A new study has revealed that a woman's diet before conception changes the functioning of her child's DNA.
According to the research, though it has been proved that the food taken by mothers affect the genes of their children, it has not been proved exactly how this happens.
As part of the research, scientists tracked women in rural Gambia, where rainy and dry periods influence diet in a big way. They selected 84 women who had conceived at the peak of the rainy season and about the same number who conceived at the peak of the dry season.
Infants from rainy season conceptions had higher rates of methylation in all six genes studied, the research said. These were associated with nutrients in the mother's blood.
Lead scientist Dr Branwen Hennig from the London School of Hygiene & Tropical Medicine said it was the first demonstration in humans that a mother's diet at the time of conception can alter her child's genes for life.
She told BBC News, "Our results have shown that maternal nutrition pre-conception and in early pregnancy is important and may have implications for health outcomes of the next generation."
Genes pass on directly from parents to children but alterations in DNA control the functioning of the genes. Previous experiments had shown in animals about how changes in DNA occur through mother's diet, but this had never been proved in humans.
One study in 2003 exhibited that a female mouse's diet can change her child's coat-colour through changes in its genes.
The findings were published in journal Nature Communications.