BPA and the Metabolic Process
“It’s characteristic of science that we continue to improve the methodology we use. Ours is a newer, improved method that wasn’t possible before because we didn’t have standards to measure BPA metabolites. As soon as we ingest something like BPA our body starts to work and metabolizes it. Most of what we see in urine is in metabolized form, it’s not actually BPA itself,” Patricia Hunt, study co-author and professor of molecular bioscience at Washington State University, told MedTruth.
The FDA’s method involves using an enzyme solution to convert BPA metabolites back into BPA, according to Medical News Today. The study authors noted, however, that despite the “widespread use” of this enzymatic method, the efficiency of converting metabolites back into BPA has never been assessed.
Hunt drew an analogy.
“We all use our cell phone to estimate how far we walked today, how many miles. But it’s not actually measuring how far you walked, it’s measuring the movement. So, it’s not completely accurate, as opposed to an odometer that’s actually measuring miles. It’s kind of the same thing, it’s an indirect way of measuring those metabolites,” Hunt said.
The new method, in contrast, measures both BPA and metabolites directly. Levels of exposure are very important, Hunt said, because they’re used in risk assessments.
Valid Doubts About Current Testing
Lori Hoepner, assistant professor of environmental and occupational health sciences at SUNY Downstate Health Sciences University School of Public Health, urged caution about over-interpreting the study, which involved a total of 39 individuals.
“We can’t say from just one time that this is it, everything that’s done by the CDC (Centers for Disease Control and Prevention) and the FDA is 100% inaccurate. It has to be tested a few more times and validated with more human samples,” Hoepner told MedTruth. “The take-home message is that this is casting doubt – and valid doubt – on the methods that are being used by governmental agencies.”
“The question is, ‘Where do we go from here?’ How do we determine the use of a more direct measurement to be better? How do we go about changing the current standards for determining BPA exposure in humans?” Hoepner said.
Why Is BPA Still FDA Approved?
Despite banning BPA in baby bottles, sippy cups and infant formula packaging in 2012, the FDA asserts that current BPA exposure levels are safe.
“Based on FDA’s ongoing safety review of scientific evidence, the available information continues to support the safety of BPA for the currently approved uses in food containers and packaging,” the FDA website states.
Hunt said that there’s been “no response at all” from the FDA regarding the study.
“I would like to think that they’re busy working on it, that they’re repeating our studies and validating their own approaches and that we will hear from them, yes. I’ve been surprised that they have not responded,” she said.
The FDA responded to MedTruth’s request for comment on the study with the following statement:
“The FDA bases our regulatory decisions on sound science and we remain dedicated to reviewing and evaluating all relevant scientific evidence as part of our commitment to ensure the safety of foods, food additives, and food packaging materials.
One area that has been of significant interest to consumers is the use of Bisphenol A (BPA) in food packaging. BPA is authorized for use in the manufacture of polycarbonate plastics and epoxy resins used in some food and beverage can linings. The agency has considered and evaluated the scientific evidence on the use of BPA in food packaging applications. Based on the totality of the currently available data we continue to conclude that BPA is safe for the presently authorized uses in food containers and packaging.
It would be inaccurate to state that the FDA’s assessment of the safety of BPA is based only on one type of analysis or scientific study. It is important to note that the FDA’s research and findings on BPA are based on a thorough analysis of the totality of scientific data on BPA. This includes reviewing and studying potential dose-related effects of BPA, evaluating potential sources of BPA, and evaluating methods for analyzing exposure to BPA. For example, the FDA conducted an updated dietary intake assessment for BPA in 2014, which combined measured levels in many common foods with food frequency and portion size estimates, in addition to biomonitoring estimates from the CDC’s the National Health and Nutrition Examination Survey (NHANES) data.”
Are BPA Free Substitutes Worse?
BPA is an acronym for bisphenol-A. Substitute chemicals for BPA include BPF (bisphenol-F) and BPS (biphenol-S), which are nearly identical to BPA, with perhaps just a few molecules of difference.
“There’s studies comparing different bisphenols that find similar effects to BPA, in some cases even worse results. They’re no guarantee of a safer product,” Hunt said. “Although it’s a great marketing tool, because consumers reach for that ‘BPA Free’ and they’re probably willing to pay more.”
According to Hunt, bisphenol replacements are proliferating to the point that it’s become virtually impossible to track their individual exposure levels or health impacts.
“These new replacement bisphenols have come on the market really rapidly. BPS and BPF are the most common ones but there are many more. So, if they were to mount a big risk assessment of each of these chemicals this would be years and years of work,” Hunt said. “It’s overwhelming our regulatory system and there’s no way to keep pace with the emergence of these chemicals.”
How to Protect Yourself From BPA Exposure
“Consumers need to think about plastics and these types of products differently. Buy yourself a new water bottle. Stop thinking about plastic food containers as permanent items, they’re not. If you see signs of wear and tear on them, throw them out because they’re starting to leach the chemicals. Don’t put them in the microwave or the dishwasher, because heat is an invitation for chemicals to migrate out,” Hunt said.
As if that weren’t enough to worry about, bisphenols are also found in children’s toys, home electronics, CDs and DVDs, toiletries, feminine hygiene products, sporting goods, dental filling sealants and medical devices. But it’s exposure through food packaging that’s the most concerning, according to Hoepner.