Can parabens cause breast cancer and hormonal disorders?
Can parabens cause breast cancer or hormonal disorders? Photo: Wikimedia
Can parabens cause breast cancer and hormonal disorders?
It has been claimed that parabens, found in many cosmetic products, can cause both breast cancer and hormonal disorders. But is this true?
Methyl, ethyl, propyl, butyl, and benzyl parabens are all esters of p -hydroxybenzoic acid. These are used as antimicrobial preservatives in cosmetics, drugs, food og drink. Due to their low production cost and low toxicity, they are used worldwide.
Can the body get rid of parabens?
Yes, after parabens reach the bloodstream, they can be conjugated in the liver with glycine, sulfate, or glucoronate, and then excreted in the urine.
However, some parabens are lipophilic, which results in them being absorbed through the skin and found in the tissue when tested. In fact, in studies, accumulations of between 20 ng / g tissue ratio and 100 ng / g tissue ratio have been detected. (1)
Can parabens cause breast cancer?
Parabens have a weak estrogenic activity and, in micro-studies (in vitro), have induced growth of the breast cancer cells MCF-7. (2)
There are such results that have led to speculation that parabens may promote breast cancer. Among other things, it is claimed in studies that more and more breast cancer cases start in the upper part of the breast, in the area where deodorant is applied. (3) Another study believes that the estrogenic effect is too small to pose a real problem to MCF-7 cells or any other health risk. (4)
Can parabens lead to higher levels of estrogen and earlier puberty?
Another, more indirect, way in which parabens can affect estrogenic activity is by inhibiting the enzyme sulfotransferase's activity in the cytosol (cytoplasm outside the organelles in the cell) on the skin cells.
By blocking the sulfotransferase enzymes, the paraben may indirectly lead to a higher level of estrogen. (5) Some believe that parabens are one of the reasons why girls reach puberty at an ever younger age, as estrogen levels become higher, thus speeding up the process.
- Certain forms of parabens can block mitochondrial activity
Another, more indirect, way in which parabens can affect estrogenic activity is by inhibiting the enzyme sulfotransferase's activity in the cytosol (cytoplasm outside the organelles in the cell) on the skin cells.
The mitochondria are the cell's energy center. This is where most of the ATP (adenosine triphosphate) energy is generated. Methyl and propyl parabens are both substances that prevent this type of mitochondrial activity. (6, 7) But a systematic review of studies concludes that it is 'Biologically unlikely that parabens can increase the risk of any estrogen-mediated endpoint, including effects on male fertility and breast cancer.' (6) Sorry, but we just have to translate that conclusion into Norwegian.
"(…) It is biologically implausible that parabens could increase the risk of any estrogen-mediated endpoint, including effects on the male reproductive tract or breast cancer."
The conclusion is…
Research has not been able to show that parabens are directly dangerous… but based on the results we can probably conclude that it is not directly healthy either.
It would be best to exercise the use of paraben-containing products wisely. As with everything else. Take small steps to reduce parabens, such as using a paraben-free sunscreen.
It is possible that future research will give us even clearer answers on how parabens affect us, but as of now, research indicates that they are not very dangerous, but not something you want too much of.
Sources / Studies:
1. Ji K1, Lim Kho Y, Park Y, Choi K. Influence of a five-day vegetarian diet on urinary levels of antibiotics and phthalate metabolites: a pilot study with «Temple Stay» participants. About Res. 2010 May; 110 (4): 375-82. doi: 10.1016 / j.envres.2010.02.008. Epub 2010 Mar 12.
2. Darbre PD1, Aljarrah A, Miller WR, Coldham NG, Sauer MJ, Pope GS. Concentrations of parabens in human breast tumors. J Appl Toxicol. 2004 Jan-Feb;24(1):5-13.
3. Xiaoyun Ye, Amber M. Bishop, John A. Reidy, Larry L. Needhamand Antonia M. Calafat. Parabens as Urinary Biomarkers of Exposure in Humans. Environ Health Perspect. 2006 Dec; 114 (12): 1843–1846.
4. Byford JR1, Shaw LE, Drew MG, Pope GS, Sauer MJ, Darbre PD. Estrogenic activity of parabens in MCF7 human breast cancer cells. J Steroid Biochem Mol Biol. 2002 Jan;80(1):49-60.
5. Darbre PD1, Harvey PW. Paraben esters: review of recent studies of endocrine toxicity, absorption, esterase and human exposure, and discussion of potential human health risks. J Appl Toxicol. 2008 Jul;28(5):561-78. doi: 10.1002/jat.1358.
6.Golden R1, Gandy J, Vollmer G. A review of the endocrine activity of parabens and implications for potential risks to human health. Crit Rev Toxicol. 2005 Jun;35(5):435-58.
7. Prusakiewicz JJ1, Harville HM, Zhang Y, Ackermann C, Foreman RL. Parabens inhibit human skin estrogen sulfotransferase activity: possible link to paraben estrogenic effects. Toxicology. 2007 Apr 11; 232 (3): 248-56. Epub 2007 Jan 19.
It has been claimed that parabens, found in many cosmetic products, can cause both breast cancer and hormonal disorders. But is this true?
A systematic review study in 2006 showed that it is biologically unlikely that parabens may affect male fertility or promote breast cancer.
"(…) It is biologically implausible that parabens could increase the risk of any estrogen-mediated endpoint, including effects on the male reproductive tract or breast cancer." (Golden et al, 2006)
However, what has been seen in some studies is that both hormonal and mitochondrial activity can be affected by certain parabens.