You Are What Your Mother Ate

Researchers have known that a pregnant mother’s diet can have a lasting impact on her child’s susceptibility to cancer, diabetes, obesity, and depression. Randy Jirtle, an oncologist at Duke University, is the first to decode the reason why. He and his colleagues studied dietary effects on two groups of genetically identical mice. The researchers fed one group of pregnant mice a normal diet. The second group ate the same food but also received a cocktail of B12, folic acid, choline, and betaine. The mice that got the extra nutrients had reduced expression of a gene that causes obesity, diabetes, and cancer. Jirtle says the nutrients probably help by providing a ready supply of methyl molecules, which act as stop signals at key places in the genome. “Roughly half of our DNA is junk—leftover bits of unnecessary genes and DNA fragments introduced by viruses. If we expressed all these genes, we’d ...