Ingesting higher levels of cadmium, a metal found in fertilizers, may be linked to an increased risk of breast cancer, a new study from Sweden suggests.
The results showed that postmenopausal women with a relatively high daily dietary cadmium intake had a 21 percent increased risk of breast cancer.
The major sources of cadmium in the diets of women in the study were foods that are generally healthy whole grains and vegetables. These accounted for about 40 percent of the cadmium consumed.
The reason for the link may be that cadmium can cause the same effects in the body as the female hormone estrogen, the researchers said. Estrogen fuels the development of some breast cancers.
Whole grains and vegetables generally protect against cancer, and people should not avoid these foods because of this study, said study researcher Agneta kesson, associate professor at Karolinska Institutet in Sweden.
The study showed an association, not a cause-and-effect link, in one population of women, and further work is needed to confirm the findings.
"Though no single observational study can be considered conclusive, this very large, prospective study of [cadmium] exposure and post-menopausal breast cancer makes an important contribution to what is a fairly sparse literature considering this very important topic," said Michael Bloom, a professor at the School of Public Health at the University of Albany, who was not involved in the study.
"It has been known for some time that cadmium is toxic and, in certain forms, carcinogenic," said study researcher Bettina Julin, of the Karolinska Institute of Environmental Medicine.
In the study, the researchers collected data from more than 55,000 women in Sweden for 12 years. The women kept a daily log of everything they ate. The researchers estimated how much cadmium the women's consumed based on the country's data on the amount of cadmium in foods, and divided the women into three equally-sized groups based on their intake.
Over the course of the study, there were 2,112 breast cancer cases among the women: 677 in the women in the lowest cadmium intake group, and 744 in the women in the highest cadmium intake group. Because women's risk of breast cancer rises with age, the researchers took the women's ages into account when calculated the increased risk seen in the high intake group.
Originally posted here:
Fertilizer May Increase Risk of Breast Cancer