High Levels of Dietary Cadmium Raise Breast Cancer Risk

PHILADELPHIAWomen who consume high levels of dietary cadmium, commonly found in agricultural fertilizers, may increase their risk for breast cancer by more than 20%, according to a new study published in the Cancer Research.

Researchers at the Karolinska Institutet in Sweden observed 55,987 women for more than 12 years. They estimated the dietary cadmium exposure using a food frequency questionnaire. During the follow-up period, researchers observed 2,112 incidences of breast cancer including 1,626 estrogen receptor-positive and 290 estrogen receptor-negative cases.

Cadmium consumption was divided into three groups with the highest levels of exposure compared with the lowest. Overall, a higher exposure to cadmium via diet was linked with a 21% increase in breast cancer. Among lean and normal weight women, the increased risk was 27%. Both estrogen receptor-positive and negative tumors had the same risk increase at roughly 23%. Interestingly, women who consumed higher amounts of whole grains and vegetables had a lower risk of breast cancer compared to women exposed to dietary cadmium through other foods.

Because of a high accumulation in agricultural crops, the main sources of dietary cadmium are bread and other cereals, potatoes, root crops and vegetables," the researchers said. In general, these foods are also considered healthy. It is, however, important that the exposure to cadmium from all food is low."