Dietary Cadmium, Breast Cancer Link?
Highest Exposure Levels Linked to 21% Increased Risk, but More Study Needed, Researchers Say
Vegetables, Whole Grains May Offset Risk
Women who ate diets high in whole grains and vegetables appeared to be protected, Julin found.
It's not certain why. It could be due to the antioxidant properties of the foods, the researchers say.
The study was funded by the Swedish Cancer Society, the Swedish Research Council for Environment, Agricultural Sciences and Spatial Planning, and the Swedish Research Council/Research Infrastructures.
Cadmium and Breast Cancer Risk: Perspective
"This is a very solid study that is likely to be influential in getting cadmium classified as either a breast carcinogen or a breast tumor promoter," says Kenneth Portier, PhD, managing director of the Statistics & Evaluation Center for the American Cancer Society.
He reviewed the findings for WebMD.
The new study ties in what researchers know about cadmium exposure from laboratory and animal studies and extends it to its effect in women, he says.
Exactly why cadmium is linked to risk is not clear. Portier suspects it is the estrogen-like properties of the cadmium. "Recent research has demonstrated that cadmium can operate like estrogen in the body, and we know from other data that estrogen promotes cancer growth."
These effects would be most evident in women past menopause, he says. That is because they have less estrogen. As a result, they are sensitive to increases in estrogen from outside the body.
"In women who have gone through menopause, you have to be concerned about anything that may increase estrogen levels -- including dietary sources," he tells WebMD.
However, he urges women to put the risk in perspective. Many other factors affect breast cancer risk, he says. Among them:
- Family history of breast cancer
- Excess alcohol intake
- Inactive lifestyle
More research is needed, he tells WebMD, to figure out how to reduce possible risk due to cadmium.