(CBS News) Next time you're eating, you might want to skip the cadmium-heavy foods. A new study says consuming too much cadmium may increase a woman's chances to get breast cancer.
What's cadmium? It's a toxic metal commonly found in the environment, especially in farm fertilizers.
According to a new study published in Cancer Research, women who consumed a lot of dietary cadmium had a 21 percent higher chance of developing breast cancer. Cadmium can also be found in the air through the burning of fossil fuels, according to the Environmental Protection Agency.
"Because of a high accumulation in agricultural crops, the main sources of dietary cadmium are bread and other cereals, potatoes, root crops and vegetables," study author Dr. Agneta Akesson, associate professor of environmental science at Karolinska Institute in Sweden, said in a written statement. "In general, these foods are also considered healthy."
The study observed almost 56,000 people for over 12 years. Participants were asked to estimate their dietary cadmium exposure through a food frequency questionnaire. During follow-up, researchers found that 2,112 women developed breast cancer, including 1,626 estrogen receptor-positive cases - which means estrogen made the cancers grow. Researchers divided the participants into groups of high, medium and low cadmium consumption, and found the women in the highest group were 21 percent more likely to develop breast cancer. The number jumps to 27 percent in women who are considered lean or at normal weight.
Cadmium - a soft white silver metal - has similar estrogen-like qualities, which can fuel breast cancer. The EPA declared cadmium a possible human carcinogen, after repeated exposure to the metal was linked to lung and kidney diseases. It has been linked to lung cancer via long-term inhalation in animals, but it is still inconclusive if it causes lung cancer in humans.
Cadmium was also recently found in high levels in some low-cost costume jewelry according to a non-profit environmental group test,reported. The U.S. Consumer Product Safety Commission (CPSC) said they were looking into the matter.
While the easiest way to be exposed to cadmium is through airborne particles, food is generally the second largest source for non-smokers. Those who smoke have about twice the amount of cadmium in their bodies than non-smokers.
That doesn't mean that people should avoid eating vegetables or grains. Women in the study who ate a lot of whole grains and vegetables had a lower risk of breast cancer compared to women who were exposed to the cadmium through other foods. The researchers also said the overall breast cancer risk from eating cadmium is still low compared to other risk factors like family history and obesity.