Understanding Bisphenol A (BPA): Risks and Impacts on Health
Bisphenol A (BPA) is a widely used synthetic compound found in many household items, particularly in hard plastics and food storage containers. Common sources include plastic water bottles, food packaging, canned foods, reusable containers, kitchen appliances, and even printed store receipts. Alarmingly, growing evidence suggests that BPA may have adverse effects on human health.
The Endocrine Disruption
BPA is recognised as an endocrine disruptor, a chemical that interferes with the normal functioning of the endocrine system, which regulates reproductive and other biological processes. Endocrine disruptors like BPA have been linked to a range of health issues, including thyroid disorders, reproductive and developmental problems, metabolic diseases, and obesity.
Historical Background
BPA was first synthesised in 1891 by Aleksandr Dianin. In the 1930s, British chemical researcher Charles Edwards Dodds identified BPA as a synthetic estrogen. In the 1940s, he developed a structurally similar compound called Diethylstilbestrol (DES), which was used to treat pregnancy complications, such as preventing miscarriage and premature labor. However, DES was banned in the 1970s after reports emerged linking its use during pregnancy to breast and rare vaginal cancers, as well as fertility issues in the daughters of women who took DES. Tragically, the consequences of DES extended beyond the first generation, impacting the grandchildren of those who were exposed—a phenomenon termed “DES syndrome” that represented a generational health crisis.
BPA’s Role in Health Concerns
Although BPA shares a similar structure with DES, it was never used in pharmaceuticals. Instead, its application became widespread in consumer products like plastic bottles, tin cans, and Tupperware. Research has shown that BPA can mimic estrogen, interacting with estrogen receptors and leading to changes in cell proliferation, apoptosis (programmed cell death), and migration. This mimicry has been linked to the development and progression of certain cancers, particularly hormone-related cancers such as breast and prostate cancer.
Breast Cancer UK has been vocal in its call for a ban on BPA, advocating for its classification as a carcinogen. A recent review published in the Journal of Reproductive Toxicology highlighted the carcinogenic properties of this synthetic compound. Laboratory studies have demonstrated that BPA can transform normal breast cells into more malignant forms, and substantial evidence indicates that early-life exposure to BPA increases susceptibility to mammary and prostate cancers.
BPA and Its Impact on Female Fertility
High levels of Bisphenol A (BPA) have been linked to female infertility. In assisted reproductive technology (ART) settings, increased BPA exposure has been associated with a reduced number of oocytes retrieved, fertilized, and implanted. Notably, a stronger correlation has been found between BPA exposure and implantation failure, particularly among those undergoing the antagonist protocol. Recent studies have also detected higher levels of BPA in infertile women, suggesting a potential negative effect on natural conception.
Mechanisms of Disruption
BPA disrupts fertility primarily by dysregulating the hypothalamic-pituitary-ovarian (HPO) axis, which significantly impacts the release of gonadotropin-releasing hormones (GnRH). The pulsatile release of GnRH is crucial for fertility as it stimulates the release of sex hormones—luteinizing hormone (LH) and follicle-stimulating hormone (FSH)—from the pituitary gland. Proper regulation of these hormones is essential for maintaining fertility and normalizing the menstrual cycle. Dysfunction of GnRH can lead to reproductive endocrine disorders, such as polycystic ovarian syndrome (PCOS). Clinical trials have shown higher levels of BPA in the urine of women with PCOS compared to a control group, indicating that BPA may play a significant role in the pathogenesis of this condition.
Risks to Pregnant Women and Infants
Pregnant women and infants are particularly vulnerable to the effects of BPA, which has been detected in the breast milk of nursing mothers. In 2010, the National Toxicology Program expressed “some concern” regarding BPA’s effects on the brain, behavior, and prostate gland in fetuses, infants, and children at current exposure levels. While BPA exposure in adulthood may induce reversible damage to HPO axis function, prenatal and perinatal exposure has been linked to irreversible effects in female offspring.
Moreover, BPA exposure during childhood has been associated with increased levels of anxiety, depression, hyperactivity, inattention, and conduct problems. Due to ethical considerations, research involving pregnant women and infants is limited. Preliminary studies have raised concerning findings, leading researchers to turn to animal studies; however, whether these results can be extrapolated to humans remains uncertain.
Animal Studies and Generational Impact
Animal studies have yielded alarming results. For instance, research examining the effects of “safe” levels of BPA exposure in utero in mice demonstrated significant reproductive problems across three generations of female offspring. These included declines in fertility, sexual maturity, and live birth rates, raising serious concerns about the long-term effects of BPA exposure.
The Impact of BPA on Male Fertility
Recent studies have shown that Bisphenol A (BPA) can adversely affect spermatogenesis, leading to sperm fragmentation. Recognized as a potent endocrine disruptor, BPA can alter testis development and function, impair endocrine function, and result in abnormal semen parameters. A landmark cohort study in 2011 provided the first epidemiological evidence linking increased BPA exposure to compromised semen quality. Specifically, higher urine BPA levels were associated with more than three times the risk of decreased sperm concentration and vitality, over four times the risk of lower sperm count, and more than double the risk of reduced sperm motility.
Contrasting Findings
In contrast, a 2020 literature review suggested that for fertile men with low unintentional environmental BPA exposure, any detectable effect on reproductive functions is likely to be minimal, with uncertain clinical significance. However, it is essential to consider that sub-fertile men may be more vulnerable to the negative effects of BPA compared to their fertile counterparts. Higher levels of BPA exposure could be particularly detrimental to this group.
Research by Lombó et al. highlighted the differences in BPA exposure effects, demonstrating that male zebrafish subjected to BPA levels of 2000 µg/L experienced over 40% DNA fragmentation. Notably, more than half of these fish exhibited between 70% and 80% DNA fragmentation, leading to severe outcomes such as apoptosis and impaired early embryo survival. It is important to note that maternal repair of DNA fragmentation in oocytes is only feasible at lower percentages of damage, further emphasizing the potential reproductive risks associated with high BPA exposure.
If it really is so bad, why isn’t it banned?
Bisphenol A (BPA) has been the subject of increasing scrutiny, leading to some regulatory actions but also ongoing debate. In 2012, the FDA banned BPA from baby bottles and sippy cups in response to requests from the plastics industry. France took a more comprehensive approach by banning the manufacture, import, and export of BPA in baby bottles in 2010, subsequently extending this ban to all food packaging and utensils in 2012.
Calls for a Broader Ban
Organisations like Breast Cancer UK have publicly called for a complete ban on all BPA-containing products. In contrast, Cancer Research UK maintains that the current data concerning BPA's risks is insufficient to warrant such a ban. This mixed interpretation of research findings creates confusion for consumers seeking clarity on BPA’s safety.
The FDA has asserted that, despite banning BPA in baby bottles and sippy cups, there is no convincing evidence that BPA poses a hazard to human health. The agency has established a “safe” threshold of 50 micrograms of BPA per kilogram of body weight per day, and it continues to monitor emerging research. In the UK, both the European Food Safety Authority (EFSA) and the Food Standards Agency have similarly ruled that BPA is safe for use at current exposure levels.
Challenges in Research and Regulation
Inconsistencies in clinical trials and differing interpretations of findings hinder reclassification efforts by policymakers. Some studies suggest that the human body can effectively eliminate low levels of BPA before they reach internal organs. However, the mixed results stem from a lack of comprehensive human data—although this field is expanding. Finding a control group of individuals with no BPA exposure is particularly challenging.
Another significant obstacle arises from the ethical implications of conducting trials on pregnant women. The strongest evidence of BPA's potential harm has been derived from studies on pregnant mice and their offspring, making it unethical to replicate such trials in humans.
BPA free plastics are safe, right?
The rise in consumer demand for BPA-free products has led many manufacturers to seek alternatives to this controversial compound. However, the safety of these substitutes is another contentious topic. Many of these alternative compounds share similar chemical structures with BPA and may produce similar hormonal effects.
It's crucial to understand that products labeled as "BPA-free" are not necessarily free from estrogenic activity. A 2011 study revealed that most plastics release estrogenic chemicals, raising concerns about their potential impact on health. More recent research has identified that alternative bisphenols, such as bisphenol F (BPF) and bisphenol S (BPS), may disrupt thyroid function and contribute to hypertension.
Given these findings, consumers should remain cautious about the implications of switching to BPA-free products, as they may still pose health risks.
The Controversy Surrounding BPA Safety
A landmark two-year study known as CLARITY-BPA, sponsored by the U.S. government, aimed to address the ongoing debate surrounding the toxicology of BPA. This guideline-compliant study administered BPA doses to rats and concluded that low levels of BPA pose little risk to health. However, experts remain divided, with critics raising concerns about the study's design and the interpretation of its data.
A follow-up analysis suggested that the results from the CLARITY-BPA program and the FDA's assertion that BPA is safe may not be applicable to human exposure and its potential health effects. Observational and cross-sectional studies have consistently indicated that BPA exposure is linked to obesity and cardiovascular disease in adults.
Reputable health organisations, such as the NHS, urge caution, acknowledging that BPA can mimic hormones and interfere with the endocrine system. They highlight concerns that BPA may disrupt sex hormones, potentially impacting puberty, menopause, or contributing to hormone-related cancers. This raises the question: why is there such a discrepancy between various charities, studies, and government guidelines?
The "BPA safety war" continues to divide opinions, leaving consumers in a state of confusion. One can't help but wonder which products in modern life may become the asbestos or lead paint of the future—could it be electronic cigarettes, BPA, parabens, or something entirely unexpected? Research suggests that BPA exposure could disrupt hormones in some individuals; whether such disruption leads to chronic or serious health issues remains uncertain.
Given the extensive research and differing interpretations, some countries have opted to ban BPA in baby products and food packaging altogether, making it prudent for consumers to be cautious.
As consumers, choosing to avoid BPA packaging sends a clear message to manufacturers, encouraging them to adopt safer alternatives. Reducing BPA exposure often translates to reduced plastic usage, benefiting both personal health and the environment.
In my family, we strive to limit our exposure to BPA and its alternatives whenever possible. While completely avoiding BPA is unrealistic due to its pervasive presence, there are small, manageable changes that can help. This approach is particularly sensible for those planning to start a family or currently breastfeeding.
Tips to Reduce Exposure to BPA and BPA Alternative Plastics
Implementing these small changes can help reduce your BPA exposure. I have no affiliations with the products mentioned; these tips are based on my personal experiences in avoiding plastics.
Replace Plastic Kitchenware:
Especially items that come into contact with heat (e.g., plastic soup makers, blenders, measuring jugs). Heat can cause plastic to break down and allow BPA to leach into foods. We swapped our beloved Ninja blender for the Tefal Easy Soup, which is made entirely of stainless steel and also makes smoothies! Alternatively, consider a stainless steel stick blender or stainless steel jugs from brands like Ninja and Nutribullet (though note the lids may still be plastic).
2. Avoid Microwaving and Dishwashing Plastic:
Do not place plastic containers in the microwave or dishwasher. Instead, opt for ceramic and glass containers, as microwaving plastics—especially those with recycling codes 3 or 7—can increase BPA leaching.
3. Reduce Use of Plastic Bottles:
BPA leaches from polycarbonate bottles depending on temperature and the container's age. Water bottles left in the sun are particularly at risk. Whenever possible, choose glass over plastic. We use Chilly’s water bottles and drink from glasses at home. For baby bottles, we prefer Tommee Tippee glass bottles and store baby food in Kilner glass jars with silicone lids.
4. Limit Canned Foods:
Some canned foods may still be lined with BPA or its alternatives. The best way to minimize exposure is to reduce consumption of tinned goods. We switched from canned tomatoes to jarred passata, carton coconut milk, and from canned chickpeas to dried chickpeas soaked overnight before cooking.
5. Minimise Plastic-Packaged Foods:
A recent study found that BPA levels in participants' urine decreased by 66% after three days of avoiding packaged foods. Although it's challenging to eliminate plastic completely, making better choices can encourage the food industry to adopt alternative packaging. Consider shopping at markets, opting for fresh veggies, and bringing your own glass containers or waxed paper for storage.
6. Avoid Receipts:
Most printed receipts contain BPA and BPS due to thermal paper coatings. Where possible, decline receipts or request they be placed in an envelope for larger purchases. Daily receipts from petrol stations and grocery shops can usually be skipped. Shop workers handling receipts regularly show higher BPA levels in their urine; those in retail may consider wearing gloves.
7. Swap Your Coffee Machine:
Consider using a glass French press instead of a coffee machine, as some machines have BPA in their reservoirs. If you continue using a coffee machine, fill the reservoir with water just before use and empty it afterward to minimise water sitting in plastic.
8. Replace Reusable Food Storage Containers:
Prioritise replacing damaged or old containers that have been exposed to heat. Use glass, stainless steel, and porcelain for storing hot foods instead of plastic. We replaced all our measuring jugs and food storage containers with glass and opted for a stylish stainless steel bento box for lunches.
9. Upgrade Your Utensils:
Swap out plastic colanders for inexpensive stainless steel alternatives and replace plastic spatulas with silicone or wooden options.
10. Drink Filtered Tap Water
While many health experts recommend drinking filtered water, if your filtered water sits in a plastic jug, consider investing in a stainless steel or glass filtration system. We’ve attached a filter directly to our kitchen tap to ensure our cold water is free from plastic exposure.
11. Avoid Plastic Straws:
There are numerous wonderful alternatives to plastic straws; I particularly enjoy glass straws. I haven’t yet tried bamboo or silicone straws but would love to hear your experiences with them!
12. Replace Ice Trays:
Opt for silicone ice trays made from 100% food-grade silicone. Avoid unclassified silicone, which may contain plastics that can leach chemicals.
13. Drink Loose Leaf Tea:
Many tea bags contain microplastics from polypropylene used to seal them, rendering them non-compostable. Some brands offer natural sealing methods without plastics, such as Clipper, Pukka Herbs, and Tea Pigs. You can check out recommendations for plastic-free tea bags in this article from The Independent.
14. Swap Plastic Baby Toys:
Choose wooden or silicone toys instead of plastic ones, especially if they are left in the sun, which can cause BPA to leach out. We love Haakaa silicone teethers and natural wooden toys.
A Final Word
Small, gradual swaps can significantly reduce your BPA exposure, starting with higher-risk items first. This approach is particularly wise for those planning to start a family or for nursing mothers. It’s important to remember that BPA is not the only potentially toxic chemical in our environment—non-stick pans, pesticides, mold, and phthalates also pose risks. Choosing alternatives when possible can help minimise your overall exposure.
Being aware of BPA’s potential harm may prompt you to think twice about drinking from that water bottle left in the sun or a hot car all day. It might encourage you to reach for a reusable stainless steel or glass bottle instead, which is not only healthier but also better for the environment.
Do you have any favourite swaps? I’d love to hear about them in the comments below!
References:
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