This is major although it is actually downplayed here. It pretty
well informs us that the earlier conclusions were biased by an agency
other than that tested for and as a result BPA is fully absolved.
The anti BPA campaign has been going strong for two decades now and
stopping it cold is good news. I personally was never convinced
simply because the tale was just too convenient to tin can makers
who had to upgrade.
Can liners have given us a far higher quality of canned food as a
matter of course. Thus allaying trumped up fears over the necessary
liner is good.
It also shows just how easy it is to slant the science on an
inconvenient commercial threat. Once wrong work is published in an
obscure study it is often accepted just because it has not been
seriously questioned. This makes the pay off for fraudulent work
very safe.
It also a sharp reminder that much accepted science is actually
untested science simply because it had not been practical or
worthwhile at the time.
We do not know what generated the original results, but that two
different substances were tested to effect at the time should have
made the work suspect. What else was tossed into the feed?
Previous Studies on
Toxic Effects of BPA Couldn't be Reproduced
by Timothy Wall for UM News
Columbia MO (SPX) Jan 04, 2013
Following a three-year
study using more than 2,800 mice, a University of Missouri researcher
was not able to replicate a series of previous studies by another
research group investigating the controversial chemical BPA. The MU
study is not claiming that BPA is safe, but that the previous series
of studies are not reproducible.
The MU study,
published in the Proceedings of the National Academy of Sciences,
also investigated an estrogenic compound found in plants, genistein,
in the same three-year study.
"Our findings
don't say anything about the positive or negative effects of BPA or
genistein," said Cheryl Rosenfeld, associate professor of
biomedical sciences in MU's Bond Life Science Center.
"Rather, our
series of experiments did not detect the same findings as reported by
another group on the potential developmental effects of BPA and
genistein when exposure of young occurs in the womb."
Creating reliable data
on the effects of the chemicals on mice is important to human health
since people are frequently exposed to BPA and genistein and humans
share similar biological functions with mice. BPA is a chemical used
in certain plastic bottles and may be found in the lining of some
canned goods and receipt paper. Genistein occurs naturally in soy
beans and is sold as a dietary supplement.
Research by Fredrick
VomSaal, professor of biological science at MU, and others suggests
the chemicals may have other adverse effects on many animals,
including humans.
Researcher who
conducted the original series of experiments claimed that exposure to
BPA and genestein resulted in yellow coat color, or agouti, offspring
that were more susceptible to obesity and type 2 diabetes compared to
their brown coat color, healthy siblings.
However, Rosenfeld and
her team did not obtain the same results when repeating the study
over a three-year period.
After failing to
repeat the original experiments findings with similar numbers of
animals, Rosenfeld's group extended the studies to include animal
numbers that surpassed the prior studies to verify that their
findings were not a fluke and to provide sufficient number of animals
to ensure that significant differences would be detected if they
existed.
However, even these
additional numbers of animals and extended experiments failed to
reproduce the earlier findings. However, the current studies
demonstrate that a maternal diet enriched in estrogenic compounds
leads to a greater number of offspring that express an agouti gene
compared to those that do not, even though equal ratios should have
been born.[ that actually could
be a fluke - arclein]
"This finding
suggests that certain uterine environments may favor animals with a
'thrifty genotype' meaning that the agouti gene of mice may help them
survive in unfavorable uterine environments over those mice devoid of
this gene, Yet, the downside of this expression of the agouti during
early development is that the animals may be at risk for later
metabolic disorders, such as obesity and diabetes" Rosenfeld
said.
"In this aspect,
humans also have an agouti gene that encodes for the agouti signaling
protein (ASIP) that is expressed in fat tissue and pancreas, and
there is some correlation that obese individuals exhibit greater
expression of this gene compared to leaner individuals.
Therefore, the agouti
gene may have evolved to permit humans the ability to survive famine,
but its enhanced expression may also potentiate metabolic diseases
under bountiful food conditions."
While the research
casts doubt on the previous study, Rosenfeld said that by
understanding the genetic profile of the mice in the first series of
studies, scientists could learn more about the correlation between
certain genes and obesity. This could eventually influence prevention
and treatment programs for patients with diabetes and other
obesity-related diseases in humans.
For more details on
the discovery, click here.
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