by Diana Zuckerman, Ph.D.,
Paul Brown, BS,
France de Bravo, MPH,
Sonia Nagda, MD, MPH
Just like the controversial compound it's designed
to replace, a chemical used in cash register
receipts and other consumer products messes with
hormones, according to research published today.
The study by University of
Texas scientists is the first to link low
concentrations of bisphenol S (BPS) - a bisphenol A
(BPA) alternative - to disruption of estrogen,
spurring concern that it might harm human health.
Researchers exposed rat
cells to levels of BPS that are within the range
people are exposed to.
And, just like BPA, the
compound interfered with how cells respond to
natural estrogen, which is vital for reproduction
and other functions.
“I think we should
all stop and be very cautious about just
accepting this as a substitute for BPA,” said
lead author and biochemist Cheryl Watson.
“And not just BPS.
We should question the whole process about how
we introduce chemicals into the marketplace
without properly testing them first.”
is a chemical used to make plastics.
It is frequently used in sports
equipment, water bottles, medical devices, as a coating or lining in
food and beverage cans, and in credit card receipts. It leaches out
of plastic into liquids and foods, and the Centers for Disease
Control and Prevention found measurable amounts of BPA in the
bodies of 93% of the U.S. population studied.
Infants and children are estimated to have the highest daily intake
of BPA because,
“they eat, drink, and breathe more
than adults on a pound for pound basis,” according to the U.S.
National Toxicology Program.
Until recently, most plastic baby
bottles contained BPA.
The chemical is especially likely to
leach out of plastic when it is heated, such as when a baby bottle
is warmed in the microwave, thereby allowing the BPA to be ingested
and enter the bloodstream.
On any given day, several times a day, a
baby might drink liquid formula that was sold in a can lined with
BPA and then warmed in a plastic baby bottle containing BPA.
If BPA is in so many different items that we use every day, it must
have been proven safe, right? Unfortunately not. BPA was developed
as a synthetic estrogen, and it mimics and interferes with the
action of that hormone, which helps regulate development and
It is called an “endocrine disruptor”
because it affects the body’s own hormones (its endocrine system) in
ways that could be potentially harmful. It is difficult to determine
just how much BPA, or how much of any hormone-disrupting chemical,
Toxicologists test chemicals at very
high doses in animals to see if they die or if their health is
After establishing the dangerous dose,
much lower doses are then allowed in products used or consumed by
humans. These products are labeled safe, despite the fact that the
chemicals in them have rarely been tested at low doses in animals,
and were never tested in humans at all.
Furthermore, recent research shows a
paradoxical phenomenon with BPA and other chemicals that affect the
endocrine system: their impact on health is sometimes greater at low
doses than at high doses.
While early concerns about BPA’s health effects were based primarily
on animal studies and research on cells, there is increasing
evidence from studies in humans that BPA can cause serious harm,
such as increased risk of heart disease, diabetes, obesity, and
Effects of BPA in Animals
Before studies were conducted on humans, dozens of studies were
conducted and are still being conducted in the lab.
The American Chemical Society,
the national professional association for chemists, reported that
153 government-funded BPA experiments on lab animals and tissues
found harmful effects while only 14 did not.
BPA experiments on rats linked the chemical to precancerous lesions
in the prostate and mammary glands, and to early puberty in females
at BPA dosages similar to human exposures, according to a 2008
report on BPA by the National Institutes of Health’s National
Another study on rats showed that
exposure to BPA, as well as exposure to fungicides and pesticides,
appears to cause ovarian cysts and fewer eggs in offspring - as many
as three generations down the line (a rat’s great “grandchildren”).
Studies of mice exposed to BPA in the womb found that these mice
tended to put on more body fat after birth. 
However, as adults the BPA-exposed mice were the same size and
weight as mice that were not exposed to BPA in the womb.
A more recent study, published in 2012,
found that adult mice given low doses of BPA twice a day for eight
days did not gain weight, but they did develop problems with their
metabolism that would lead to type 2 diabetes. 
Studies have linked the hormonal effects of BPA from canned cat food
to the epidemic of hyperthyroidism in cats, especially females.
Studies of rats and mice have linked BPA to hyperactivity and
various brain and behavioral changes, including increased anxiety
and impaired cognition.   
In 2008, the first study of nonhuman
primates found that BPA levels were associated with cognitive
problems that could affect learning and memory.
The National Toxicology Program’s 2008 report recommended that more
studies be conducted on BPA’s health effects on humans, and the
“The possibility that bisphenol A
may alter human development cannot be dismissed.” 
BPA Affects Humans
Since 2008, studies of humans have added greatly to concerns about
the health risks of BPA.
A major study published in January 2010,
based on a major government data set (the
NHANES), found that adults with higher levels of BPA in
their urine were more likely to have heart disease, even when other
variables were statistically controlled.
The NHANES data also showed a separate
link between levels of BPA in urine and high blood pressure, a major
contributor to heart disease.
These findings were similar to a study
published in the Journal of the American Medical Association in
2008, which found a link between BPA levels and diabetes and heart
disease, even when obesity was statistically controlled. 
Studies show cashiers
have elevated levels
A study published in Circulation in 2012
based on research in the UK supported these findings.
At least two other articles published in 2012 conclude that BPA
exposure puts humans at risk for metabolic disorders and obesity.
One of the articles (a review) focused
on in utero exposure to BPA, which Dr. Frederick vom Saal and
his co-authors say appears to program the fetus to develop into an
As a weak estrogen, BPA has been shown to cause pre-cancerous
growths in the mammary glands of rodents, so an important question
is whether it could increase a woman’s chances of developing breast
cancer, since breast cancer can feed on estrogen. Laboratory studies
where scientists look at cells taken from the body suggest that BPA
may cause breast cells to change and become cancerous. 
Not only does regular BPA exposure
potentially increase a woman’s chances of developing breast cancer,
but it appears to also interfere with chemotherapy for breast cancer
patients, possibly reducing its efficacy.
There is also evidence of harm to fertility and sexual activity. A
2009 research article reported that men who were exposed to very
high levels of BPA at work were four times as likely to experience
erectile dysfunction and reduced sexual desire compared to men who
did not work with BPA.
BPA-exposed workers were also seven
times as likely to have problems with ejaculation.
Although the men in that study had much
higher levels of BPA exposure than the average man, this study
demonstrates BPA’s potential to harm men’s sexual and reproductive
health at high levels and it raises questions about lower levels of
exposure. Research is needed to study the effects of more typical
BPA exposures (non-occupational exposures) on men’s sexual health.
BPA can also affect a woman’s fertility and has been linked to
Studies have shown that women undergoing
in vitro fertilization (IVF) who have higher levels of BPA
have more difficulty becoming pregnant due to the lower quality of
their eggs, fewer fertilized eggs, and reduced levels of estrogen.
images are printed
on thermal paper
that contains BPS.
The FDA Drags
Its Feet As Other Countries Take Action
After a Food and Drug Administration (the
FDA) analysis concluded that BPA was safe in 2008,
the FDA Science Board, which consists of independent scientists who
do not work for the FDA, recommended in October 2008 that the FDA
analyze the research literature again, relying less on two
industry-funded studies of rats and taking into account the best
It also recommended that new research be
conducted to examine BPA safety concerns.
Meanwhile, Canada announced in 2008 that it intended to reduce
infant and newborn exposure to BPA by banning its use in baby
bottles, setting stringent standards for the amount of BPA allowed
to migrate from the can into infant formula, and working with
industry to develop alternative food packaging.
In October 2010, Canada became the first
government in the world to add BPA to its list of toxic substances,
in preparation for regulating its use. 
France and Denmark joined Canada in
banning BPA from baby bottles in 2010, and the European Commission
voted that same year to ban European Union countries from making and
selling baby bottles with BPA, beginning in 2011.  In
December 2012, the French parliament voted to ban BPA from all baby
food packaging in 2013 and from all food containers in 2015.
In January 2010, the FDA announced that its National Center for
Toxicological Research in cooperation with the National Toxicology
“carrying out in-depth studies to
answer key questions and clarify uncertainties about the risks
The FDA said that it,
“shares the perspective of the
National Toxicology Program that recent studies provide reason
for some concern about the potential effects of BPA on the
brain, behavior, and prostate gland of fetuses, infants and
The FDA also recognized “substantial
uncertainties” with the interpretation of BPA studies and how BPA
may affect human health.
Despite those uncertainties, the FDA
said it supported,
“a more robust regulatory framework
for oversight of BPA to be able to respond quickly, if
necessary, to protect the public.”
However, the agency said at that time
that it was,
“not recommending that families
change the use of infant formula for foods, as the benefit of a
stable source of good nutrition outweighs the potential risk of
BPA exposure.” 
In March 2012, the FDA finally responded
to a 2008 petition from the Natural Resources Defense Council (NRDC).
The petition had asked the FDA to ban
BPA’s use in food and beverage packaging, based on the studies at
the time. After ignoring NRDC’s petition for years, the FDA - under
pressure of a law suit - responded that there was insufficient
evidence to remove the chemical from the products in which it is
currently being used, and that the Agency would continue to review
studies of BPA. 
It is important to note that the FDA’s
rejection of the petition was based on the studies that the NRDC had
submitted with the petition in 2008, not on the more recent studies.
Ban BPA in the U.S.
In March 2009, Suffolk County in New York became the first county in
the U.S. to ban BPA in baby bottles and “sippy” cups, and in May of
2009, Chicago and Minnesota followed.  
Also in 2009, Connecticut passed a law
banning BPA in children’s reusable bottles and cups as well as
infant formula and baby food containers, which went into effect in
Members of the U.S. Congress have introduced BPA-related legislation
since 2009 without success.
As of spring 2012, there was a bill in
the Senate (S. 136) introduced by Senator Dianne Feinstein
(D-CA) that would ban BPA in children’s products, and a bill in the
House (H.R. 432), sponsored by Representative Edward Markey
(D-MA), that bans BPA in food containers.
BPA is found in polycarbonate (PC) plastics, which are typically
clear and hard, marked with the recycle symbol “7″ or may contain
the letters “PC” near the recycle symbol.
To avoid the risks of baby bottles with
BPA or other questionable chemicals, look for packages that say
“BPA-free” and also consider alternatives such as glass bottles. And
to avoid warming up food in plastic containers with these chemicals,
use only stoneware, china, or glass dishes and containers in your
In 2008, manufacturers such as Playtex and Nalgene and retailers
such as Wal-Mart pledged to remove BPA from their products and
stores by the end of the year.
In March 2009, the six major
manufacturers of baby bottles in the United States announced that
they would no longer sell baby bottles made with BPA in the U.S.
A few days later, SUNOCO, a BPA
manufacturer, announced that it would require companies using BPA in
their products to confirm that none of those products would be used
to hold food or water for children under 3 years of age.
These voluntary efforts were a result of
negative publicity and consumer concerns about BPA.
BPA in Cans
BPA is still in most canned food and beverages sold to people and
pets in the U.S. and other countries.
Some companies are not waiting for a ban
and are voluntarily removing BPA from their food packaging. Eden
Foods began using BPA-free cans in 1999 and now uses BPA-free cans
for everything except highly acidic tomato products. 
According to Eden, it costs the company
$300,000 more a year to produce BPA-free cans, which are 14% more
expensive than industry standard cans; this translates into about 2
cents more per can. 
Vital Choice introduced new cans and
pouches for its fish products at the end of 2008. It
was not until 2012 that a major manufacturer, Campbell’s, announced
that it would seek to phase out the use of BPA in its canned foods.
The announcement was made after the
Breast Cancer Fund publicized the results of its tests on canned
foods marketed to kids: the tests found that Campbell’s soups and
other popular products had some of the highest levels.
Are BPA Any
'Substitutes' Safer Than BPA?
In response to new laws, regulations, and consumer concerns about
BPA, many products are being made with a new chemical, bisphenol S
(BPS). As a new compound, little is known about its safety, but a
new study indicates it is likely to cause problems similar to BPA by
This new research suggests that
substituting BPA with new compounds that have not been adequately
tested for safety will not necessarily provide any health benefits.
What is needed is to test the safety of
potential BPA substitutes before they can be sold.
Individual Efforts to
Reduce Exposure to BPA
While we wait for more research to be conducted, is it possible to
avoid BPA and substitutes that may be just as worrisome?
A recent study suggests that we can
significantly lower our levels of BPA by strictly avoiding many
packaged foods and beverages and also changing how we prepare and
In 2012, Ruthann Rudel from the Silent Spring Institute and
her co-authors published a study showing how BPA levels in the body
are affected by consuming foods and beverages that have come into
contact with BPA.
Twenty participants in 5 families
switched from their normal diet, including canned and packaged
items, to a diet consisting of only fresh, unprocessed foods for 3
days. Their BPA levels were tested before the switch, during the 3
days of BPA-free eating and drinking, and again after they had
returned to their normal diet.
The researchers found that BPA levels
went down significantly when people ate foods and drank beverages
that had never spent time in cans, plastic bottles, or plastic food
storage containers made with BPA and had never come into contact
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