WOMEN who eat a fatty diet when pregnant could unwittingly be increasing the risk of their daughters and granddaughters getting breast cancer, research has shown.
Chronic exposure to hormone-like chemicals in food and drinking water may have a similar effect down the generations, evidence suggests.
The findings, from a study of rats, could explain why breast cancer often runs in families, even though known inherited genes account for only a small number of cases.
Researchers fed pregnant female rats a high-fat diet from before conception to the time they gave birth.
Their daughters were 55 per cent to 60 per cent more likely to develop breast cancer than animals whose mothers were fed a normal diet.
Pregnant rats given synthetic oestrogen in their food had daughters with a 50 per cent higher chance of breast cancer.
Chemicals with oestrogenic properties are abundant in plastics, paints, food packaging and electrical equipment. Though they are present at low non-toxic levels, experts believe that long-term exposure to such “endocrine disrupting chemicals” (EDCs) could have important biological effects on fertility and other aspects of health.
Lead scientist Dr Sonia de Assis, from Georgetown University in Washington in the United States, said the study could have implications for human health.
“Could a woman’s susceptibility to breast cancer development be determined by what her grandmother ate when she was pregnant, or if she was exposed to high levels of oestrogen – perhaps unwittingly – through the environment?” she said.
The findings, published in the latest online edition of the journal Nature Communications, are believed to result from environmental effects on genes.
But Sarah Williams, health information officer at Cancer Research UK, urged caution over the American study.
She said: “This study was carried out in rats, so we can’t say whether similar effects could be seen in people.”