An article in The Washington Post discussed a study about the dangers of BPA, bloggers are concerned about it, soup companies are eliminating it, moms are taking plastics out of their homes, and an article posted on the website foodconsumer.org discussed the FDA’s denial of a request to ban BPA in products manufactured in the United States. Dr. Bruce Chassy concludes that while infinitesimal amounts of BPA do enter the food or beverage, it's all about the quantity of exposure that matters.
To better understand the many questions about BPA, we enlisted the help of food system expert Dr. Bruce Chassy.
Dr. Bruce Chassy – University of Illinois at Champaign/Urbana
Can you help explain what Bisphenol A (BPA) is and how it may affect human health?
Chassy: "BPA is a chemical that is added to plastic containers and plastic can liners to help keep products fresh and to inhibit corrosion. It remains in the plastic; however, infinitesimal amounts do enter the food or beverage. There is no point speculating about what BPA might do if it were present in our diets at much higher levels because we could do the same thing with any normally occurring food component. Even something as simple as salt can be deadly if we consume too much. There are numerous published scientific articles that demonstrate that much higher levels of BPA than we are exposed to can produce a variety of very undesirable health outcomes. No doubt about that."
"Claims regarding BPA’s correlation with diseases including breast cancer, heart disease and diabetes have been examined numerous times by regulatory agencies in several countries, and they have all concluded that no health threat can be associated with BPA."
The article in The Washington Post states that many experts believe plastic food packaging is a major source of BPA. With consumers becoming more health-conscious and aware of how their food is produced, should they be concerned about the amount of BPA in plastic food packaging?
Chassy: "No, regulatory agencies around the globe have found it to be safe to consume in the small amounts currently present in our diets."
How does the FDA determine whether a chemical is safe for use in food packaging?
Chassy: "It's complicated. FDA uses a variety of tests. They look carefully at the amount of a chemical in our diets, how much we absorb, where it goes in our bodies, and how quickly we metabolize and excrete it in order to determine what our exposure to the compound will be. They study the effect of the compound in at least two unrelated animal species – in the case of BPA many more species have been studied. They look at population data comparing health outcomes in populations that are exposed to BPA and those that are not, although these kinds of studies can only point to associations and cannot prove them.No matter how you look at it, BPA poses no threat in the amounts we encounter in the real world."
Canada declared BPA a toxic substance in 2010, and is the only country to date that has done so. Should other countries follow suit?
Chassy: "If you read the Canadian decision carefully, they did not declare BPA to be unsafe at the levels currently found in foods and beverages based on evidence of actual adverse or harmful effects. What they did was say that as a precautionary measure they would move to restrict intake by infants and children by declaring BPA to be a toxic chemical, which allowed regulators to place restrictions on it. Toxicologists and regulators in other countries do not agree with Canada and their action remains a non-science-based outlier among nations. It is worth noting again that any chemical can be toxic, so any chemical can be banned, based on that logic."
All in all, what is your recommendation for consumers regarding food consumption from packaging containing BPA?
Chassy: "All chemicals, both naturally occurring and synthetic, can be poisonous if we consume enough of them, but FDA, other regulatory agencies, and research toxicologists who have published in scientific literature have all concluded that the amounts that we encounter in our diets pose no threat of harm to us. More than 40 years of safe use of BPA attest to this."
What happens to BPA in our bodies?
Chassy: "Research has shown that BPA is rapidly metabolized or detoxified by our bodies and it is also quickly excreted. It does not reach high levels or accumulate in blood or tissue.This is one of the primary reasons BPA poses little risk to consumers. Studies that claim BPA is toxic almost always expose tissues or cells to BPA at high levels and for times that would never occur in the real world. My advice to consumers is to concentrate their attention on real risks that do real harm. Eating a balanced healthy diet and not over-eating are the two most important things that a consumer can do to ensure good health and long life."
You stated that it shouldn’t be of concern, but if chemicals at any level can be toxic, shouldn’t we try to avoid them if we can? Are there any tips we can provide to consumers regarding safe handling or ways to avoid BPA if they aren’t convinced (for example, about using clear plastic wrap when reheating foods)?
Chassy: "There is widespread confusion about toxic chemicals and whether we should try to avoid them. I think this starts with a basic misunderstanding of what toxic really means, and this is compounded by a widely-held belief that man-made, or synthetic, chemicals are somehow inherently more toxic than those found in nature. It’s worth taking a moment to examine these two points.
"Almost all chemicals that we consume are toxic if we consume enough of them. This includes most all of the thousands of chemicals that comprise the food we eat. For example, vitamins A and D are both extremely toxic, toxic enough to kill, if we consume too much of them. It would be a fruitless endeavor to try to avoid anything that was toxic – there would be nothing we could eat or drink. If one wants to avoid toxic effects, the trick is to not consume harmful amounts of the thousands of potentially toxic chemicals to which we are exposed on a daily basis.
"Are man-made chemicals inherently more dangerous? The evidence is that they are not any more toxic than very toxic compounds that occur naturally in our food – strychnine, botulism, and mushroom poisoning are examples of toxic natural compounds. Some people believe that our bodies can’t cope with compounds that are not found in nature. Toxicologists have shown that our bodies’ natural defenses can cope with man-made as well as natural toxic compounds, to a point. And that’s the secret – avoiding consumption of so much of a compound that it is toxic. And that’s what toxicologists do. They determine how much is safe to consume over a lifetime of consumption. In the case of BPA, toxicologists have found that the amounts found in our food and beverages are far below those that will do harm.
"The systems our bodies use to detoxify and eliminate foreign chemicals evolved over hundreds of millions of years to give us broad protection against the literally millions of potentially toxic natural compounds to which we are exposed throughout life. The system is so comprehensive that only a very few chemicals – either natural or man-made – escape detoxification and excretion. We usually call such chemicals “poisons.” Many of the most toxic poisons are natural. Human-made, synthetic, or artificial chemicals are no more or less toxic than naturally-occurring chemicals. EPA and FDA regulators do not approve new chemicals unless studies show that they can be safely processed by our bodies at least at levels 100-fold higher than those to which we would be exposed in everyday use."
I’ve heard that leaving plastic water bottles in your car in warm weather causes the plastic to break down and the chemicals in the bottle to leach into the water. I’ve also heard that clear plastic wrap leaches chemicals into foods if they are touching during reheating. Can you verify this?
Chassy: "It is the dose that makes the poison. It’s true that infinitesimal amounts of BPA may be leached from materials that contain them when they are warmed, but years of study have shown that the amounts released pose no threat to human health. I should note that some plastics do not contain BPA, and in response to public concerns about BPA more and more manufacturers have discontinued using BPA in their products. Some products are labeled as being BPA-free."