifelong health.”

Andrew Prentice, professor of international nutrition at LSHTM said: “Our ultimate goal is to define an optimal diet for mothers-to-be that would prevent defects in the methylation process.”