Toxic Chemical Whack-A-Mole and the BPA

It’s a common sight: a baby drinking out of a plastic bottle, a toddler drinking from a plastic sippy cup or a fruit squeeze pack. Most parents think nothing of it. That is especially true now that these bottles, cups, and packaging are labeled BPA-Free, after advocacy groups fought for years to rid baby and kids’ products of the notorious endocrine-disrupting chemical (EDC) bisphenol A, which is ubiquitous in plastics, metal can liners, and a range of food packaging. 

You’ll see the label displayed prominently on thousands of products on grocery store shelves. In the early 2000s “mom groups” were especially vocal about keeping the chemical out of children’s foods because of the damage it appears to do to the developing brain and reproductive and metabolic systems. And in this case, advocates achieved a seeming victory when the Food and Drug Administration announced in 2012 that industry could no longer use the chemical in baby bottles and children’s sippy cups. 

So it’s all good, right? Well… no.

The industry replaced the chemical with bisphenol S—a related chemical compound that not surprisingly has the same kind of deleterious effects in the bodies of children and adults alike. 

“It’s an empty victory. I feel bad saying that because there was really strong work on the part of advocacy groups that fought to get rid of BPA, but they would be horrified to know that their actions replaced one estrogenic chemical with another, and yet it became a marketing tool,” said Laura Vandenberg, an EDC researcher who teaches at the University of Massachusetts. Since then, “BPA-free” has been used as a marketing tactic, while the food and chemical industries sells us another environmental chemical as progress. We didn’t rid our foods of a toxic chemical, we just replaced it with a different one. 

Photo by tanvi sharma on Unsplash

What is BPA?

BPA, one of the most common and well-researched endocrine disruptors, is found in much of our food and beverage packaging— including water bottles, water coolers, soda cans and bottles, and food cans used for soups, beans, tomatoes, tuna, and sardines, among hundreds of other foods. 

In more than one thousand studies in animals and one hundred in humans, the chemical, which is structurally similar to the natural hormone estrogen, shows adverse health effects, ranging from metabolic disruption and increased risk of obesity to infertility, altered brain development, and certain cancers, such as breast and prostate.  BPA leaches quite readily into food from plastics and can linings—the Centers for Disease Control and Prevention estimate that 99 percent of Americans have detectable levels of it in our blood. 

Frederick vom Saal, Curators’ Distinguished Professor and professor emeritus of biological sciences at the University of Missouri, told me that researchers are seeing effects from BPA at extremely low doses. In his studies, he has seen effects at two picograms, that is, parts per trillion (one trillionth of a gram), in animal studies.

“That is ten to one hundred times lower than what the U.S. Food and Drug Administration and the National Toxicology program say you would expect to find in humans. And it’s a thousand times lower than what is thought to be present in human babies,” he said. “We’re down to a molecule, a cell that can alter things.”

In the late 1990s and early 2000s, advocacy groups demanded that this estrogenic compound be removed from baby bottles and child “sippy cups.” Now many baby bottles and other packaging materials contain bisphenol S, or BPS, a chemical with a similar chemical structure—and not surprisingly—related negative health consequences. But manufacturers claim “BPA-Free” on products, giving the illusion that harmful chemicals are no longer present. 

Vandenberg, assistant professor of environmental health sciences at the University of Massachusetts and an EDC researcher, said that while there is some indication that BPA levels are going down in the general population, BPS levels are going up. Like DDT, both BPA and BPS are so similar to natural estrogen that they can bind to estrogen receptors in the body.

Vandenberg explained it like a key and a lock: estrogen is the key and the receptor is the lock. These estrogenic chemicals fit in the receptors for natural estrogen and then induce biological changes in our bodies. Once the chemicals bind to the receptors, they go to spots on the DNA where it binds again and turns certain genes on or off, creating an epigenetic effect. This is especially harmful to fetuses. Vandenberg has found that female rodents exposed to BPA in the womb exhibit risk factors for breast cancer and as they age are developing full-blown carcinomas in the mammary gland. Vandenberg also sees increased risk factors for cancer in the mammary glands of male rodents exposed in the womb.

More Problems for BPA

BPA is problematic in other ways—not just as an estrogenic chemical. “We’ve been focusing on BPA as an estrogen, but in addition to being an estrogen, it also turns out to be very promiscuous in interfering with all kinds of biological process,” vom Saal said.

One biological process that he is most concerned about is the regulation and development of fat cells. Vom Saal and his colleagues found that low-dose fetal exposure in mice led to an increase in body weight, liver weight, and abdominal fat mass when those mice became adult males. And in 2016 another group of researchers found that low-dose exposure to BPA in rodents during the developmental period caused fat accumulation and promoted inflammation resulting in decreased insulin sensitivity in fat cells. “There is nothing about BPA that would have predicted it would be like your ultimate terrorist molecule. This is just a nightmare molecule that should not be in contact with our food,” vom Saal said.

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For more on these issues see my book, Formerly Known As Food, chapters six and seven.