FROM TARA PARKER-POPE AND THE NEW YORK TIMES:
Plastic Chemical May Interfere With Chemotherapy
A chemical widely used in hard plastic drinking bottles and the lining of food cans may reduce the effectiveness of chemotherapy treatment, a new study shows.
The findings, reported in the journal Environmental Health Perspectives, adds to the growing list of concerns about bisphenol-a, or BPA, a chemical used to make the hard, clear and nearly unbreakable plastic called polycarbonate. The plastic is also found in the lining of nearly every soft drink and canned food product.
Most of the concern about BPA has focused on children, who are exposed to the chemical when trace amounts leach from polycarbonate baby bottles and the linings of infant formula cans. The worry is based on data from animal studies. Rat pups exposed to BPA, through injection or food, showed changes in mammary and prostate tissue, suggesting a potential cancer risk. In some tests of female mice, exposure appeared to accelerate puberty.
In the latest research, a team from the University of Cincinnati studied human breast cancer cells, subjecting them to low levels of BPA similar to those found in the blood of adults. They found that BPA acts on cancer cells similar to the way estrogen does — by inducing proteins that protect the cells from chemotherapy agents.
“It’s actually acting by protecting existing cancer cells from dying in response to anti-cancer drugs, making chemotherapy significantly less effective,” said Nira Ben-Jonathan, a professor of cancer and cell biology who has studied BPA for more than 10 years.
The research may help explain why chemotherapy appears to be less effective in some patients.
“These data,” study authors write, “provide considerable support to the accumulating evidence that BPA is hazardous to human health.”
The study was funded by grants from the National Institutes of Health, the Department of Defense and the Susan G. Komen Breast Cancer Foundation.
The 2003-4 National Health and Nutrition Examination Survey by the Centers for Disease Control and Prevention found detectable levels of BPA in 93 percent of urine samples collected from more than 2,500 adults and children over 6.
In September, The Journal of the American Medical Association reported that adults with higher levels of BPA in their urine were more likely to have heart disease or diabetes. The Food and Drug Administration has reassured consumers that the chemical appears to be safe, but the National Toxicology Program , which is part of the Department of Health and Human Services, has raised concerns.
In September, the American Chemistry Council wrote this response to concerns about BPA:
And to learn more about our exposure to BPA and the chemical’s effects, read the New York Times’ recent Well column, A Hard Plastic Is Raising Hard Questions.