A new UC San Diego study suggests that the byproducts of a chemical used in plastic found in the lining of cans may disrupt human hormone function more than the chemical itself.
The study, published today in PLOS ONE, may help explain why the chemical bisphenol A, or BPA, has been tied to many health problems even though the chemical doesn’t have a strong effect on cells in a Petri dish.
“We have a candidate chemical that is doing the nasty stuff, or the endocrine disruption," said study co-author and UCSD structural biologist Michael E. Baker. "We know that BPA exposure causes a lot of endocrine problems, but if you’re analyzing BPA in urine, you may not be analyzing the chemical that’s really doing the endocrine disruption."
Several studies have linked BPA exposure to health problems such as breast cancer and birth defects in animals and humans. Researchers say the chemical may be harmful because it mimics hormones such as estrogen. A 2003-04 National Health and Nutrition Examination Survey found more than 90 percent of participants tested had measurable levels of the chemical in their urine.
But when BPA is put into a dish with cells that bind to estrogen, the cells don’t proliferate, Baker said. For instance, breast cancer cells may grow prolifically in the presence of estrogen, but would need much more BPA to see the same growth, he said.