How does bisphenol A affect health?
Products that contain BPA include water bottles, baby bottles, dental fillings and sealants, dental devices, medical devices, eyeglass lenses, DVDs and CDs, household electronic items, and sports equipment.
It can also be found in epoxy resins that are used to coat the inside of food and drinks cans.
Large amounts of BPA are produced each year. It leaches into food and water supplies, and humans are widely exposed to it.
Here are some key points about BPA. More detail is in the main article.
- BPA is present all around us in the environment and in manufactured products.
- Research has linked exposure to fertility problems, male impotence, heart disease and other conditions.
- Some reports say that current levels of BPA are low and not a danger to humans.
- Tips for avoiding exposure include breastfeeding infants and not buying food in plastic packaging.
Bisphenol A is found in the hard plastic bottles many people use every day.
BPA is an endocrine disruptor.
It can imitate the body's hormones, and it can interfere with the production, secretion, transport, action, function, and elimination of natural hormones.
BPA can behave in a similar way to estrogen and other hormones in the human body.
Infants and young children are said to be especially sensitive to the effects of BPA.
Research suggests it can impact human health in various ways.
In 2013, scientists from Brigham and Women's Hospital published findings showing that BPA exposure can affect egg maturation in humans.
A review of previous studies, published in 2015, found evidence that BPA can interfere with endocrine function involving the hypothalamus and the pituitary gland.
The authors add: "The detrimental effects on reproduction may be lifelong and transgenerational."
Male impotence may be affected, according to a study that looked at the effect of men's exposure to BPA at work. Findings indicated that high-level exposure may increase the risk of erectile dysfunction and problems with sexual desire and ejaculation.
Type 2 diabetes and body weight
Fetal brain development
Environmental exposure to BPA has the potential to affect the developing brain during gestation, according to research.
Breast and prostate cancer
Scientists believe BPA, with its estrogen-like behavior, could increase the risk of breast, prostate, and other cancers in people who were exposed to it in the womb.
In 2015, a group of researchers concluded that "Fetal exposure to BPA could lead to "long-lasting" effects on the carcinogenesis of certain organs," potentially leading to the development of hormone-related cancers.
Public authorities set BPA safety levels, but concerns remain about degrees of exposure.
Dental sealants can also contain Bisphenol A. Be sure to speak to a dentist before application of the sealant.
One study by the Centers for Disease Control and Prevention (CDC) found BPA in nearly all human urine samples, suggesting that exposure is widespread across the United States (U.S.).
The CDC note that people are commonly exposed to low levels of BPA when they consume food or water that has been stored in containers made with the chemical.
Children may also be exposed by touching items that are made with BPA and then putting their hands in their mouth, or by putting their mouth on the item.
Other means of exposure include:
- having dental sealants that contain BPA
- working in places that manufacture products with BPA in them
- using harsh detergents, high-temperature liquids, or products that contain acidic liquids to clean containers
Thermal paper and carbonless paper may also contain varying levels of BPA, which gets onto the hands and fingers. Thermal paper is commonly used in movie theater tickets and labels.
BPA probably enters the system when the fingers are placed in the mouth, rather than through the skin.
A study of 77 Harvard College students found one week of drinking water from polycarbonate bottles increased the levels of BPA in by two-thirds. This suggests that regular consumption of water from such bottles significantly increases exposure to BPA.
BPA is used in infant's feeding bottles, so breast-feeding an infant is likely to reduce levels of BPA exposure.
How serious is the risk?
In August 2010, a report by the National Toxicology Program concluded that current levels of BPA raise:
- some concern about the effect on the brain, on behavior, and on the prostate gland in fetuses, infants, and children
- minimal concern about the effect on the mammary gland and early puberty
- negligible concern that BPA exposure will lead to fetal abnormalities, low birth weight, and reproductive problems
While these sources of potential exposure are recognized, a report about the hazards of BPA for the World Health Organization (WHO), points out that exposure rates in investigations tend to be higher than those estimated to exist in most environments.
The United States (U.S.) Food and Drug Administration (FDA) continues to support the use of BPA in current food packaging, because the amount that leaches into food is small.
It is difficult to avoid BPA because it is so prevalent in the environment, but some tips can help to minimize exposure:
- check for a BPA-free label on foods and packaging
- buy and store foods in glass jars, not plastic
- use fresh, frozen, or dried products, not canned
- avoid microwaving foods in plastic containers
- do not wash plastic containers in the dishwasher or use harsh detergents on them
- choose wooden toys instead of plastic
- breast feed infants as far as possible, instead of bottle feeding
One study has suggested that, after just 3 days of eating a fresh food diet with no products taken from a can or plastic packaging, the levels of BPA in participants' bodies fell significantly.