BPA is an industrial chemical that may find its way into your food and beverages.
Some experts claim that it is toxic and that people should make an effort to avoid it.
But you may wonder if it’s really that harmful.
This article provides a detailed review of BPA and its health effects.
BPA (bisphenol A) is a chemical that is added to many commercial products, including food containers and hygiene products.
It was first discovered in the 1890s, but chemists in the 1950s realized that it could be mixed with other compounds to produce strong and resilient plastics.
These days, BPA-containing plastics are commonly used in food containers, baby bottles, and other items.
BPA is also used to make epoxy resins, which are spread on the inner lining of canned food containers to keep the metal from corroding and breaking.
SUMMARY BPA is a synthetic compound found in many plastics, as well as in the lining of canned food containers.
Common products that may contain BPA include:
- Items packaged in plastic containers
- Canned foods
- Feminine hygiene products
- Thermal printer receipts
- CDs and DVDs
- Household electronics
- Eyeglass lenses
- Sports equipment
- Dental filling sealants
It's worth noting that many BPA-free products have merely replaced BPA with bisphenol-S (BPS) or bisphenol-F (BPF).
However, even small concentrations of BPS and BPF may disrupt the function of your cells in a way similar to BPA. Thus, BPA-free bottles may not be an adequate solution ().
Plastic items labeled with the recycling numbers 3 and 7 or the letters "PC" likely contain BPA, BPS, or BPF.
SUMMARY BPA and its alternatives — BPS and BPF — may be found in many commonly used products, which are often labeled with recycling codes 3 or 7 or the letters "PC."
The main source of BPA exposure is through your diet ().
When BPA containers are made, not all of the BPA gets sealed into the product. This allows part of it to break free and mix with the container's contents once food or fluids are added (, ).
For instance, a recent study found that BPA levels in urine decreased by 66% following three days during which participants avoided packaged foods ().
Another study had people eat one serving of either fresh or canned soup daily for five days. Urine levels of BPA were 1,221% higher in those who consumed the canned soup ().
Additionally, WHO reported that BPA levels in breastfed babies were up to eight times lower than those in babies fed liquid formula from BPA-containing bottles (7).
SUMMARY Your diet — particularly packaged and canned foods — is by far the biggest source of BPA. Babies fed formula from BPA-containing bottles also have high levels in their bodies.
Many experts claim that BPA is harmful — but others disagree.
This section explains what BPA does in the body and why its health effects remain controversial.
BPA's Biological Mechanisms
BPA is said to mimic the structure and function of the hormone estrogen ().
Due to its estrogen-like shape, BPA can bind to estrogen receptors and influence bodily processes, such as growth, cell repair, fetal development, energy levels, and reproduction.
In addition, BPA may also interact with other hormone receptors, such as those for your thyroid, thus altering their function ().
Your body is sensitive to changes in hormone levels, which is the reason why BPA's ability to mimic estrogen is believed to affect your health.
The BPA Controversy
Given the information above, many people wonder whether BPA should be banned.
Its use has already been restricted in the EU, Canada, China, and Malaysia — particularly in products for babies and young children.
Some US states have followed suit, but no federal regulations have been instituted.
In 2014, the FDA released its latest report, which confirmed the original 1980s daily exposure limit of 23 mcg per pound of body weight (50 mcg per kg) and concluded that BPA is probably safe at the levels currently allowed (9).
However, research in rodents shows negative effects of BPA at much lower levels — as little as 4.5 mcg per pound (10 mcg per kg) daily.
What’s more, research in monkeys shows that levels equivalent to those currently measured in humans have negative effects on reproduction (, ).
One review revealed that all the industry-funded studies found no effects of BPA exposure, while 92% of the studies not funded by industry found significant negative effects ().
SUMMARY BPA has a similar structure as the hormone estrogen. It may bind to estrogen receptors, affecting many bodily functions.
BPA may affect several aspects of your fertility.
One study observed that women with frequent miscarriages had about three times as much BPA in their blood as women with successful pregnancies ().
What's more, studies of women undergoing fertility treatments showed that those with higher levels of BPA have proportionally lower egg production and are up to two times less likely to become pregnant (, ).
Among couples undergoing in vitro fertilization (IVF), men with the highest BPA levels were 30–46% more likely to produce lower-quality embryos ().
A separate study found that men with higher BPA levels were 3–4 times more likely to have a low sperm concentration and low sperm count ().
Additionally, men working in BPA manufacturing companies in China reported 4.5 times more erectile difficulty and less overall sexual satisfaction than other men ().
Although such effects are notable, several recent reviews agree that more studies are needed to strengthen the body of evidence (, , , ).
SUMMARY Several studies show that BPA can negatively affect many aspects of both male and female fertility.
Most studies — but not all — have observed that children born to mothers exposed to BPA at work weigh up to 0.5 pounds (0.2 kg) less at birth, on average, than children of unexposed mothers (, , ).
Children born to parents exposed to BPA also tended to have a shorter distance from the anus to the genitalia, which further points to BPA's hormonal effects during development ().
In addition, children born to mothers with higher BPA levels were more hyperactive, anxious, and depressed. They also showed 1.5 times more emotional reactivity and 1.1 times more aggressiveness (, , ).
Finally, BPA exposure during early life is also thought to influence prostate and breast tissue development in ways that increase cancer risk.
However, while there are ample animal studies to support this, human studies are less conclusive (, , , , 33, ).
SUMMARY BPA exposure during early life may influence birth weight, hormonal development, behavior, and cancer risk in later life.
Human studies report a 27–135% greater risk of high blood pressure in people with high BPA levels (, ).
Moreover, a survey in 1,455 Americans linked higher BPA levels to an 18–63% greater risk of heart disease and a 21–60% greater risk of diabetes ().
In another study, higher BPA levels were linked to a 68–130% higher risk of type 2 diabetes ().
What’s more, people with the highest BPA levels were 37% more likely to have insulin resistance, a key driver of metabolic syndrome and type 2 diabetes ().
However, some studies found no links between BPA and these diseases (, , ).
SUMMARY Higher BPA levels are associated with an increased risk of type 2 diabetes, high blood pressure, and heart disease.
Obese women may have BPA levels 47% higher than those of their normal-weight counterparts ().
Several studies also report that people with the highest BPA levels are 50–85% more likely to be obese and 59% more likely to have a large waist circumference — though not all studies agree (, , , , , ).
Interestingly, similar patterns have been observed in children and adolescents (, ).
Although prenatal exposure to BPA is linked to increased weight gain in animals, this has not been strongly confirmed in humans (, ).
SUMMARY BPA exposure is linked to an increased risk of obesity and waist circumference. However, more research is needed.
BPA exposure may also be linked to the following health issues:
- Polycystic ovary syndrome (PCOS): BPA levels may be 46% higher in women with PCOS, compared to women without PCOS ().
- Premature delivery: Women with higher BPA levels during pregnancy were 91% more likely to deliver before 37 weeks ().
- Asthma: Higher prenatal exposure to BPA is linked to a 130% higher risk of wheezing in infants under six months old. Early childhood exposure to BPA is also linked to wheezing later in childhood (, ).
- Liver function: Higher BPA levels are linked to a 29% higher risk of abnormal liver enzyme levels ().
- Immune function: BPA levels may contribute to worse immune function ().
- Thyroid function: Higher BPA levels are linked to abnormal levels of thyroid hormones, indicating impaired thyroid function (, , ).
- Brain function: African green monkeys exposed to BPA levels judged safe by the Environmental Protection Agency (EPA) showed loss of connections between brain cells (59).
SUMMARY BPA exposure has also been linked to several other health problems, such as issues with brain, liver, thyroid, and immune function. More research is needed to confirm these findings.
Given all of the potential negative effects, you may wish to avoid BPA.
Although eradicating it completely may be impossible, there are some effective ways to reduce your exposure:
- Avoid packaged foods: Eat mostly fresh, whole foods. Stay away from canned foods or foods packaged in plastic containers labeled with recycling numbers 3 or 7 or the letters "PC."
- Drink from glass bottles: Buy liquids that come in glass bottles instead of plastic bottles or cans, and use glass baby bottles instead of plastic ones.
- Stay away from BPA products: As much as possible, limit your contact with receipts, as these contain high levels of BPA.
- Be selective with toys: Make sure that plastic toys you buy for your children are made from BPA-free material — especially for toys your little ones are likely to chew or suck on.
- Don't microwave plastic: Microwave and store food in glass rather than plastic.
- Buy powdered infant formula: Some experts recommend powders over liquids from BPA containers, as liquid is likely to absorb more BPA from the container.
SUMMARY There are several simple ways to reduce your exposure to BPA from your diet and environment.
In light of the evidence, it’s best to take steps to limit your BPA exposure and other potential food toxins.
In particular, pregnant women may benefit from avoiding BPA — especially during the early stages of pregnancy.
As for others, occasionally drinking from a "PC" plastic bottle or eating from a can is probably not a reason to panic.
That said, swapping plastic containers for BPA-free ones requires very little effort for a potentially big health impact.
If you aim to eat fresh, whole foods, you’ll automatically limit your BPA exposure.