A mother’s diet before conception can alter her child’s genes permanently, potentially making them more prone to lifelong health problems, researchers found in a study published Tuesday in the online science journal Nature Communications
The children of women who conceived during Gambia’s lean season had different genetic markers on their DNA compared to the children of women who conceived during the harvest season, researchers from the London School of Hygiene and Tropical Medicine
, director of the MRC International Nutrition Group and one of the authors of the study, explained.
“I think everybody understands that we inherit our genes from our parents and that those are the main ways in which we resemble our parents and we inherit the characteristics they had," he said. "What fewer people know is that those genes can actually be altered and they can be altered by several processes, which are very complicated and not yet fully understood, but one of these involves adding little markers onto the genes, which can switch some genes on or turn them off."
Prentice and his colleagues studied how diet affects which genes are turned on or off by comparing two groups of women in rural Gambia: one that conceived during the dry season, when food is lacking in both quantity and quality, and one that conceived during the rainy season, when mothers have access to more protein and high-energy meals.
The researchers followed more than 2,000 women across 34 villages between July 2009 and July 2011.
Each time a woman gave birth, the researchers measured the markers on the baby's genes.
“To our great surprise, we found very strong effects in the different levels of markings, according to whether the babies had been conceived in the dry season or the rainy season. ... So what this tells us is that a mother’s diet in preparation for pregnancy or right at the moment of conception is highly crucial to how these genes are marked and that this almost inevitably will have lasting effects on their baby’s health,” Prentice said.
Researchers do not know precisely what the affected genes are responsible for, but are believed to determine susceptibility to cancer later in life, as well as weight gain and obesity, and the probability of dying from infectious diseases as a young adult.
In addition to folic acid, which has already been shown to help the development of babies, the study concluded vitamin B and a chemical compound known as choline, which is found in eggs and certain animal products, are necessary to achieving the “good” markings on the genes and improving the long-term health of a child.
Senior author Branwen Hennig
, senior investigator scientist with MRC in Gambia, said: "Our results represent the first demonstration in humans that a mother's nutritional well-being at the time of conception can change how her child's genes will be interpreted, with a life-long impact."
Prentice said, “Our ultimate goal is to define an optimal diet for mothers-to-be. ... Preconceptional folic acid is already used to prevent defects in embryos. Now our research is pointing towards the need for a cocktail of nutrients, which could come from the diet or from supplements.”