Study: Exposure to Cadmium May Up Breast Cancer Risk

New research in rats suggests that the heavy metal cadmium -- found in soil, rocks and water -- mimics the effects of the female hormone estrogen and may trigger development of breast cancer.

Human exposure to cadmium can occur from eating food grown in contaminated soil or shellfish from tainted water, and also from smoking cigarettes or exposure to certain industrial activities.

Reporting in the journal Nature Medicine, researchers from Georgetown University Medical Center said they injected rats with doses of cadmium similar to what humans might be exposed to and found it caused significant changes in responses normally regulated by estrogen.

The researchers said exposure induced an increase in uterine weight, changes in the lining of the uterus and an increase in the density of epithelial cells in the mammary glands -- all early signs of breast cancer.

"The ability of environmentally relevant amounts of cadmium to mimic the effects of estradiol [estrogen] suggests the metal may represent a new class of endocrine disrupters," the researchers said.

"The results of the present study show that cadmium has potent estrogen-like activity," the researchers concluded. "This means that cadmium might be a risk factor for breast cancer."

Other Sources: Nature Medicine