Researchers warn that pregnant women who gorge on junk food are increasing the risk of breast cancer - not just theirs, but also down the generations.
In their rat-based study, researchers at Georgetown Lombardi Comprehensive Cancer Center showed that pregnant females that ate a high fat diet not only increased breast cancer risk in their female daughters but also in that daughter's offspring - the "granddaughters."
Details of the study will be presented at the AACR 101st Annual Meeting 2010.
The researchers say they don't know why this risk is passed on through two generations, but they believe it occurs through as-yet unknown "epigenetic" changes that result in an increase in terminal end buds in the breast tissue - an increase that apparently can then be passed on through generations.
These buds are believed to be the structures where breast cancer can develop, and having more of these structures seems to increase breast cancer risk, says the study's lead investigator, Sonia de Assis, Ph.D., a postdoctoral fellow in Leena Hilakivi-Clarke's laboratory at Lombardi. "That is our theory, but we really don't know how it is happening - just yet."
The researchers add that while the grandmother ate a diet that was 43 percent fat,she didn't eat more calories than a control population of rats, and both her daughters and granddaughters ate a normal chow.
The researchers also found that the risk appears to not only extend from mother to daughter and granddaughter, but also from mother to son to granddaughter.
"The implications from this study are that pregnant mothers need to eat a well balanced diet because they may be affecting the future health of their daughters and granddaughters," says de Assis.