HealthDay News –High exposure to dietary cadmium, a toxic metal present in many fertilizers believed to have estrogen mimetic characteristics, was associated with an increased risk for developing breast cancer among postmenopausal women, study findings indicate.
Women who had the highest exposure to dietary cadmium had a 21% increased risk for breast cancer (P for trend= 0.02) compared with those who ate the lowest levels, and this risk increased to 27% in lean and normal weight women, Agneta Akesson, PhD, associate professor at Karolinska Institute in Sweden, and colleagues reported in Cancer Research.
“Because of a high accumulation in agricultural crops, the main sources of dietary cadmium are bread and other cereals, potatoes, root crops and vegetables,” Akesson said in a press release. “In general these foods are also considered healthy.”
The researchers used food frequency questionnaires to estimate dietary cadmium exposure among a population-based cohort of 55,987 postmenopausal women. During the 12-year follow-up period there were 2,112 incidences of breast cancer, including 1,626 estrogen receptor-positive and 290 estrogen receptor-negative cases.
Despite the increased risk for breast cancer observed among women who had high levels of cadmium exposure, Akesson and collegues found that those who ate more whole grain and vegetables had a lower risk compared with women exposed to dietary cadmium through other foods.
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 (P interaction = 0.73).
“It’s possible that this healthy diet to some extent can counteract the negative effect of cadmium but our findings need to be confirmed with further studies,” Akesson said. He added that it’s important to note that exposure to cadmium in food is generally low.