BPA Is Everywhere. It’s Safe?
Bisphenol A, or BPA, is a chemical found in plastics, including food packaging, that can interfere with our cells. Are we exposed enough to BPA to harm us? And should you be wary of alternative products with BPA-free labels? Let’s just say … it’s tricky.
What is BPA?
Remember when Nalgene bottles were fashionable ? In the early 2000s, we did not have jet bags, but we did have hard plastic water bottles that were made from the same material found in bulletproof glass . They didn’t break when you dropped them, and they didn’t taste plastic in the water. This was the future. The future was good.
These bottles were made from a durable plastic called polycarbonate, or more accurately, bisphenol A polycarbonate. This is what bisphenol A or BPA looks like:
If you want to make polycarbonate plastic , you need some BPA, another molecule called phosgene (it provides the “carbonate” part), and a few other chemicals to combine them into a chain that goes BPA-carbonate-BPA-carbonate. -BPA-carbonate. All plastics or polymers such chains are: polyethylene – a chain ethylenes , polystyrene – chain styrenes and so on. This is what polycarbonate from BPA plastic looks like (repeat in parentheses):
Nothing lasts forever, not even heavy-duty plastic. Over time, the polymers break down and pieces of them can break off the chain. BPA in chains can’t hurt you, but people are worried about the building blocks of BPA that work for free. Heat accelerates the breakdown process , so anything that’s been heated in the microwave or left in the sun is more likely to contain BPA, which people are worried about.
Here’s the main reason people worry: BPA is in the form of estradiol , a type of estrogen. The similarity is close enough to actually match the estrogen receptors in our cell nuclei . These receptors cause changes in how cells read instructions from DNA. Too much estrogen in the wrong place or at the wrong time can interfere with embryonic development or affect the growth of tumors .
Is BPA harmful?
If someone hands you a glass of estrogen, you won’t drink it. But a sip of water from a polycarbonate bottle is far from the same thing. First, very little BPA leaches out of the bottle into your water; second, BPA binds 10,000 times weaker than estrogen .
The question is not whether BPA can act like estrogen – we know that. The question is, is the amount that leaches out of your water bottle (and canned food liners and thermal paper store receipts) enough to be harmful. Some scientists and environmental groups say this is the case; others, including those associated with the plastics industry, say this is not the case.
Here’s a quick overview of who says what:
- In 2010, the World Health Organization concluded that data range from “no health problems” in some cases to paucity of data in others.
- In 2014, the US Food and Drug Administration wrote that “there is sufficient safety margin for bisphenol A at current exposure levels in food contact” (in other words, can liners and other packaging) and that “ BPA is safe at current levels. found in food “.
- In January 2015, the European Food Safety Authority concluded that “there is no health concern for any age group due to food exposure and low health hazards due to cumulative exposure.”
- The Endocrine Society wrote in a 2015 review that recent research “removes any doubt that [endocrine disruptors such as BPA] are contributing to an increased burden of chronic disease associated with obesity, diabetes, reproductive health, thyroid, cancer, and also neuroendocrine functions and functions of nervous development ”.
These conclusions hide mountains of contradictions. There is no conclusive, conclusive evidence that BPA is harmful, but it’s hard to know what to believe when the best research is industry funded and “independent” research is small and cannot be replicated .
Jones’s mother discovered that at least one company was withholding the results of its tests , and the Environmental Protection Task Force accused the US government of relying too heavily on industry-funded research. The sad truth is that research findings tend to align with the interests of those who funded them . Sometimes this is due to unconscious bias, and sometimes due to deliberate choices in research design and reporting. For example, critics say the rats used in many animal studies of bisphenol A do not respond strongly to estrogen.
This is just one of the criticisms in a 2005 Environmental Health Perspectives article arguing the toxicity of bisphenol A at low doses, and decades of research have completely overlooked this fact. For most substances, there is a direct dose-response relationship: for example, the more alcohol you drink, the more you drink. To argue that BPA is dangerous at low levels, researchers must argue that BPA does not follow this rule. Statistician Patrick McKnight reviewed the idea in Sense About Statistics and found that studies on the effects of low doses were chaotic. Low doses may be dangerous, but the available data are not conclusive. We still need to do more research.
This is the conclusion that almost all research comes to, for or against: BPA research is not enough. More precisely, there has been a lot of research done, but they usually do not answer the questions we are most interested in. For example, there is very little research on the effects of BPA on real living people. Much of the work involved laboratory dishes with cages or exposure to rats and fish.
And yet, since we know about bisphenol A, we know even less about the chemicals in plastics that do not contain BPA. One BPA substitute is bisphenol S , which also appears to be endocrine disruptors. A study of over 500 plastic products published in the journal Environmental Health Perspectives and conducted by a testing lab that made enemies of the plastics industry found that “almost all” tested plastic products showed estrogenic activity, including those labeled as “BPA-free. … “
The EPA reviewed a list of possible BPA replacements in thermal paper (commonly used in cash register receipts) and found no “clearly safer alternatives.” In their detailed comparison chart, BPA alone filled most of the hazard ratings; the rest were filled in with footnote ratings.
If you want to avoid taking bisphenol A
I hate being an alarmist. You probably don’t need to avoid using BPA. Chances are good that low doses are not a problem, but we do not have sufficient evidence to be completely certain. There is nothing wrong with replacing plastic with other materials, especially if you find yourself preferring their looks or functionality.
If you avoid BPA-containing plastics as a precautionary measure, you should probably avoid other plastics as well. After all, new chemicals do not have to be recognized as safe before they enter the market. So if the bottle says “BPA Free,” it means it is missing the chemical that was studied and instead contains a new chemical that we don’t know anything about. Maybe it’s better, maybe worse. If you are looking to avoid plastic surgery with possible endocrine disruptors, here are some strategies that can help:
- Choose non-plastics like glass and stainless steel . These options are available, although usually more expensive, for things like food containers and water bottles. Milk from this mason jar trend while you still can!
- Avoid heating plastic containers in a microwave oven or otherwise exposing them to stress such as heat and sunlight. Even if you use plastic to store your food, you can put the food in a bowl in the microwave and be sure to wash the plastic container by hand rather than putting it in the dishwasher.
- Avoid canned food as the cans are coated with epoxy, which usually contains BPA. Fresh or frozen food is not such a concern. Tetra’s packaging, these square containers that look like juice boxes, use plastic that is not (yet) associated with estrogenic activity.
- Don’t lick your checks . Yes, you are laughing, but you are not a six month old baby. At that age, my kids thought the recipes were delicious. Rough handling of the check with dry hands does not raise the levels of BPA in your body , even if it does contain the chemical, so if that’s all you do with it, it’s probably okay.
Some people go to great lengths to avoid plastic entering their lives. If this seems overkill, consider using these tips occasionally. For example, I store leftover food in glass containers at home, although I still use plastic when putting together my take-out lunch. These precautions may seem silly in 50 years, but it seems right now.