Tuesday, October 27, 2015
Chemicals in personal products may stimulate cancer more than thought
Parabens are a type of chemical preservative, and are found in a wide array of consumer products, including shampoos, body lotions and sunscreens.
It's also known that parabens can activate the same pathway as estrogen, but previous studies have found that they do so very weakly, Leitman told Live Science. "Because they're weak, they're assumed to be safe compounds," especially based on the levels of parabens that have been found in humans, he said.
But previous studies looked at just the parabens by themselves, Leitman said.
"The real problem when you do studies in the laboratory is that you study one compound at a time, but in the body, that's not the case. What you're seeing in the body is really a combination" of the effects of many compounds, Leitman said.
In the new study, published today (Oct. 27) in the journal Environmental Health Perspectives, the researchers focused on the effects of parabens when mixed with one additional compound: a type of growth factor called heregulin that has also been linked to breast cancer cell growth.
In experiments, the researchers looked at how well the cells grew when they were exposed to both parabens and heregulin, compared with how the cells grew when exposed only to parabens. The scientists found that when they added heregulin, they could drop the level of parabens by 100 times and the cancer cells would still multiply faster than those without heregulin.