By Dr. Mercola
Have you stopped carrying plastic water bottles and using plastic utensils and food containers in order to avoid the toxic chemical bisphenol-A (BPA)?
This is a wise decision, but it may not be enough to protect you from this toxin's ill effects.
This is because BPA is not only found in plastics; it's also found in the lining of nearly all canned foods and beverages, and it turns out this source of exposure could be increasing your BPA levels by 1,000 percent!
Eating Food from Canned Products Increases BPA Exposure by 1,000 Percent
It's been more than two years since a series of tests by Consumer Reports revealed that many leading brands of canned foods -- from soup and tuna to juice and green beans -- contain BPA.
Now new research from the Harvard School of Public Health revealed what impact eating canned goods has on your body's BPA level.
The study was very straightforward, with one group of participants eating canned soup for five days, and another group eating freshly made soup.
The groups then took a two-day break from canned soup and switched (so each group had a period of eating canned versus fresh soup).
The researchers collected urine samples to determine urinary concentrations of BPA and found that eating canned soup had a significant impact.
Specifically, those eating fresh soup had BPA levels that averaged 1.1 micrograms per liter. The canned soup group, however, had levels of 20.8 mcg per liter, which is an increase of more than 1,000%!
Doctoral student Jenny Carwile, who led the study, noted that given this new finding, canned goods may be an even greater contribution to your BPA levels than plastics.
"We've known for a while that drinking beverages that have been stored in certain hard plastics can increase the amount of BPA in your body. This study suggests that canned foods may be an even greater concern, especially given their wide use," she said.
While the study only included canned soup, it's likely that other canned goods, including soda, may result in similar exposures.
According to Consumer Reports' 2009 testing, the levels of BPA can vary greatly from one can to another, but their estimates revealed just a couple of servings of canned food can exceed the safety limits for daily BPA exposure for children. And whether or not a canned good is organic makes no difference (although some manufacturers have begun to come out with BPA-free canned goods).
Cash Register Receipts and Money Also Contain BPA
It's becoming evident that simply avoiding plastics is not nearly enough to avoid BPA, as this toxic chemical is present in places you would least expect.
For instance, in a study published in Environmental Science and Technology, researchers analyzed paper currencies from 21 countries for the presence of BPA, and the chemical was detected in every sample. They also measured the transfer of BPA from thermal receipt paper to currency by placing the two together in a wallet for 24 hours. This dramatically increased the concentrations of BPA on the money, which suggests that receipts are highly contaminated.
The researchers estimated that you could be absorbing a few nanograms of BPA every day just from handling paper currency! This builds on prior research that also revealed thermal printer paper could be a dangerous source of BPA:
- A study in Analytical and Bioanalytical Chemistry found that of 13 thermal printing papers (the type often used for receipts) analyzed, 11 contained BPA. Holding the paper for just 5 seconds was enough to transfer BPA onto a person's skin, and the amount of BPA transferred increased by about 10 times if the fingers were wet or greasy.
- A study commissioned by Environmental Working Group (EWG) detected BPA on 40 percent of receipts they tested from gas stations, supermarkets and other common retail outlets. According to EWG, "the total mass of BPA on a receipt is 250 to 1,000 times greater than the amount of BPA typically found in a can of food or a can of baby formula."
At this time it's unclear how much of your body burden of BPA is coming from these paper sources, but it would be wise to seek to limit or avoid carrying receipts in your wallet or purse, as it appears the chemical is transferring onto other surfaces it touches. It would also be wise to wash your hands after handling receipts and currency, and avoid handling them particularly if you've just put lotion or have any other greasy substance on your hands, as this may increase your exposure.
BPA-Free Plastic is Not a Guarantee of Safety
Given the concerning health risks associated with BPA, the chemical has been banned from use in baby bottles in Canada and Europe, and many other companies have voluntarily removed it from their plastic products.
The result has been an outpouring of BPA-free plastics, everything from food containers and water bottles to pacifiers and baby toys can now be found in a BPA-free version.
This, however, does not mean you're protected from BPA!
A study released in 2011 showed that tests on plastics using the BPA-free label have not been conducted under real-world conditions like running the plastics through a dishwasher or heating them in a microwave.
In the "real-world," 95 percent of all plastic products in the study tested positive for estrogenic activity, meaning they can still disrupt your hormones even if they carry a BPA-free label. Even more disconcerting is the finding that BPA-free plastics in some cases leached more BPA than the non-BPA free plastics.
Does this mean there is no safe plastic when it comes to storing or serving your food or drinks? It appears so. You even should be careful about switching to metal water bottles in lieu of plastic ones, as some may contain epoxy liners that contain BPA.
BPA Health Risks are Well-Established
BPA is an endocrine disrupter, which means it mimics or interferes with your body's hormones and "disrupts" your endocrine system. The glands of your endocrine system and the hormones they release are instrumental in regulating mood, growth and development, tissue function, metabolism, as well as sexual function and reproductive processes.
Chemicals like BPA can exert their effects by:
- Mimicking the biological activity of your hormones by binding to a cellular receptor. This can initiate your cell's normal response to the naturally occurring hormone at the wrong time or to an excessive extent (agonistic effect).
- Binding to transport proteins in your blood, thus altering the amounts of natural hormones that are present in your blood circulation.
- Interfering with the metabolic processes in your body, affecting the synthesis or breakdown rates of your natural hormones.
Some of the greatest concern surrounds early-life, in utero exposure to BPA, which can lead to chromosomal errors in your developing fetus, causing spontaneous miscarriages and genetic damage. But evidence is also very strong showing these chemicals are influencing adults and children, too, and leading to decreased sperm quality, early puberty, stimulation of mammary gland development, disrupted reproductive cycles and ovarian dysfunction, cancer and heart disease, among numerous other health problems.
BPA Linked to Obesity and Insulin Resistance
Two studies from 2011 added yet another concerning health impact of BPA exposure: obesity. The first, published in Environmental Research, found that "higher BPA exposure is associated with general and central obesity in the general adult population of the United States."
The other, published in the Clinical Journal of Endocrinology and Metabolism, found that BPA is associated not only with generalized and abdominal obesity, but also with insulin resistance, which is an underlying factor in many chronic diseases.
Unfortunately, as one of the world's highest production-volume chemicals, BPA has been found in 90 percent of all people tested in the United States and is commonly found in the umbilical cords of babies in utero, which means entire populations -- and generations -- may be suffering from this widespread toxic exposure.
You Can Choose to Avoid BPA
It's important to realize that you have a choice in which foods and consumer products you buy, and by exercising this choice responsibly you can help influence industry to get BPA out of their products for good, while at the same time helping reduce your, and your family's, exposure to this dangerous chemical.
At the top of the list of products to boycott would be canned foods and soda cans, along with all BPA-containing plastics.
Other sources of BPA to be aware of include:
- Certain tooth sealants
- Certain BPA-free plastics (which can contain similar endocrine-disrupting chemicals)
Make an effort to support the companies that have already removed BPA from their products, or those that offer products that never contained it (such as baby toys made from natural fabrics instead of plastic). If enough people refuse to buy BPA-containing goods, companies will have no choice but to follow suit and get this toxin out of their products.
For information on companies that are making efforts to explore BPA-free packaging or have already begun phasing BPA out of their products altogether, see the report Seeking Safer Packaging: Ranking Packaged Food Companies on BPA by the environmentally oriented investment firm Green Century and As You Sow, a non-profit working toward increasing corporate social responsibility.
How You Can Easily Reduce the Damage of BPA Exposure
It is a fascinating fact that we humans have an exceptionally difficult time breaking down BPA, but certain "friendly bacteria" in our gut have evolved the ability to degrade it, as well as reduce the intestinal absorption of it. This is why taking a quality probiotic formula and/or consuming fermented foods like homemade fermented vegetables, raw grass-fed organic kefir, or Kimchi, may make all the difference in protecting you from the adverse effects of unavoidable BPA exposures.
If you have not yet made the transition to fermented foods then you can consume a high-quality probiotic. Also, the website GreenMedInfo.com contains a list of a dozen natural substances, including black tea, royal jelly and the flavonoid quercetin, that may be of value in protecting you against the damaging effects of BPA exposure.