Tag Archives: Endocrinology

I confess: When it comes to toxic chemicals, I trusted the FDA too long

Bisphenol A has been creating a dilemma for me since I first heard that it could disrupt normal hormone function in people and animals.

BPA chemical structure

BPA, as the chemical is known, is produced in large quantities, sold around the world, and used in many products — including food cans, plastic bottles, toys and even sales receipts you might be handed at a retail store. Exposure is widespread, with detectable levels of BPA found in at least 93 percent of Americans who are 6 years old or older.

As part of my daily routine, I check out research reports on a variety of environmental and water-related subjects. It seems like there is a never-ending stream of reports, numbering in the thousands, that continue to find problems with even low exposures to BPA.

And there’s the root of my dilemma. The federal Food and Drug Administration, which is responsible for protecting us from tainted food and drink, keeps telling us that BPA is safe at current levels of exposure. Check out the statement from the FDA’s Deputy Commissioner Stephen Ostroff.

In 2008, I informed readers (Water Ways, April 11, 2008) that I was searching for and throwing out my drinking-water bottles likely to contain BPA. My actions were based on alarms raised by researchers, including those at the National Institute of Environmental Health Sciences. For years, I’ve wanted to provide firm, up-to-date advice about BPA, but I guess I’ve been unduly stymied by my faith in the FDA.

With those thoughts in mind, I called Patricia Hunt, a researcher at Washington State University’s Center for Reproductive Biology. Pat has studied the science of BPA for many years. One of the problems leading to the FDA’s position, she told me, is that government officials don’t want to give up the long-held toxicological approach to regulating chemicals.

Under the old-fashioned system, the more exposure one receives to a harmful chemical, the worse the health problems are likely to be. So the FDA determines a safe level and expects everyone to comply. But that system does not always work for hormones or for chemicals that act like hormones — such as BPA.

When would a higher dose of a chemical produce a lesser effect? Hormones often work in partnership with a receptor — like a key in a lock — to produce a biological response. A chemical that mimics a hormone may produce an inappropriate and even harmful biological response. Starting at extremely low doses, things may get worse as the dose is increased. But at some level the hormone receptors may become saturated, causing the biological effect to diminish as doses continue to increase.

This is just an example, but hormones and related synthetic chemicals may not react in the same way. Their dose-response curve may even be different for different organs of the body.

That is one problem with the toxicological system under which the government operates, according to Pat Hunt and two other researchers who wrote an opinion piece in the journal “Nature Reviews: Endocrinology.” In the article, she and the other authors praise an extensive — and expensive — research project launched by the federal government to identify the harmful effects of BPA. The project goes by the hopeful name CLARITY, which stands for Consortium Linking Academic and Regulatory Insights on Toxicity of Bisphenol A.

The project was insightful, they argue, but only if FDA officials are willing to look at the limitations of the study’s design and avoid rejecting findings from academic researchers that might not fit an expected pattern.

“Although, ideally, a consensus between the approaches should be possible,” their article states, “differences in research culture made the CLARITY effort akin to expecting a group of folk and punk rock musicians to pick
up their instruments and play together 
in harmony.”

Low-dose effects were found in the data of many studies and should have set off alarm bells, they say. Exposure for animals in the developmental stages are particularly concerning, and the effects may not show up until the animal becomes a sexually mature adult.

“Taken together, these data suggest that low-dose BPA exposure induces subtle developmental changes that act to impair the endocrine, reproductive, neurobiological and immune system of adult rats,” states the article, which goes into far more detail than I can cover here.

BPA has gotten a lot of public attention, which has encouraged manufacturers to replace BPA with other chemicals and advertise their products as “BPA free.” The problem is that the substitutes may be just as bad or worse, according to researchers. In fact, some of the substitutes have been banned in Washington state, so companies are off to the next replacement chemicals.

The problem is that the modern world is filled with chemicals that have not been adequately tested for safety, Pat told me. Ideally, the chemicals would have been tested before they went on the market, but that’s not how things were done in the past. Now the government is challenged to identify chemicals on the market that cause health problems even while people are being continually exposed.

The current Trump administration seems to have little interest in this topic, even though a new federal law signed in 2016 by former President Barack Obama was designed to address the problem. I wrote about this for the Encyclopedia of Puget Sound in 2016, along with a story about “rogue chemicals” in the environment.

“A lot of us feel that, to come up with a safe level of exposure, some of these chemicals should not even be in the products they are in,” Pat said.

In explaining this difficult problem to the parents of young children, she sometimes holds up a package of birth-control pills and asks, “How much of this should I be allowed to give your child?” Parents don’t want their child to have any, she said, yet we live in a world in which children are ingesting such chemicals, like it or not.

I had thought that the FDA had at least banned BPA in baby bottles, sippy cups and other products that could increase exposure to children at a critical time of their development. But that was not the case. The agency had simply “abandoned” its approval of such uses, because companies had changed their products voluntarily.

“An amendment of the food additive regulations based on abandonment is not based on safety but is based on the fact that the regulatory authorization is no longer necessary,” the FDA emphasized in a fact sheet.

In other words, the FDA has never changed its stance on BPA. Meanwhile, a number of states have taken steps to protect children. Some — like Washington — have gone further to protect more of the population. But others have done nothing.

So what can people do about BPA and other chemical concerns?

“You can ask for what you want,” Pat said. “I always tell consumers that they can vote with their pocketbooks.”

Personally, I have cut back on canned foods, because BPA is used to reduce metal corrosion, although it can leach into foods — especially acidic foods. I no longer heat food or drinks in plastic containers, and I’m slowly converting to glass for storing food on the shelf and in my refrigerator.

For more information and tips about what you can do, check out these sources: