What is bisphenol A (BPA), how does it affect the body, and what can we do to avoid it?
Bisphenol A (BPA) is a chemical primarily used to make plastics clear and nearly shatter-proof. It can be found in a variety of consumer goods such as baby and water bottles, sports equipment, CDs and DVDs, and also in the inner coatings of many food and beverage cans and thermal paper used for sales receipts.
We are primarily exposed to BPA through our ingestion of contaminated food and water. It can leach from the food containers and cans, especially when they’re cleaned with harsh detergents or are heated to high temperatures. Older water pipes are coated with BPA and we regularly handle many types of products that contain it as well, such as electrical equipment, sports equipment, paints, and adhesives.
What’s the problem?
What kind of effects can it have on the body? Well, let’s jump in…
Animal research has demonstrated its ability to cause a wide variety of negative health effects even at low levels of exposure, such as:
- Reduced maternal care and nursing behavior.
- A reduction in sexual interest in males.
- Early onset of sexual maturation in females.
- Decreased testosterone levels in males.
- Lowered sperm count and fertility.
- Impaired immune function.
- Changes in behavior such as hyperactivity and increased aggressiveness, impaired learning.
- And more.
In humans, BPA has been positively associated with an increased risk of ovarian dysfunction and obesity, cardiovascular disease, diabetes, and prostate cancer, as well as an alteration of gender differentiation in the brain.
Unfortunately, exposure to BPA is widespread here in the States. According to research published by the Centers for Disease Control (CDC) in 2005, 95% of people in the United States have measurable BPA levels in their urine.
Scientists are particularly concerned about BPA exposure in pregnant women. According to a study conducted by the University of California and published in 2011 analyzed data for 163 chemicals in 268 pregnant women and found that nearly all carried multiple chemicals, including some banned since the 1970s.
ScienceDaily reported on this study and interviewed the lead author. Here’s an excerpt (emphasis added):
“It was surprising and concerning to find so many chemicals in pregnant women without fully knowing the implications for pregnancy,” said lead author Tracey Woodruff, PhD, MPH, director of the UCSF Program on Reproductive Health and the Environment.
“Several of these chemicals in pregnant women were at the same concentrations that have been associated with negative effects in children from other studies. In addition, exposure to multiple chemicals that can increase the risk of the same adverse health outcome can have a greater impact than exposure to just one chemical,” said Woodruff, an associate professor in the UCSF Department of Obstetrics and Gynecology and Reproductive Sciences.
Exposure to chemicals during fetal development has been shown to increase the risk of adverse health consequences, including preterm birth and birth defects, childhood morbidity, and adult disease and mortality according to the research team. In addition, chemicals can cross the placenta and enter the fetus, and in other studies, a number of chemicals measured in maternal urine and serum have been found in amniotic fluid, cord blood and meconium, they state.
The mounting evidence against the use of BPA is what led the Canadian government to ban BPA as a toxic substance in 2010. In the same year, the United States Food and Drug Administration didn’t go so far, but did warn of possible hazards to fetuses, infants, and young children.
Despite the weight of evidence mounting against it, and the many appeals to the precautionary principle by people in the scientific community, the debate over the ultimate safety of current levels of BPA exposure remains controversial.
According to many industry-funded studies, like the often-cited research the American Plastics Council paid the Harvard Center for Risk Analysis to conduct, exposure levels are too low to be a real cause for concern. Less biased studies, such as those conducted by governments, disagree, however.
Researchers at the University of Missouri published a fantastic review of BPA literature in 2005, and here’s what they had to say on the matter (emphasis added):
“As of the end of 2004, we are aware of 21 studies that report no harm in response to low doses of BPA. Source of funding is highly correlated with positive or negative findings in published articles. For government-funded published studies, 94 of 104 (90%) report significant effects at doses of BPA < 50 mg/kg/day. No industry-funded studies (0 of 11, or 0%) report significant effects at these same doses. It is thus reasonable to pose two questions: a) Are government-funded scientists under real or perceived pressure to find or publish only data suggesting adverse outcomes? B) Are industry-funded scientists under real or perceived pressure to find or publish only data suggesting negative outcomes?”
These scientists aren’t alone in their views—even the National Toxicology Program agrees.At the request of the U.S. EPA, the NTP conducted an extensive review of literature in 2000 and were highly critical of several industry-funded studies commonly cited to dismiss BPA concerns.
So, with the scales of evidence tipping against BPA, it seems sensible for us to reduce exposure as much as possible.
Most educated consumers are taking simple measures to reduce their exposure to BPA, but many are still unaware that it’s only one of several forms of bisphenols commonly used in production.
Unethical manufacturers are substituting these lesser known forms for BPA so they can claim their products are “BPA free.”
Researchers from the University at Albany put it plainly in a study published in 2013:
“As the concern over the safety of bisphenol A (BPA) continues to grow, this compound is gradually being replaced, in industrial applications, with compounds such as bisphenol F (BPF) and bisphenol S (BPS).”
Other forms of bisphenols like BPS and BPF aren’t as well know and researched as BPA, but studies have already shown that they cause the same effects in the body. One study even showed that BPS isn’t as biodegradable as BPA, and “might be persistent and become an ecological burden.”
As a part of the University at Albany study, researchers tested a wide variety of foodstuffs for other forms of bisphenols, including beverages, dairy products, fat and oils, fish and seafood, cereals, meat and meat products, fruits, vegetables, and others.
The result: bisphenols were found in the majority (75%) of the food samples. In the vegetables category, a sample of mustard (dressing) and ginger contained the highest concentrations of BPF. Canned foods contained more bisphenols than foods sold in glass, paper, or plastic containers.
Unfortunately, we just can’t trust “BPA free” labels. To be sure, it requires a little research on the companies and their products. Better still is to just avoid the common sources of bisphenols altogether.
There are several simple things you can do to reduce your exposure to all forms of bisphenols.
- Before you buy anything stored in a plastic, look for the recycling sign with a number in it. If the number is 1, 2, 4, 5 or 6, it is less likely to contain bisphenols. If it’s a 7, however, it likely does, and you shouldn’t buy it. Containers marked with a 3 can also contain bisphenols, and should be avoided.
- Use glass containers to store anything that you will be eating or drinking. This is especially important for pregnant women and babies, as the negative effects of bisphenols can be more serious for them.
- Don’t microwave food in plastic containers. If you’re going to store your food in plastic containers, don’t cook your food in them. This applies to any food that comes pre-packaged in microwavable containers as well–the types of plastic used in many of them contains bisphenols, and heating it up causes the chemical to leach into the food.
- If you don’t need a receipt, leave it. In fact, ask the cashier to not even print it. If you do need it, ask him or her to put it in the bag. If you have to handle receipts for your work or bookkeeping, wash your hands well after.
- Avoid cheap bottled water. Go for filtered tap water instead (reverse osmosis filters are great for home use).
- Avoid plastic utensils. Use metal instead.
- Use a French press or ceramic drip to make coffee instead of a plastic coffee maker. These can leach quite a bit of bisphenols into your beverages.
- Eat fewer canned foods. Opt for fresh or frozen fruits and vegetables, and for foods like sauces, pasta, soups, and juices, choose those that are packaged in glass or cardboard containers.
While it’s impossible to bring your exposure to bisphenols down to zero, you can greatly reduce your exposure by taking the above actions.