(HealthDay News) — In postmenopausal women, high dietary cadmium exposure is associated with an increased risk of developing breast cancer, after adjusting for other potential confounders, according to research published in the March 15 issue of Cancer Research.
Bettina Julin, of the Karolinska Institute in Stockholm, and colleagues conducted a population-based prospective cohort study involving 55,987 postmenopausal women to determine whether the intake of dietary cadmium, which has some estrogen mimetic characteristics, affects breast cancer risk.
During an average of 12.2 years of follow-up, the researchers identified 2,112 incident cases of invasive breast cancer. Of these, 1,626 were estrogen receptor positive and 290 were estrogen receptor negative. Compared with those with the lowest dietary cadmium intake, postmenopausal women with the highest dietary cadmium exposure were 21 percent more likely to develop breast cancer, after adjusting for other potential confounding factors (Ptrend = 0.02). Lean and normal-weight women had a 27 percent increased breast cancer risk for all tumors. Within each tertile of whole grain/vegetable consumption, the risk of breast cancer increased with increasing cadmium exposure, and within each tertile of cadmium exposure, the risk of breast cancer decreased with increasing consumption of whole grains/vegetables (Pinteraction = 0.73).
“In this large population-based prospective cohort of postmenopausal women, estimated dietary cadmium was associated with an increased breast cancer incidence,” the authors write. “The associations were more pronounced when taking the consumption of whole grain and vegetables into account, foods that account for about 40 percent of the dietary cadmium exposure, but that are also important sources of phytochemicals with proposed anticarcinogenic properties.”