FAQ: Parabens and Breast Cancer
Oct. 27, 2015 — A new study has found that chemicals called parabens can spur the growth of certain types of breast cancer cells. And they appear to be able to do this even in tiny amounts.
Parabens are used in many food and personal care products. They have a chemical structure that’s similar to estrogen, which means they can mimic the effects of that hormone in the body. But they seem do this weakly, and on the scale of chemical threats, researchers thought parabens were pretty low on the list of things to worry about.
New research suggests, though, that they may be more harmful than previously thought.
For the study, scientists grew breast cancer cells in a lab. They treated the cancer cells with low doses of parabens along with heregulin, a growth-promoting substance that’s normally found in breast tissue. The two chemicals are known to have a more powerful effect when combined.
When the two chemicals were combined, the dose of parabens needed to stimulate growth was 100 times lower. That suggests parabens may be exerting effects at levels people are being exposed to in real life, according to study author Ruthann Rudel, who co-directs the research program for the non-profit Silent Spring Institute.
WebMD asked experts to discuss the findings.
Q: What are parabens?
They’re preservatives. They prevent bacteria from growing in things like face moisturizer, which repeatedly comes into contact with germs from your hands as you scoop it out to apply it to your face. The American Chemical Society estimates that parabens are in about 85% of personal care products — everything from shampoo to shaving cream. Researchers believe most of us get our greatest exposure from these products as they’re absorbed through the skin.
Parabens can also be found in foods like baked goods, beverages, syrups, jellies, jams and preserves, in the packaging that keeps food fresh, and in drugs, according to the CDC’s National Biomonitoring Program.
The most commonly used parabens are methylparaben, propylparaben, and butylparaben, according to the FDA.
Q: Who is exposed to them?