The link between environmental pollutants and rising rates of breast cancer will forever be linked as new research finds that women whose diets contain higher levels of cadmium are at greater risk of developing breast cancer than those who ingest less of the industrial chemical in their food.
According to the a Los Angeles Times report, a new observational study, published and released in Cancer Research, a journal of the American Association for Cancer Research, Thursday, found that among 55,987 post-menopausal women, the one-third with the highest cadmium intakes were 21% more likely to develop breast cancer than the one-third with the lowest intakes.
Cadmium, a heavy metal long identified as a carcinogen, leaches into crops from fertilizers and when rainfall or sewage sludge deposit it onto farmland. Whole grains, potatoes, other vegetables and shellfish are key dietary sources of cadmium, which also becomes airborne as a pollutant when fossil fuels are burned, and is likely inhaled as well as ingested.
Among obese women, the study found no increase in breast cancer rates with higher cadmium exposures.
The study offers new evidence in a large human population that environmental chemicals that mimic the effects of the female hormone estrogen may contribute to women’s risk of certain cancers, including endometrial and breast cancers.
The finding comes just three months after the Institute of Medicine, a prestigious body of independent biomedical researchers, concluded that a host of other factors — most within a woman’s power to control, such as obesity and hormone-replacement medication — were the most important sources of breast cancer risk.
The panel of experts had called it “biologically plausible” that estrogen-like pollutants promote breast cancers, but noted that evidence that they contribute significantly was inconclusive. By contrast, studies in human populations strongly point to fattening foods, hormone-replacement drugs, alcohol, and cigarettes as having roles in boosting a woman’s breast cancer risk.
Even this study, while showing a correlation, did not prove cause and effect, experts noted.