Yue "Joseph" Wang of the Virginia Tech Research Center in Arlington and colleagues at Georgetown University said pregnant rats on a diet supplemented with synthetic estrogen or with fat -- which increases estrogen levels -- produce ensuing generations of daughters that appear to be healthy but harbor a greater risk for mammary cancer.
The study, published in the journal Nature Communications, said although the findings have not yet been validated in humans, the study shows that environmental damage may be passed from one generation to the next not via genetic mutations, but through "epigenetic" alterations that influence how genomic information is decoded.
"We have shown for the first time that altered DNA methylations modulated by specific diet in normal development are heritable and transgenerational," Wang said in a statement.
Virginia Tech researchers developed mathematical models and machine-learning techniques to analyze the changes in DNA methylation -- allowing cells with the same genome to perform different functions by adding chemical groups to DNA to turn some genes on and some genes off -- status in the descending daughters to understand how increased cancer risk is transmitted without genetic mutation.
"Ultimately, it might be possible to undo or prevent this harmful methylation and decrease the risk of breast cancer," Wang said.