Updated: Jun 27
Bisphenol A (BPA) is a widely used synthetic compound found in our pantries and store cupboards, often in hard plastics and containers that store food such as plastic water bottles, food packaging, tinned foods, reusable containers, kitchen appliances and even printed store receipts. Worryingly, there is growing evidence that BPA may adversely affect health, it is a known an endocrine disrupter that could be contributing to thyroid issues, reproductive and developmental issues, metabolic disease and obesity.
BPA was first developed in 1891 by Aleksandr Dianin, in the 1930’s British chemical researcher Charles Edwards Dodds recognised BPA as a synthetic estrogen, he then created the structurally similar compound Diethylstilbestrol (DES) in the 1940's to treat conditions in pregnancy such as to prevent miscarriage and premature labour (1). The substance was then banned in the 1970’s for use in pregnancy following reports of both breast and rare vaginal cancers and fertility issues of the daughters born of the women who took DES in pregnancy. Sadly, DES didn’t only effect the children of the mothers who took the medication in pregnancy, it also affected the grandchildren of those that took the drug. They called it ‘DES syndrome’ and it was a generational disaster.
BPA although structurally similar to DES was never used in a drug, its future was in our plastic bottles, tin cans and Tupperware. There have been reports that BPA can mimic estrogen to interact with estrogen receptors, leading to changes in cell proliferation, apoptosis, or migration and thereby, contributing to cancer development and progression in particular hormonal cancers (such as breast and prostrate cancers) (2). The charity Breast Cancer UK are calling for the ban of BPA and argue that BPA should be classified as a carcinogen following a recently published review in the Journal of Reproductive Toxicology highlighting the carcinogenic properties of the synthetic compound. Laboratory experiments show that BPA has the ability to transform normal breast cells into cells of a more cancerous or overall malignant nature. They found substantial evidence that early-life BPA exposures increased susceptibility to mammary and prostate cancers (3,4,5).
High levels of BPA have been associated to female infertility. In an ART setting, high levels of BPA exposure have been shown to have reduced the number of oocytes retrieved, fertilised and implanted (6,7) there was an even stronger correlation found with BPA exposure and implantation failure in those undergoing the antagonist protocol (7). Unsurprisingly, a recent study demonstrated that BPA has been found to be more frequently detected in infertile women thus leading to hypothesise that a possible effect of BPA on natural conception (8).
It is understood that BPA disrupts fertility by dis-regulating the hypothalamus pituitary ovarian axis and has an impact on Gonadotropnin- releasing hormones (GnRH). The GnRH pulsatile release plays a key role in fertility, its responsible for the release of sex hormones Luteinising hormone (LH) and Follicle Stimulating hormone (FSH) from the pituitary. The regulation of these hormones is crucial in fertility and normalising the menstrual cycle as malfunction of the GnRH can lead to reproductive endocrine dysfunction such as polycystic ovarian syndrome (PCOS). Clinical trials found higher levels of BPA in the urine in the PCOS group compared with control group The results of this study indicated that BPA may play a major role in the PCOS pathogenesis (9).
Pregnant women and babies are at greater risk to the effects of BPA, and BPA has been found in the breast milk of nursing mothers. When published in 2010 The National Toxicology program had “some concern“ for BPA’s effects on the brain, behaviour, and prostate gland in foetuses, infants, and children at current exposure levels. BPA exposure in adulthood induces reversible damage in HPO axis function whereas prenatal and perinatal BPA exposure induces irreversible effects in female offsprings (6).
BPA exposure in childhood was associated with higher levels of anxiety, depression, hyperactivity, inattention, and conduct problems (10). Due to ethical grounds, the research on pregnant women and babies is unsurprisingly sparse. There have been some preliminary studies suggesting concerning findings so we look to the animal studies however there is a huge question mark hanging over whether these may or may not be transferable to humans.
Animal studies have demonstrated even more concerning findings, in a study looking at the effects of exposure of ‘safe’ levels BPA in-utero in mice demonstrated that three generations of female mouse offspring were effected experienced significant reproductive problems, including declines in fertility, sexual maturity and live birth rates (11).
Recent studies have demonstrated that BPA can negatively interfere with the regulation of spermatogenesis which can lead to sperm defragmentation. BPA is now recognised as a potent endocrine disruptor resulting in altered testis development, function, impaired endocrine function, and abnormal semen parameters (12). A 2011 cohort study provided the first epidemiological evidence of an adverse effect in semen quality. Increasing urine BPA level had more than three times the risk of lowered sperm concentration and lower sperm vitality, more than four times the risk of lower sperm count, and more than twice the risk of lower sperm motility (13).
In contrast, a 2020 literature review reassuringly concluded that fertile men with low unintentional environmental BPA exposure, any detectable effect on reproductive functions is likely to be small, with uncertain clinical significance…(14) A worthy consideration would be that sub-fertile men may be more susceptible to the effects of BPA than fertile men and high levels of exposure would be more detrimental. In researching the difference in levels of exposure, Lombó et al found that male zebrafish subjected to BPA levels of 2000 µg/L exhibited DNA fragmentation higher than 40%; 29% more than half of these suffered between 70 and 80% of fragmented DNA (15). The severity of defragmentation which triggered apoptosis and impaired early embryo survival. Maternal repair of DNA fragmentation in the oocyte is only possible in lower percentages of damage.
If it really is so bad, why isn’t it banned?
BPA was actually banned from baby bottles and sippy cups by the FDA in 2012 in response to a request by the plastics industry. In 2010 France banned the manufacture import and export of BPA in baby bottles, in 2012 this was extended to include all in food packages and utensils.
Breast Cancer UK have publicly called for a ban on all BPA products, Cancer research UK’s stance is that the data for concern of BPA is insufficient. A mixed interpretation of the same research brings confusion for the consumers. The FDA’s website also claimed that despite the decision to ban the use of BPA in baby bottles and sippy cups, there was no convincing evidence found that BPA is a hazard to people. The FDA has deemed that 50 micrograms of BPA per kilogram of body weight per day is a ‘safe amount’ and continues to monitor the research. In the UK, the European Food Safety Authority (EFSA) and the food standards agency have both also ruled the substance safe for use at current levels.
Inconsistencies in clinical trials and interpretations of findings prevent reclassification by policy makers. Some studies have demonstrated that the human body can eliminate a low level of BPA before it reaches the internal organs. The main issue with different interpretations and mixed findings comes from the lack of human data (although this field is growing) and it is very difficult to find a control group of people who have had no BPA exposure. Another issue is due to the risk suggested to pregnant women (as the strongest evidence for harm came from pregnant mice and their foetuses) it's simply being unethical to run such a trial in pregnant women.
BPA free plastics are safe, right?
Another controversial topic, with the rise in consumers avoiding BPA comes the rise in manufacturers using alternatives. These compounds are very similar in composition so may give a similar effect. It's important to be aware that products currently marketed as 'BPA free' are not ‘estrogenic activity free’ a 2011 study demonstrated that most plastics release estrogenic chemicals (16). A recent study found that alternative bisphenols such as bisphenol F (BPF) and bisphenol S (BPS) could disrupt thyroid function (17) and cause hypertension (18
Weighing up the evidence
A Landmark 2 year study, CLARITY-BPA, a U.S. government-sponsored guideline-compliant study and the present analysis aimed to provide some resolution of the controversy related to the toxicology of BPA. The study used BPA doses on rats and concluded low dosages of BPA to pose little risk to health (19). Other experts continue to disagree, critics have concerns about the study design and interpretation of the data.
A follow up study concluded that the CLARITY-BPA program results in rats and the FDA press release that BPA is safe might not be translatable to human exposure and potential negative health effects. Observational and cross-sectional studies have consistently showed that BPA exposure contributes to obesity, and has been linked to cardiovascular disease in adults (20).
Reputable health sources such as the the NHS website tread with caution acknowledging that BPA may mimic hormones and interfere with the endocrine system. The website discusses that some scientists believe that BPA interferes with sex hormones, and this could affect puberty, the menopause or cause cancers that are related to hormones. So why the discrepancy between the charities, studies and government guidelines?
The BPA safety war continues to divide and leave consumers confused, I often wonder what products we use in modern life will be the asbestos or lead paint of the future. Could it be electronic cigarettes? BPA? Parabens? Or something completely surprising? The research on BPA suggests that a level of BPA exposure could contribute to disrupting hormones in some people, whether that hormone disruption evolves into something more chronic or sinister is another question. The giant question mark hanging over BPA’s safety might be enough for consumers to avoid the controversial chemical, given the extensive research couples with interpretations of the research resulting in countries banning BPA in baby products or food packaging entirely, it's appropriate to be cautious about use of BPA and alternative plastics.
As a consumer, making the decision to make efforts to avoid BPA packaging sends a message directly to the manufacturers to encourage them to choose alternative packaging to plastics. In many cases, reducing your exposure to BPA will also mean reducing your plastic usage which can only be kinder on the environment and a great thing around!
My family try our best to avoid BPA and BPA alternate plastics reasonably and when possible. I do not believe it is possible to avoid exposure to BPA completely as its largely unavoidable and unrealistic. However, these small changes you could consider if you wanted to reduce plastic in your world which would be especially sensible if you are planning to start a family or you are breast feeding.
Tips to reduce exposure to BPA and BPA alternative plastics
These small changes can help you to reduce your BPA exposure, I am no way affiliated with any products that I have recommended, this is based on my personal experience in avoiding plastics.
1. Replace plastic kitchenware especially that comes into contact with heat (such as plastic soup makers/ blenders, plastic measuring jugs) the heat may break them down over time and allow BPA to leach into foods.
We replaced our much loved Ninja blender with the Tefal Easy Soup, all parts are stainless steel and it also makes smoothies too! You could also use a stainless steel stick blender. Ninja and nutribullets also offer stainless steel jugs which would reduce exposure to BPA, however, the lid is still plastic.
2. Do not place plastic containers in in the microwave or dishwasher, Replace with ceramic and glass, do not microwave plastic containers, especially with the recycle codes 3 or 7 as they may contain BPA.
3. Reduce use of plastic bottles
The degree to which BPA leaches from polycarbonate bottles into liquid depends on the temperature of the liquid or bottle and also the age of the container. Water drinking bottles in the sun are also considered to be at greater risk of leaching chemicals into the water for this reason.
It is not always possible or affordable but where you have a choice between plastic and glass opt for glass. We use the chilly’s water bottles and drink from glasses at home. For baby bottles we use Tommee Tippee Glass Bottles and store baby food in kilners baby food glass jars with a silicone lid.
4. Reduce use of canned foods
Some canned foods are still lined with the chemical BPA, or BPA alternatives with potentially similar risks. The safest way to avoid exposure is the most effective way to reduce exposure by reducing consuming tinned goods. We replaced our tinned tomatoes with passata jars and paper board cartons and coconut milk for cartons. We also switched our tinned chickpeas for dried chickpeas to be soaked overnight before cooking.
5. Reduce your consumption of plastic packaged foods
A recent study demonstrated that BPA levels found in participants urine reduced by 66% following 3 days of avoiding packaged foods. Its extremely hard to avoid this completely, through making better choices I hope that the food industry listen and adapt to plastic alternative packaging. Using markets, and self serve choosing fresh veggies at supermarkets, taking your own glass containers and waxed paper to restock your fridge and pantry where you can.
6. Avoid Receipts
Most printed store receipts contain BPA and BPS as it coats the thermal paper. Avoid them where possible or ask for them to be placed on an envelope for big ticket items that you may need to return. The daily petrol receipts, takeaway and food shop receipts that you are least likely to need you could decline. Shop workers and waiting staff have been found to have higher levels of BPA in their urine, most likely as a result of frequently handling receipts. If you work on a shop till and tough receipts more regularly than most you could consider wearing gloves.