What is BPA? And why does it impact fertility?
What is BPA and how are we exposed to it?
Bisphenol A (BPA) is a synthetic compound, used since the 1950s in food packaging, plastics, industrial materials, and even dental fillers. Examples include its use as a coating on food & beverage cans and in making thermal paper, used in till receipts.
Everyone is exposed to BPA and we can absorb it into the body through skin, inhalation and the digestive system.
Exposure can be measured by urinary BPA levels, more than 90% of the population in western countries display detectable BPA levels in the urine.
Despite the European Union and Canada banning BPA use in baby bottles, it has still been found in the serum of babies fed by breast and fed by bottle. Exposure even begins prior to birth, with detectable concentrations of BPA measured in follicular fluid, amniotic fluid, placental tissue, and cord serum (1).
Why and how does exposure impact us?
BPA is considered an endocrine disrupter, as it can disrupt hormonal balance in the body. It has a weak estrogenic, antiandrogenic, and antithyroid activities. It can exert these effects by binding to hormone receptors in the body, mimicking or blocking the hormonal activity.
In 2017 the European Chemicals Agency has listed BPA as a substance of very high concern, due to its properties as an endocrine disruptor.
There is increasing evidence that BPA can impact human fertility:
A cohort human study found that preconception concentrations of BPA in female urine were associated with decreased fecundability (the probability of a women conceiving within a given time) (2).
Several studies have found that women with PCOS have a higher BPA concentrations than healthy women (3).
It is definitely not only relevant to female reproductive health. BPA has been found to disrupt sperm formation, both by binding to androgen receptors and also affecting Leydig cell steroidogenesis (cells in the testes that produce testosterone) (3).
Among couples attending an infertility clinic, urinary BPA levels were positively associated with sperm DNA damage (4). A study in China found that workers exposed to BPA, had significantly decreased self-reported sexual function when compare to the control group (5).
Increasing urine BPA levels were significantly associated with decreased concentration, sperm count, sperm vitality and sperm motility (6).
BPA found to promote mitochondrial dysfunction (our energy factories within cells) and oxidative/apoptotic damages to sperm in different species, including humans. In vitro studies on animal oocytes and sperm, found BPA was able to alter oxidative stress, which is responsible for reduced quality (7).
As with any, there are limitations to these studies. More research on BPAs toxic effects on reproductive organs will help to provide greater awareness of the potential threat this chemical represents to fertility.
How can we reduce our exposure?
Given the widespread use of BPA, complete avoidance to exposure is virtually impossible. However, there are definitely things we can do to actively lower our exposure.
10 tips to reduce your exposure
Say no to paper receipts – individual thermal receipts can contain BPA that is 250 to 1,000 times greater than the amount in a can of food (8). this is becoming easier with the increasing availability of email receipts. If you do need paper for expenses or the like, try to quickly snap a pic and then dispose of it.
Look for “non-toxic” on the products you purchase, don’t be afraid to enquire and ask manufacturers if their products contain BPA.
Try to reduce plastic food storage – swap plastic containers and lunch boxes for glass or stainless steel, you don’t have to rush out and buy all new containers – you can often collect and reuse old glass food jars. You can quickly build up a collection, my overflowing kitchen drawer is testament to this.
Avoiding heating plastics, or adding hot food to plastic containers instead allowing it to cool first (or even better, store in glass) – high temperatures increase the release of free BPA.
Swap BPA lined cans for dried foods, remember that heat can break down plastic and food manufacturers will heat metal cans lined with BPA to sterilise them. Also, acidic foods, such as tomatoes can break down plastic, so prioritise buying passata or chopped tomatoes in glass jars.
Use glass or stainless-steel water bottles.
Focus on fresh or frozen wholefoods in the diet, by doing this you naturally crowd out those in plastic and canned containers.
Chose plastic-free feminine hygiene products.
Swap cling film for reusable natural wraps, such as beeswax.
Decant food – decant any food and drinks that are only available in plastic packaging into glass or stainless storage containers when you get home.
1. Cantonwine DE, Hauser R, Meeker JD. Bisphenol A and Human Reproductive Health. Expert Rev Obstet Gynecol. 2013 Jul 1;8(4):10.1586/17474108.2013.811939.
2. Wang B, Zhou W, Zhu W, Chen L, Wang W, Tian Y, et al. Associations of female exposure to bisphenol A with fecundability: Evidence from a preconception cohort study. Environ Int. 2018 Aug 1;117:139–45.
3. Matuszczak E, Komarowska MD, Debek W, Hermanowicz A. The Impact of Bisphenol A on Fertility, Reproductive System, and Development: A Review of the Literature. Int J Endocrinol. 2019 Apr 10;2019:e4068717.
4. Meeker JD, Yang T, Ye X, Calafat AM, Hauser R. Urinary Concentrations of Parabens and Serum Hormone Levels, Semen Quality Parameters, and Sperm DNA Damage. Environ Health Perspect. 2011 Feb;119(2):252–7.
5. Li D-K, Zhou Z, Miao M, He Y, Qing D, Wu T, et al. Relationship Between Urine Bisphenol-A Level and Declining Male Sexual Function. J Androl. 2010;31(5):500–6.
6. Li D-K, Zhou Z, Miao M, He Y, Wang J, Ferber J, et al. Urine bisphenol-A (BPA) level in relation to semen quality. Fertil Steril. 2011 Feb 1;95(2):625-630.e4.
7. Nguyen M, Sabry R, Davis OS, Favetta LA. Effects of BPA, BPS, and BPF on Oxidative Stress and Antioxidant Enzyme Expression in Bovine Oocytes and Spermatozoa. Genes. 2022 Jan;13(1):142.
8. BPA and BPS in thermal paper [Internet]. Minnesota Pollution Control Agency. 2012 [cited 2022 Mar 23]. Available from: https://www.pca.state.mn.us/green-chemistry/bpa-thermal-paper