Friday, March 14, 2014

Can your water bottle cause prostate cancer?

Bisphenol A, otherwise known as BPA, is a common chemical used to make hard plastics and epoxy resins.  It is commonly found in many household items including water bottles, cans and paper products like receipts.  BPA was initially synthesized as a synthetic estrogen, but has been used in manufacturing due to its strong chemical cross-linking abilities.  Estrogen exposure has been related to prostate carcinogenesis in rat models [1] and an increased risk of prostate cancer in men.[2]

A recent study in PLOS (Public Library of Science) One looked at the urine of 60 urology patients and found higher levels of BPA in the urine of prostate cancer patients when compared to non-prostate cancer patients.  Interestingly, they found this difference to be even more pronounced in men less than 65 years in age, indicating that early, lifelong exposure may lead to an increased rate of prostate cancer.  In addition, by looking at prostate cancer cell lines in vitro, the authors also found that even low levels of BPA could disrupt cell duplication cycle and lead to prostate cancer development.[3]

Tarapore et al. PLOS One. [3]

Another study, from researchers at the University of Cincinatti, demonstrated that exposing neonatal mice to estrogens or BPA created epigenetic changes in the DNA of prostate genes.  These epigenetic changes to methyl groups that bind to DNA constitutively turn on genes that lead to prostate cell growth and make prostate cancers more likely.[4]

In summation, these studies indicate that long-term, low-level exposure to BPA may make subtle changes to the DNA of prostate cells that make the progression to cancer more likely.

So does BPA cause prostate cancer?

While these studies (and others like them) are very provocative, they are merely studies of association.  They demonstrate some strong relationships between BPA and the development of prostate cancer, however, they do not demontrate that BPA causes prostate cancer.  There are many factors both genetic and from the environment that may cause prostate cancer, and BPA may play a role in the multifactorial development of cancer, but is not the primary cause of prostate cancer.

Your water bottles are safe... for now!

[1] Leav I, Ho S, Ofner P, Merk F, Kwan P, Damassa D. Biochemical alterations in sex hormone-induced hyperplasia and dysplasia of the dorsolateral prostates of Noble rats. J Natl Cancer Inst. 1988;80:1045–1053.
[2] Modugno F, Weissfeld JL, Trump DL, et al. Allelic variants of aromatase and androgen and estrogen receptors: toward a multigenic model of prostate cancer risk. Clin Cancer Res. 2001;7:3092–3096. 
[3] Tarapore P, Ying J, Ouyang B, Burke B, Bracken B, et al. (2014) Exposure to Bisphenol A Correlates with Early-Onset Prostate Cancer and Promotes Centrosome Amplification and Anchorage-Independent Growth In Vitro. PLoS ONE 9(3): e90332. doi:10.1371/journal.pone.0090332
[4] Shuk-Mei Ho,1 Wan-Yee Tang,1 Jessica Belmonte de Frausto,2 and Gail S. Prins2.  Developmental Exposure to Estradiol and Bisphenol A Increases Susceptibility to Prostate Carcinogenesis and Epigenetically Regulates Phosphodiesterase Type 4 Variant 4. Cancer Res. Jun 1, 2006; 66(11): 5624–5632.;jsessionid=BkHVzQU6aLDs2MNLk4KD.12

No comments:

Post a Comment