BPA-free

BPA (bisphenol A) is an industrial chemical that is found in many foods and drinks. Some experts say that this compound is toxic and that we should try to avoid it as much as possible. Many consumers wonder if BPA is really that dangerous. This article provides a detailed overview of BPA and its effects on health.

What is BPA?

BPA is short for Bisphenol A - a chemical that is added to many commercial products including food containers. BPA was first discovered in the 1990s, but it wasn't until the 1950s that chemists realized that BPA could be combined with other compounds to make strong and durable plastic products.

Today, plastic containers containing BPA are widely used and include food containers, baby bottles and other products.

BPA is also used to make epoxy resins, which are applied to the inner surface of canned food to prevent corrosion and cracking of the metal.

Which products contain BPA?

Common products that contain BPA include

Products packaged in plastic containers
Canned foods
Cosmetic products
feminine hygiene products
DVDs are CDs
household electrical appliances
Plastic spectacle lenses
Sports equipment
Sealants for dental fillings

It is worth noting that in many BPA-free products, BPA has merely been replaced by bisphenol-S (BPS) or bisphenol-F (BPF).

However, even low concentrations of BPS and BPF can disrupt the function of the body's cells in a similar way to BPA. Thus, BPA-free bottles may not be an adequate solution to the problem (1).

How does BPA enter the body?

The largest amount of BPA enters the body through food (2). When BPA containers are manufactured, not all BPA is sealed in the product. This means that some of it can be released and mix with the contents of the container once food or drink has been poured into it (3, 4).

For example, a recent study found that BPA levels in urine decreased by 66% three days after subjects began avoiding packaged foods (5). In another study, subjects ate either a serving of fresh soup or a serving of canned soup every day for 5 days. BPA urine levels were 1,221% higher in the subjects who consumed the canned soup (6).

In addition, the WHO reported that BPA levels were up to eight times lower in breast-fed infants than in babies fed liquid formula from BPA-containing bottles (7).

Is BPA bad for your health?

Many experts say that BPA is harmful, while others disagree. In the following sections, we'll take a look at what BPA does in the body and why its effects on health are controversial.

The biological mechanisms of BPA

BPA is said to mimic the structure and function of the hormone estrogen (2). Due to its estrogen-like structure, BPA can bind to the estrogen receptor and influence body processes such as growth, cell repair, fetal development, energy levels and reproduction.

In addition, BPA may interact with other hormone receptors such as thyroid hormone receptors, thereby altering their function (8). The body is very sensitive to changes in hormone levels, so it is believed that BPA's ability to mimic estrogen could affect health.

The BPA controversy

Based on the above information, many people are wondering whether BPA should be banned. The use of this compound is already restricted in the EU, Canada, China and other countries, especially for products intended for babies and young children. Restrictions also apply in some states in the USA, but there are no nationwide regulations. In 2014, the U.S. Food and Drug Administration (FDA) published a report confirming the limits from the 1980s, which stated that 50 mcg of BPA per kilogram of body weight per day is likely safe and harmless (9). However, recent rodent studies show adverse effects of BPA at much lower levels in the range of 10 mcg per kilogram per day. In addition, studies conducted with monkeys show that levels equivalent to those measured in humans have negative effects on reproduction (10, 11). A study review showed that all industry-funded studies observed no adverse effects of BPA, while 92% of non-industry-funded studies observed significant adverse effects (12).

Summary: BPA has a similar structure to the hormone estrogen. It may bind to the estrogen receptor and interfere with many bodily functions.

BPA could cause infertility in men and women

BPA could affect several aspects of fertility. One study observed that women who had frequent miscarriages had about three times higher levels of BPA in their blood than women who had successful pregnancies (13). In addition, studies of women undergoing fertility treatment have shown that the women with higher BPA levels had proportionally lower egg production and were half as likely to become pregnant (14, 15). In couples who underwent artificial insemination, men with the highest BPA levels were 30 to 40% more likely to conceive lower quality embryos (16). Another study found that men with higher BPA levels were 3 to 4 times more likely to have low sperm concentration and low sperm count (17). In addition, men who worked in BPA-producing factories in China were 4.5 times more likely to report erectile dysfunction and lower overall sexual satisfaction than other men (18). However, even if such effects are noticeable, several reviews agree that more studies are needed to strengthen the evidence base (8, 19, 20, 21).

Summary: Several studies show that BPA can affect many aspects of male and female fertility.

Negative effects of BPA on babies

Most studies - but not all studies - have observed that infants born to mothers exposed to BPA at work weighed on average up to 0.2 kilograms less at birth than infants born to women who were not exposed to BPA (22, 23, 24). Children of parents exposed to BPA also tended to have a smaller distance from the anus to the genitals, once again pointing to the hormonal effects of BPA during development (25). In addition, children whose mothers had high BPA levels were more hyperactive, anxious and depressed. They were also 1.5 times more emotionally reactive and 1.1 times more aggressive (26, 27, 28). Finally, BPA exposure during early life is believed to affect the development of prostate and breast tissue in a way that increases the risk of cancer. However, although there are numerous animal studies reporting this, human studies are less clear (29, 30, 31, 32, 33, 34).

Summary: BPA exposure during early life could affect birth weight, hormonal development, behavior and cancer risk later in life.

BPA is associated with heart disease and type 2 diabetes

Human studies report a 27 to 1355 higher risk of high blood pressure in people with high BPA levels (35, 36). In addition, a study of 1,445 Americans linked high BPA levels to a 21 to 60% higher risk of diabetes (37). In another study, higher BPA levels were associated with a 68 to 130% higher risk of type 2 diabetes (38). In addition, people with the highest BPA levels had a 37% higher risk of insulin resistance, which is one of the primary factors for metabolic syndrome and type 2 diabetes (39). However, other studies found no association between BPA and these diseases (40, 41, 42).

Summary: Higher BPA levels are associated with an increased risk of type 2 diabetes, high blood pressure and heart disease.

BPA could increase the risk of obesity

Obese women may have higher BPA levels than their normal-weight counterparts (43). Several studies also report that people with the highest BPA levels are 50 to 85% more likely to be obese and 59% more likely to have a large waist circumference - although not all studies agree on this (37, 39, 44, 45, 46, 47). Interestingly, similar observations have been made in children and adolescents (48, 49). Although prenatal exposure to BPA is associated with increased weight gain in animals, this has not been conclusively confirmed in humans (50, 51).

Summary: BPA exposure is associated with an increased risk of obesity and a larger waist circumference.

BPA could cause numerous other health problems

BPA exposure may also be associated with the following health problems:

Polycystic ovary syndrome (PCOS): BPA levels in women suffering from polycystic ovary syndrome could be 465 higher than in women who do not have the condition (47).
Preterm birth: Women with higher BA levels during pregnancy have a 91% higher risk of preterm birth before 37 weeks gestation (52).
Asthma: Higher prenatal exposure to BPA is associated with a 130% higher risk of respiratory problems in children under 6 months of age. Exposure to BPA in early childhood is associated with respiratory problems later in childhood (53, 54).
Liver function: Higher BPA levels are associated with a 29% higher risk of abnormal liver enzyme levels (37).
Immune function: Higher BPA levels may contribute to poorer immune function (55).
Thyroid function: Higher BPA levels are associated with abnormal thyroid hormone levels, indicating impaired thyroid function (56, 57, 58).
Brain function: Vervet monkeys exposed to higher levels of BPA showed a decrease in connections between brain cells (59).
Summary: BPA exposure is associated with numerous other problems related to brain, liver, thyroid and immune function. However, further research is needed to confirm these findings.

How to minimize BPA exposure

Considering all the potential negative effects mentioned above, many people will want to avoid BPA. While it may be impossible to completely eliminate BPA from your life, there are some effective ways to minimize BPA exposure:

Avoid packaged foods: eat mostly fresh, whole foods. Stay away from canned foods and foods packaged in plastic containers.
Drink from glass bottles: Buy drinks in glass bottles instead of plastic bottles and use glass bottles instead of plastic bottles.
Be selective with toys: Make sure the plastic toys you buy for your children are made from BPA-free material - this is especially true for toys that children might chew or suck on.
Do not heat plastic containers or plastic packaging in the microwave: heat and store food in glass containers instead of plastic containers.
Buy baby food in powder form: some experts recommend powders instead of liquids, which may be packaged in BPA packaging, as liquids absorb more BPA from the packaging.

Conclusion

Given the current evidence, it is best to avoid exposure to BPA and other potential food toxins. Pregnant women in particular may benefit from avoiding BPA, especially during the early stages of pregnancy. For others, occasionally drinking from plastic bottles or eating canned food is probably no cause for panic. On the other hand, switching from plastic containers to BPA-free alternatives doesn't require much effort, while such a move could have a potentially big impact on your health. If you aim to eat fresh and whole foods, then you will automatically reduce your BPA exposure.