Nature要为孟山都背书啊？
孟家的实验只作了三个月， 而肿瘤是在四个月后才出现。。。
New research out of France has linked both an herbicide and a genetically
modified corn to organ damage, tumors and early death among rats, prompting
a call for greater regulation of GM foods among sustainable agriculture
advocates.
The study – published Wednesday in Food and Chemical Toxicology – found
that rats who were exposed to Roundup, a weed killing herbicide, and rats
who were fed Roundup-resistant corn developed mammary tumors, kidney and
liver damage and died earlier than those in the control group.
According to the authors, this is the first study to examine the long-term
effects of genetically modified Roundup Ready corn, or NK603, which is
produced by biotech corporation Monsanto and has been approved for use in
both the European Union and the United States.
Previous studies have examined the effects of NK603 on animals over the
course of 90 days, while this study looked at a two-year period.
“There were no adverse effects in a 90-day feeding study on rats with NK603
maize grain…” says the EFSA GMO Panel in its scientific opinion on the
corn. “The EFSA GMO Panel is of the opinion that maize NK603 is as safe as
conventional maize. Maize NK603 and derived products are unlikely to have
any adverse effect on human and animal health in the context of the intended
uses.”
The French study, however, found a series of adverse health effects in rats
fed with the corn.
In this study, conducted on 100 female and 100 male rats, the animals were
given either Roundup-resistant corn, the Roundup herbicide or both. Animals
in all three of these test groups experienced adverse health effects and
died earlier than rats in the control group, who were given regular corn and
plain water.
“The results were really alarming,” said Professor Gilles-Eric Seralini,
co-director of the Risk Quality and Sustainable Environment Unit at the
University of Caen, France and the study’s lead researcher. Mammary tumors
began to appear in females after 4 months, he said, and “after one year
there was a high increase of a number of (kinds of) tumors. Almost every
female rat had two or three tumors,” said Seralini in a Wednesday press
conference.
Up to 50 percent of males and 70 percent of females fed with GM corn died
before their deaths could be attributed to normal aging, compared with 30
percent of males and 20 of females in the control group who died prematurely.
Tumors grew more frequently and rapidly among most test groups than among
the control group. After 23 months, 50 to 80 percent of the treated female
rats (percent depending on group) had developed tumors, while 30 percent of
female control rats had tumors. The group treated with Roundup showed the
greatest incidence of tumors. Of the females in this group, 80 percent
developed at least one and up to three tumors.
Treated males developed tumors largely in their kidneys and skin, and were
two times more likely to have a tumor during the 23rd month than control
males. Treated males also suffered liver damage at greater rates.
“The results of the study presented here clearly demonstrate that lower
levels of complete agricultural glyphosate herbicide formulations (such as
Roundup), at concentrations well below officially set safety limits, induce
severe hormone-dependent mammary, hepatic (liver) and kidney disturbances,”
write the authors.
Test rats were given varying doses of Roundup in their water and NK603 corn
in their feed. The lowest doses administered in the study were lower than
levels allowed in both the EU and U.S., according to the study.
The lowest treatment level of Roundup alone was at the “usual contaminating
level of tap water,” explained Seralini.
Test animals experienced severe adverse health effects even at these lowest
levels. The authors say this result suggests that both products cause a
hormonal imbalance.
“Our data show that, as is often the case for hormonal diseases, most
observed effects in this study were not proportional to the dose of the
treatment.”
“This implies that both the NK603 maize and R(oundup) may cause hormonal
disturbances in the same biochemical and physiological pathway,” concludes
the study.
The fact that groups treated with GM corn alone reacted similarly to those
treated with the only the herbicide was surprising, says Seralini.
“We were really interested by the results of the GMO alone that was not
treated with Roundup,” said Seralini. “The groups with the GMO
surprisingly also had hormonal disruptions and there were also mammary
tumors.”
After a detailed analysis of the chemical composition of the animals’ diets
, researchers found that two compounds in plants that protect animals
against mammary tumors and toxicity of the kidney and liver were reduced to
51 percent with the consumption of the GM corn. They concluded that an
enzyme that is over-expressed in 80 percent of GMOs was causing this effect,
explains Seralini.
An estimated 70 percent of corn grown in the U.S. is Roundup Ready.
According to Monsanto’s safety assessment, NK603 is corn into which DNA is
inserted to make the plant resistant to the harmful effects of Roundup.
Prior studies have shown that the CP4 EPSPS proteins expressed in Roundup
Ready corn do not produce toxicity in mice, nor are they similar to known
allergens or toxins, and they are rapidly digested in vitro.
Tom Sanders, head of the nutritional sciences research division at King’s
College London, expressed concern over the methods used in the French study.
“This strain of rat is very prone to mammary tumors particularly when food
intake is not restricted,” said Tom Sanders, head of the nutritional
sciences research division at King’s College London according to Reuters
wire service. “The statistical methods are unconventional … and it would
appear the authors have gone on a statistical fishing trip.”
Call to Action
The authors of the study, along with the Sustainable Food Trust – a
nonprofit global group that promotes sustainable agriculture – say these
results highlight a need to further supervise the approval and sale of
genetically modified foods worldwide. The NGO stated the following in a
press release Wednesday:
In light of these findings the Sustainable Food Trust sees the call to
action as:
- A pre-cautionary review of the regulatory framework for testing Pesticides
and GM foods
- The requirement for foods containing GM ingredients or their derivatives,
or from animals fed on a GM diet, to be clearly labeled
- Further independent research exploring the potential human health effects
of consuming these products.
The fact that GMO foods are not labeled in the U.S. is “in my opinion a
very severe problem,” said Seralini during the Wednesday press conference.
Consumers should have the freedom to know what is in their foods, he says.
“In Europe we have this labeling and it enables us to avoid these compounds
if necessary,” he said.
This study comes just before California is set to vote on whether or not to
mandate labels for GMOs, which will be on the ballot as Proposition 37 this
fall.
“The results of this study are worrying,” said Proposition 37 California
Right to Know Campaign Manager Gary Ruskin in a statement Wednesday. “They
underscore the importance of giving California families the right to know
whether our food is genetically engineered, and to decide for ourselves
whether we want to gamble with our health by eating GMO foods that have not
been adequately studied and have not been proven safe.”
Seralini says the results of his research also point to the need to test the
effects of GMOs for two years – the average lifespan of a rat – rather
than for 90 days, since the tumors found in this study appeared after four
months had passed.
He also recommends that the U.S. government rely less on company tests when
making regulatory decisions about the company’s products.
The study was supported by the independent research organization, CRIIGEN
and was published in the Food and Chemical Toxicology. It is available on
the Sustainable Food Trust’s website.
