The synthetic hormones routinely injected into beef cattle in the US are a contributory factor to the development of breast cancer, the report says, while also pointing out the “association between higher lifetime consumption of grilled meats and fish and increased incidence of postmenopausal breast cancer”.
Other environmental factors include synthetic hormones in pharmaceuticals and cosmetics, pesticides in food, solvents in cleaning products, medical radiation treatments, BPA in food containers and flame retardants in furniture.
The report – State of the Evidence: The Connection Between Breast Cancer and the Environment – says that breast cancer is not simply a question of genetic history and lifestyle, and documents the additional environmental factors that also play a large part.
“A substantial body of scientific evidence indicates that exposures to common chemicals and radiation also contribute to the unacceptably high incidence of breast cancer,” said its lead author, Jane Gray of Vassar College.
Approximately 85,000 synthetic chemicals are registered for use in the US, more than 90 per cent of which have never been tested for their effect on human health. American women have a one in eight chance of getting breast cancer in their lifetime, with rates increasing by 40 per cent between 1973 and 1998 alone.
Among others, the study draws attention to the routine exposure of cattle and pigs to zearalenone and its synthetic derivative zeranol (Ralgro), oestrogenic compounds that are known to cause early-onset puberty in girls, a known risk factor for breast cancer.
Consumer fears over the use of growth-promoting hormones in cattle led to their being banned in Europe in 1989, and a ban on the import of all hormone-treated US beef, following a number of food scares in the 1970s. Organisations such as the Consumer Federation of America and the Center for Science in the Public Interest lobbied for the ban to be adopted within the US too.
To download the full study, click here