March 16, 2012
New Study Links Cadmium Intake To Breast Cancer
A recent study, published in the journal Cancer Research, explains that dietary cadmium - a heavy metal long identified as a carcinogen which leaches into crops from fertilizers and when rainfall or sewage sludge deposit it onto farmland - can potentially increase a woman's risk for breast cancer, writes Christine Kearney for Medical News Today.
Associate professor Agneta Akesson, from the Karolinska Institute in Sweden said in a recent press release: “Because of a high accumulation in agricultural crops, the main sources of dietary cadmium are bread and other cereals, potatoes, root crops and vegetables. In general, these foods are also considered healthy.”
The 12-year study found that among 55,987 post-menopausal women, the one-third with the highest cadmium intakes were 21 percent more likely to develop breast cancer than the one-third with the lowest intakes. Among obese women, the study found no increase in breast cancer rates with higher cadmium exposures.
The finding comes just three months after the Institute of Medicine (IOM), 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 IOM 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.
A woman´s lifetime exposure to estrogen powerfully influences her risk. In animals and in laboratory tests, cadmium has been shown to exert estrogen-like effects more powerfully than other environmental pollutants, and so suspicion has fallen on the heavy metal as a possible promoter of breast cancer.
“Cadmium is receiving a lot of attention these days because of its estrogenic properties,” Rudolph Rull, a research scientist at the Cancer Prevention Institute of California in Berkeley, told Melissa Healy of the Los Angeles Times.
Both estrogen receptor-positive and negative tumors had the same risk increase at roughly 23 percent. Akesson said that women who consumed higher amounts of whole grain and vegetables had a lower risk of breast cancer compared to women exposed to dietary cadmium through other foods.
“It´s possible that this healthy diet to some extent can counteract the negative effect of cadmium, but our findings need to be confirmed with further studies,” said Ã kesson. “It is, however, important that the exposure to cadmium from all food is low.”