Parabens found in cosmetics linked to breast cancer cells growth, says UC Berkeley research

According to the study, chemicals called parabens, which are widely used in shampoos, cosmetics, body lotions and sunscreens have been long associated with cancer because they imitate estrogens, which are known to increase the risk of breast cancer and reproductive problems.

University of California, Berkeley lead investigator Dale Leitman who is a gynaecologist and molecular biologist, said: "Although parabens are known to mimic the growth effects of estrogens on breast cancer cells, some consider their effect too weak to cause harm. But this might not be true when parabens are combined with other agents that regulate cell growth."

He added that the current chemical safety tests observe parabens separately and measure the effect of the chemicals on human cells. These tests do not take into account parabens behavior that could see the chemicals interacting with other types of signaling molecules in the human cells, thereby increasing the risk of breast cancer.

Dale Leitman, along with other study authors, observed breast cancer cells expressing two types of receptors: estrogen receptors and HER2. Around 25% of breast cancers give rise to an abundance of HER2 or human epidermal growth factor receptor 2. This type grows and spreads more quickly than other types of breast cancer.

The study authors activated the HER2 receptors in the breast cancer cells along with a growth factor called heregulin, which is naturally produced in breast cells.

The cells were then exposed to parabens. The effect was profound with the parabens triggering the estrogen receptors by activating the genes which caused the cells to multiply. The parabens present in the HER2 activated cells were able to activate breast cancer cell growth in concentrations that are 100 times lower than those compared to cells that were not exposed to heregulin.

The research shines light on the concerns about existing safety testing techniques especially whether the right potency of parabens in cosmetics and its effect on human health is being detected or not.

Co-author of the study Chris Vulpe said that the role played by substances apart from parabens which imitate estrogen may also have been underestimated by the current testing techniques.

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Image: Cosmetic items may contain parabens which are linked to breast cancer. Photo: Courtesy of jk1991/FreeDigitalPhotos.net.