Do plastics, Bisphenol A (BPA), increase your risk of breast cancer?

Bisphenols are multi-purpose chemicals which are used in many commercial products. Bisphenol A (BPA) is used to make polycarbonate plastics, the lining of many food cans, and some dental materials such as sealants and composite fillings.1 Due to consumer concerns over the possible health risks associated with using BPA-containing products, there has been a shift towards BPA alternatives, including bisphenol F (BPF) and bisphenol S (BPS).2 This post outlines how bisphenols can alter your hormones and explains why this may increase your risk for breast cancer.

Adverse health and hormonal effects
Many studies in humans have found a correlation between changes in hormone levels and exposure to Bisphenol A (BPA), both in adults and newborns. In addition, BPA binds strongly to estrogen receptors, and other receptors in the human body, which can directly disrupt hormone signalling.3 This disruption of hormones may be why Bisphenol A (BPA) exposure has been linked to a variety of conditions including: metabolic diseases such as type 2 diabetes, cardiovascular disease, and obesity, altered thyroid function, and reproductive dysfunction such as infertility, polycystic ovarian syndrome, and miscarriage. There is also a good body of research that suggests Bisphenol A (BPA) exposure can affect childhood behaviour and neurodevelopment.3 Despite being considered safer alternatives to Bisphenol A (BPA), numerous studies suggest BPS and BPF have similar abilities to disrupt hormones and exert estrogen-like effects in the body.2

Risk of breast cancer
Two studies have looked at the link between Bisphenol A (BPA) and breast cancer in humans. In their 2009 study Yang and colleagues found that the BPA blood levels in women with breast cancer were elevated relative to women without cancer, however, this value did not reach statistical significance.4 In a separate study, Aschengrau and others found no correlation between occupational exposure to Bisphenol A (BPA) and breast cancer diagnosis, but the study sample size was small.5 Unfortunately neither of these studies assessed lifetime BPA exposure or BPA exposure during fetal development in the uterus, which may be more important. There is evidence in both primates and rodents that fetal BPA exposure can change the breast tissue of these unborn animals, increasing their vulnerability to chemical carcinogens, which may then lead to the development of breast cancer later in life.3

So far there is no published research on BPS/BFP exposure and breast cancer risk. However, we know that these BPA alternatives do have estrogen-like activity and are likely just as potent as BPA. In hormone-sensitive cancers such as breast cancer, this needs to be taken seriously because estrogen can stimulate tumor growth. Studies of BPS and BPF exposure in humans are badly needed to determine whether these chemicals increase the risk of developing breast cancer.

The take-home message:
There is good evidence that bisphenol compounds have negative health consequences. The jury is still out on whether bisphenol compounds can increase breast cancer risk, however, they have been shown to disrupt hormone levels and have estrogen-like activity, which may have implications for hormone-sensitive cancers like breast cancer. So until more studies are done, it is probably a good idea to minimize your exposure to bisphenol-containing compounds as much as possible. Some of the ways you can do this are:

1. Drink out of glass, stainless steel, or ceramic water bottles and travel mugs.
2. Avoid using polycarbonate plastics to prepare or hold food as they may contain BPA. These are typically labelled with a recycling code 7. Remember BPA-free plastics may still contain BPS or BPF.
3. Choose fresh, frozen, or dried foods over canned alternatives whenever possible
4. If having dental work, talk to your dentist about the materials that are used and avoid BPA-containing fillings.

References

1. Canadian Cancer Society. Bisphenol A (BPA). Retrieved from http://www.cancer.ca/en/prevention-and-screening/be-aware/harmful-substances-and-environmental-risks/bpa/?region=on
2. Rochester JR, Bolden AL. Bisphenol A and F: A systematic review and comparison of the hormonal activity of bisphenol A substitutes. Environ Healh Perspect. 2015; 123(7): 643-650
3. Rochester JR. Bisphenol A and human health: a review of the literature. Reprod Toxicol. 2013; 42:132-155.
4. Yang M., Ryu J., Kang D., Yoo, K. Effects of bisphenol A on breast cancer and its risk factors. Arch Toxicol. 2009; 83(3):281-295
5. Aschengrau A, Coogan PF, Quinn M, Cashins LJ. Occupational exposure to estrogenic chemicals and the occurrence of breast cancer: an exploratory analysis. Am J Ind Med. 1998; 34:6-14. ­­­

You can also explore more details regarding cancer prevention here:

https://www.integratedhealthclinic.comprevention-survivorship/

Or contact us at the IHC Cancer Care Centre receptionist via email at cancercare@integratedhealthclinic.com or phone at 604-888-8325, option #1.

Sarah Soles, BSc., ND