Does BPA Really Cause Hormone Disruption?
Some have created doubt that current levels of human exposure to bisphenol A (BPA) is disrupting hormones to the extent characterized by many. Are we really safe from BPA and hormone disruption?
BPA research is revealing
Endocrine disruption research done using animals with bisphenyl A has prompted many reports warning against consuming foods packaged in BPA-lined containers, including cans. Many types of plastic containers also contain and release BPA. Is the BPA absorbed from these sources as dangerous to our health as the animal studies have indicated?
This question was posed by research presented by Dr. Justin Teeguarden, a toxologist at the U.S. Department of Energy’s Pacific Northwest National Laboratory in Richland, Washington. The research, derived from the analysis of some 280 studies performed on BPA among both animals and humans, indicates that the levels of BPA found in the blood of humans among various studies are quite possibly thousands of times lower than BPA levels found to cause hormone disruption in animal research.
As is the problem with many animal studies, the level of toxicity produced within the body of an animal is often out of proportion with the typical intake of a human. This is not only due to the size of the animal, but the fact that the animal is often faced with other dietary and lifestyle factors that are substantially different than humans.
Dr. Teeguarden commented specifically on this topic. “Looking at all the studies together reveals a remarkably consistent picture of human exposure to BPA with implications for how the risk of human exposure is interpreted.”
The research, funded by the EPA, concluded that the ability of BPA to mimic estrogen in the body requires concentrations far in excess of that found among the human studies to date.
“The term low-dose cannot be understood to mean either relevant to human exposures or in the range of human exposures. However, this is in fact what it has come to mean to the public, as well as many in the media,” said Teeguarden.
Tens of thousands of people tested
In one analysis blood levels of 30,000 human adults, women and babies from 19 countries were compared against levels among 130 animal studies. The toxicity levels produced among the animal studies were up to a thousand times higher than the BPA levels found among the human study group. Even among those animal studies characterized as “low dose,” these levels were 0.8 to 7 percent lower than blood concentrations found among humans.
Another analysis determined that the weakness of BPA’s estrogen reception capability reduces its danger as an hormone disruptor. The research found levels found among humans are many times lower than levels that cause the BPA molecules to attach to estrogen receptors among the cells.
“At these exposure levels, exposure to BPA can’t be compared to giving a baby the massive dose of estrogens found in a birth control pill, a comparison made by others,” explained Dr. Teeguarden.
According to the research, because of BPA’s weak estrogenicity, there is little risk of hormone disruption until BPA levels are substantially greater than evidenced among the human studies to date.
In 2011, Dr. Teeuardan led another study funded by the EPA, which found BPA levels in the blood were “undetectable” after 20 adults consumed foods packaged with BPA. The study concluded:
“During these high dietary exposures, (TOT)BPA concentrations in serum were undetectable in 83% of the 320 samples collected and BPA concentrations were determined to be less than or equal to limit of detection in all samples.”
Does this mean we are good – we do not need to individually reduce our BPA exposure (especially important among mothers)? Does this mean our food manufacturers and their packaging suppliers do not need to find alternative materials to pack our food and beverages in?
Where does BPA come from?
Bisphenol A is a soluble in most organic solvents outside of water. Its phenol groups provide the means for epoxy resins and polycarbonate polymers that can attach to natural molecules. Its use in cans help prevent the degradation of the metals of the cans – most important of which is aluminum. For beverages, the ubiquitous use of plastic has all but decimated the use of glass – a natural biodegradable product made primarily from sand shown to leach little in the way of toxins.
A concern not addressed with this research is the ability of BPA and other estrogenic toxins to bioaccumulate among nature. This means that discarded plastics and their byproducts become accumulated among our sealife, soils and into our food chains. As this bioaccumulation persists, the extent of human exposure becomes greater, along with the risk of massively mutated species of life around us.
The larger concern – not addressed in this focus upon BPA – is the 800 or so chemicals that are either known to or suspected of being hormone disruptors. These range from chemicals in medications to those in pesticides and herbicides that end up in our foods. This astonishing number indicates that we are being bombarded with chemicals that can accumulate in nature and disrupt our hormones.
More research condemns BPA
In 2012, a study and report by the Inter-organization Program for the Sound Management of Chemicals – sponsored by the World Health Organization and others – found that these endocrine-disrupting chemicals were increasingly causing endocrine-related effects around the world.
Among other things, the study found that:
• endocrine disorders are increasing around the world among humans;
• wildlife are increasingly displaying endocrine-related mutations;
• young men are increasingly experiencing poor semen quality;
• genital malformations among children are increasing;
• thyroid disorders are increasing;
• endocrine-related cancers are rising globally;
• early breast development among young women is rising;
• prostate cancers linked to pesticide exposures are prevalent;
This rapid increase in endocrine-related disorders around the world makes this issue larger than our can of tomato sauce. Reducing endocrine-related disorders requires lifestyle changes that include reducing our use of plastic packaging, eating more organic foods, avoiding chemicals around the house and workplace, using a good water filter for drinking water and other prudent practices.
Specific to BPA, steel bottles and cans are typically not lined with BPA, while aluminum cans and bottles typically are. A number of brands are now using BPA-free cans (typically labeled, but sometimes not).
Microwaving polycarbonate plastic containers can also release BPA into food. Washing polycarbonate plastics in the dishwasher may also release BPA.
The growing threat of endocrine-related disorders is also a call to action. Consumers make the ultimate decisions about what we will accept in our foods, packaging and other items. What we buy determines what manufacturers and packaging companies produce. Demand better packaging. Opt for organic. Visit your local farmer’s market.
Teeguarden JG, Calafat AM, Ye X, Doerge DR, Churchwell MI, Gunawan R, Graham MK. Twenty-four hour human urine and serum profiles of bisphenol a during high-dietary exposure. Toxicol Sci. 2011 Sep;123(1):48-57.
Bergman A, Heindel JJ, Jobling S, Kidd KA, Zoeller RT. State of the Science of Endocrine Disrupting Chemicals 2012. WHO Library, 2012.
Adams C. Total Harmonic: The Healing Power of Nature’s Elements. Logical Books, 2012.