Sự Thật về thuốc Siêu Nạc (Clenbuterol)

[VinhL]

Trích:
http://serendip.brynmawr.edu/biology...1/paluska.html

TAINTED MEAT: CLENBUTEROL USE IN THE MEAT INDUSTRY
Elizabeth Paluska

Humans are currently giving livestock hormones, steroids and antibiotics to increase the animals' value in the meat industry where size matters. The meat from these animals eventually finds it way to your plate. These animals that we are consuming are being "pushed" by an outside force, but how well do they "bounce back" and what are the consequences in consideration of the food chain? Perhaps not only are we disrupting the biological system of livestock, but ourselves as well.

This issue is currently being explored in the livestock and meat industry due to the increase of a drug called clenbuterol HCl. This drug has become popular due to its desirable effects in livestock and their market value. However, this is not merely a social issue. Biology is inevitably a multidisciplinary and multifaceted field. In examining the sociological and economic factors of this phenomenon, one must also consider the biological consequences and vice versa. We must investigate to see if clenbuterol administration to livestock has consequences that disrupt biological systems, despite the economic and social factors.

Clenbuterol HCl is a beta-adrenergic agonist that is used illegally in the United States and Europe to increase the leanness and protein content of cattle, swine and horses. According to studies done by the Agricultural Research Service, consumption of meat from veal calves exposed to clenbuterol can poison humans. Also recent studies by the ARS suggest that residues in edible tissues in swine exposed to clenbuterol remain high after slaughter, despite a withdrawal period from the drug. Their research has shown that even after a seven-day withdrawal period, the residues of the drug still exceeded European maximum residue levels. In conclusion, clenbuterol use in swine and other livestock was determined to be inconsistent with human consumption standards. Often the drug is used in competitions at livestock shows, but research by the Food Safety and Inspection service has found many incidences of clenbuterol use in feedlots. This phenomenon is not one of the past despite research dating back to the early nineties that resulted in the restriction of distribution and use of the drug in livestock.

Often when ingested, animals will break the clenbuterol and other similar chemical compounds into non-toxic products. However, sometimes the chemical is broken down into a toxic product that is as toxic or even more toxic than the originally ingested clenbuterol (ARS). Most of the studies of the effects of clenbuterol are done on cattle due to the considerable usage of this chemical in the livestock industry. Also, young calves are given this drug to increase leanness and protein content as they are confined and prepared for the production of veal. According to the Agricultural Research Service, after calves are exposed to clenbuterol, the chemical is distributed throughout the body in numerous organs. Many of these organs, including the liver, kidney, muscle, and fat are edible organs that will eventually end up in the meat industry. They also stated that in tissues such as muscle and kidney, the parent clenbuterol represented 40-60% of the total residue. Their research also shows that the elimination of clenbuterol in cattle is significantly slower than in other species.

How does this effect us? Recorded incidents of health problems associated with the consumption of meat with traces of clenbuterol include increased heart rate, muscular tremors, headache, nausea, fever and chills. According the Food Safety and Inspection Service, in 1990, there were 135 persons in Spain that reported illness after consuming meat that was later found to have traces of clenbuterol. Another incident involving 140 people was reported in 1994. Other outbreaks have been reported in France and Ireland. Several such outbreaks have been reported in the United States. Currently there are no available public studies on the long-term effects of exposure to clenbuterol in humans. Although most of these immediate symptoms are non-fatal, there is always the possibility that the effects overtime could be more serious. The majority of the research studies I found were about clenbuterol levels in animals - most often is major organs such as the liver. There are no analyses of human tissue. Since the drug is not fatal, perhaps the government believes there is no need to look for it. But are we missing something? Or perhaps there is something we are not being told. Currently, clenbuterol is illegal for edible animals. Ideally, the government can assume that the drug poses no threat to the American consumer. However, clenbuterol slips through the loopholes of the meat industry and onto our plate.

Clenbuterol has recently been brought to the public's attention due to its common usage in livestock fairs and competitions (6). I interviewed a farming family from my home state that had quit showing livestock at the county and state level due to the use of growth steroids, including clenbuterol. "It's a well known fact that a lot of the competition at county and state fairs use clenbuterol to enhance the appearance of their cattle. It helps give the steer a muscular physique. We used to show our livestock, but keeping up with the competition means using growth steroid. Those cattle end up on your plate. We don't believe in that," states Emily Kinsinger of Ottumwa, Iowa. The use of clenbuterol and other growth steroids have been reported in many states where livestock are shown for competition. An interesting aspect to this phenomenon is that the majority of livestock at fairs are shown by children and young adults. Kinsinger explains, "Everyone knows that it is not allowed in competition and that it's illegal. But there is money involved, so people ignore the rules. Especially since it's not that hard to get." The FDA is currently investigating traces of clenbuterol found in steer, sheep and swine in livestock competition. According to the Food Safety and Inspection Service, most of the clenbuterol comes illegally from veterinarians who have approved use of clenbuterol for horses and other countries where the drug is approved for animals not used for food. There are no studies about the long-term exposure to clenbuterol in humans. Kinsinger comments, "We can't really know the long-term effects on cattle headed to the meat industry because of their inevitably short life span."

According to Campbell, organisms are open systems that interact continuously with their environment. Life involves a constant exchange of materials and energy between the system and the surroundings. Organisms' homeostatic feature can be held accountable for "bouncing back" from a change in the environment. But what happens when the energy in a certain system changes and the effects are not caused by a force of nature, but by the force of another organism - a chemical change in the environment. Ultimately, this "push" on the homeostatic nature of livestock ends up "pushing" humans as well. Clenbuterol ends up not only in cattle, swine and sheep, but on our plate and finally in our system. This is why we must consider the consequences long and short term of this drug and its result in the food chain.
WWW Sources
1)Agricultural Research Service, ARS homepage
2)Agricultural Research Service, Clenbuterol HCL in Hostein Calves
3)Agricultural Research Service, Clenbuterol Residues in Swine
4)Food Safety and Inspection Service, Clenbuterol-backgrounders
5)Sperling Bovine Biomedical Foundation
6)Ohio Department of Agriculture,Livestock Tampering News Release
Other Interesting Web Sites about Clenbuterol and the Meat Industry
Cornell University Animal Science Web Server
National Drug Strategy Network
Food and Nutrition Digest
The Synthesis, Pharmacology and Immunology of Some Clenbuterol Analogues
State Institute for Quality Control of Agricultural Products-Netherlands

[VinhL]

Trích:
FS3_-_Clenbuterol.pdf
www.moniqa.org/webfm_send/568

MoniQA Fact Sheet No 3 on:
Clenbuterol (March 2009)
Network of Excellence supported by the European Commission under FP6
Coordinator: Roland Poms (ICC) www.moniqa.org
Globalized trade in food means more choice for
consumers. However, globalization can also threaten
human health. Funded by the European Union, MoniQA
(Monitoring and Quality Assurance in the Food Supply
Chain) brings together 33 organisations from around the
world that are working together to help food
manufacturers, retail outlets and regulatory bodies to cope
with the challenges posed by a globalised food economy.
This factsheets provides an overview of clenbuterol and its
detection in Chinese pork.
The Clenbuterol Molecule
What is Clenbuterol?
Clenbuterol is a bronchodilator used in
asthma medicine worldwide for the
treatment of allergic respiratory disease in
horses. A common trade name is
Ventipulmin, and it can be used both orally
and intravenously. Clenbuterol is also a
non-steroidal anabolic and metabolism
accelerator, through a mechanism not well
understood, which is why it is used illegally
by athletes to build muscle. Its ability,
however, to induce weight gain and ensure
a greater proportion of muscle makes its
illegal use in livestock popular.
Clenbuterol accumulates in the human body
through ingestion. It is heat stable only
decomposing at temperatures over 172
degrees Celsius. Thus, cooking cannot easily
eliminate toxicity. Long-term consumption
can lead to malignant tumours but it also
poses dangers to patients who have high
blood pressure or diabetes.
Patients and those with excess intake often
share similar symptoms including
palpitations, nausea, vomiting, dizziness,
chest tightness, anxiety, shaking, weakness,
and instability.
Clenbuterol in Pork
Clenbuterol accelerates the catabolism of fat
in pigs and, when added to feed, it not only
shortens growth time but also increases the
sale price of pork and pig organs. Meat
containing clenbuterol often has a bright red
skin with very little fat. However, approval in
the EU is for bovine and equidae use only.
Maximum residue levels in products of
animal origin are set in Regulation (EC)
2391/2000 at:
Animal species Target tissue MRL
Bovine Kidney 0.5 μg/kg
Liver 0.5 μg/kg
Milk 0.05 μg/kg
Meat .1 μg/kg
Equidae Kidney 0.5 μg/kg
Liver 0.5 μg/kg
Meat 0.1 μg/kg
MoniQA, an EU-funded project connecting global players in the field of food safety and quality,
addresses the melamine crisis and other emerging issues in food safety.
The Case in China
In February 2009, 70 people fell ill after
eating pork products contaminated with
clenbuterol. The victims, all in Guangdong
province, consumed meat bought from
markets in Guangzhou, the provincial capital
of Guangdong, which came from farms in
the neighbouring Hunan province.
Since 1998, there have been at least 19
clenbuterol food poisoning cases in China
affecting more than 1,750 people including
one confirmed death.
In 2006, a series of food borne illnesses in
300 people from Shanghai were associated
with meals containing pork or pig intestines
contaminated with clenbuterol. In June
2006, employees of a hotel in Foshan
suffered from clenbuterol poisoning while
hundreds of workers in a glass factory in
Guangdong Province were also poisoned
by clenbuterol in May 2006.
70 employees at a plastics factory in Jiaxing
City, Zhejiang Province were taken ill with
clenbuterol poisoning after eating pork in the
company cafeteria during November 2008.
Between October 8 and 18 2008, three
people were confirmed to have been
poisoned by clenbuterol from pork in
Page 1 Guangdong.
For further information please visit our website:
www.moniqa.org or contact moniqa@moniqa.org.
A European Commission funded initiative within the Sixth Framework Programme
Topic T5.4.5.1: Quality and safety control strategies for food (NOE)
Contract N0. FOOD-CT-2006-036337
MoniQA Emerging Issues Working Group
One of several working groups within the MoniQA project, the Emerging
Issues Working Group is tasked with keeping a watching brief on new and
emerging issues in food safety on a global scale and undertaking horizon
scanning for potential, as yet unregulated, food contamination hazards.
Previous topics covered have included melamine in Chinese milk and dioxins
in Irish pork and beef.
For specific information about the Emerging Issues Working Group simply
click on http://www.moniqa.org/emerging
To download other MoniQA factsheets visit http://www.moniqa.org/media
References
Barbosa, J. et al. (2005) Food poisoning by clenbutarol in
Portugal. Food additives and Contaminants 22(6): 563-566.
Brambilla, G. (1997). Food poisoning following consumption of
clenbuterol-treated veal in Italy. JAMA 278:635.
Garay, JB. Et al. (1997) Intoxicatión por clenbutarol: Datos
clínicos y analíticos de un brote epidemico en Móstoles. Madrid.
Revista Clinica Espanoca 197: 92-95.
Maistro, S. et al. (1995). Beta blockers to prevent clenbuterol
poisoning. Lancet 346: 180.
Martinez-Navarro, JF. (1990) Food poisoning related to
consumption of illicit β-agonist in liver. Lancet 336:1311.
Pulce, C. et al. (1991) Collective human food poisoning by
clenbutarol residues in veal liver. Veterinary and Human
toxicology 33: 480-481.
In the Media
http://edition.cnn.com/2009/WORLD/as.../china.poisoni
ngs/index.html
http://www.foxnews.com/story/0,2933,500664,00.html
MoniQA Fact Sheet No 3 on:
Clenbuterol
Network of Excellence supported by the European Commission under FP6
Coordinator: Roland Poms (ICC)
Emerging Issues Working Group:
MoniQA and Clenbuterol
MoniQA devotes a share of its resources to emerging (and
previously unforeseen) food safety issues. The case of
clenbuterol, whilst not currently an export issue, is nonetheless of
international importance as cases are not limited to China.
Though not recent, four separate cases of acute food poisoning
in Portugal, involving 50 people, were caused by eating lamb or
beef containing clenbuterol between April 1998 and April 2002
(Barbosa et al. 2005), while similar cases have been reported in
Spain, (Martinez-Navarro 1990; Garay et al. 1997), France (Pulce
et al. 1991) and Italy (Maistro et al. 1995; Brambilla et al. 1997,
2000).
Methods for detection
Clenbuterol is one of a group of drugs called beta 2-agonists,
including mabuterol, terbutaline, carbuterol, cimaterol,
salbutamol, clenpenterol, isoxsuprine, bambuterol and
ractopamine. For control purposes the matrices of choice are
urine and liver. Clenbuterol can be detected using screening
methods based on immunochemical properties, eg. ELISA or
optical biosensors. Alternatively a wide range of beta agonists
can be screened and/or confirmed using liquid chromatography
(LC) coupled to tandem mass spectrometry (MS/MS). When
performing LCMSMS measurements for clenbuterol and a wide
range of beta agonists, it is common for deuterated analogues to
be used as internal standards

[VinhL]

Thuốc Siêu Nạc Ractopamine!!!

Ta Tưởng đâu chỉ có tụi TQ mới chơi thuốc siêu nạc, ai dè đâu Mỷ, Canada, củng chơi, nhưng mà chơi loại ít độc hơn, Ractopamine!!!
Trong khi rất nhiều nước trên thế giới đã cấm thuốc này kể cả TQ, nhưng anh Mỷ, và Canada lại cho sử dụng!!!

Trích:
http://usfoodpolicy.blogspot.ca/2012...e-in-pigs.html

Three views of ractopamine in pigs
Helena Bottemiller this week writes a thorough summary of the international trade controversies over U.S. exports of pork from pigs that have been treated with the growth promoter ractopamine hydrochloride. This animal drug is allowed under U.S. rules, but banned in many other countries, so U.S. trade negotiators have been pressing hard to get other countries to relent and allow small residues of the drug in imported pork.

Bottemiller describes the history of testing by the drug's manufacturer, Elanco, in terms that could leave a reader quite concerned:

The FDA ruled that ractopamine was safe and approved it for pigs in 1999, for cattle in 2003 and turkeys in 2008. As with many drugs, the approval process relied on safety studies conducted by the drug-maker — studies that lie at the heart of the current trade dispute.

Elanco mainly tested animals — mice, rats, monkeys and dogs — to judge how much ractopamine could be safely consumed. Only one human study was used in the safety assessment by Elanco, and among the six healthy young men who participated, one was removed because his heart began racing and pounding abnormally, according to a detailed evaluation of the study by European food safety officials.

When Elanco studied the drug in pigs for its effectiveness, it reported that “no adverse effects were observed for any treatments.” But within a few years of Paylean’s approval, the company received hundreds of reports of sickened pigs from farmers and veterinarians, according to records from the FDA’s Center for Veterinary Medicine.

USDA meat inspectors also reported an increase in the number of “downer pigs” — lame animals unable to walk — in slaughter plants. As a result of the high number of adverse reactions, the FDA requested Elanco add a warning label to the drug, and it did so in 2002.

The company also received a warning letter from the FDA that year for failing to disclose all data about the safety and effectiveness of the drug.

Some of the research literature is available on the USDA website, including this 2003 article by Marchant and colleagues, which indicates why there might be concern.

We found that there were differences in 24h behavioral time budgets, with the ractopamine-fed pigs being more active and alert and taking longer to lie down after being disturbed. However, these differences were only apparent during the first 2 weeks. In contrast, ractopamine pigs remained more difficult to handle over the entire 4-week period. At the end of the 4-week period, they also had higher heart rates than control-fed pigs and higher levels of circulating stress hormones.

We conclude therefore, that feeding ractopamine to pigs does affect behavior and physiology. Pigs that are more difficult to move are more likely to be subjected to rough handling and increased stress during transportation, implying reduced welfare, increased workload for the handlers and, potentially, poorer meat quality. However, for this conclusion to be applicable to the finishing pig population in general, other genetic lines should be tested.

I have been spending some time recently thinking about what makes many Wikipedia articles excellent, and also about the limitations of the free encyclopedia approach. Interestingly, the Wikipedia article on ractopamine is highly technical, as if written by an animal science expert, and generally downplays the safety concern. Although the Wikipedia article includes the Bottemiller article as one recent reference, its summary of the animal safety issue seems to contrast both with her article and with the Marchant article cited above. Here is the section in full:

Target animal safety

Ractopamine is safe for finishing pigs heavier than 240 pounds when administered in the diet at concentrations up to 10 ppm and fed for up to 35 days. However, there was an increase in the number of ractopamine hydrochloride-treated animals exhibiting signs of injury during the final drive to slaughter. (FDA)

I suppose the second sentence captures the animal health issues sufficiently? Of course, the great thing about Wikipedia is that articles are constantly changing and commonly improving.

Trích:
http://www.inspection.gc.ca/animals/.../1331129741124
Approved Brands

PAYLEAN 20 PREMIX contains ractopamine hydrochloride at 20 g/kg (Elanco).
OPTAFLEXX 100 PREMIX contains ractopamine hydrochloride at 100 g/kg (Elanco).

Approved for use

In meal or pellet feed for finishing barrows and gilts and finishing beef cattle and finishing heavy turkeys (toms and hens) only.

Note:

PAYLEAN 20 PREMIX is approved for use in swine (barrows and gilts) and heavy turkey (toms and hens) only.
OPTAFLEXX 100 PREMIX is approved for use in confined finishing beef cattle feeds only.

Approved Claims

For finishing barrows and gilts - Claims 1 and 2.
For confined finishing beef cattle greater than 400 kg body weight - Claims 3 and 4.
For finishing heavy tom turkeys in their last 14 days prior to slaughter - Claim 5.
For finishing heavy hen turkeys in their last 7 to 14 days prior to slaughter - Claim 6.
Claim 1: For increased carcass leanness, increased dressing percent, improved rate of weight gain and improved feed efficiency in finishing barrows and gilts.

Level of Drug: 10 mg/kg (0.001%) of the complete feed.

Directions:

Feed continuously as sole ration to finishing barrows and gilts, that are a minimum 70 kg starting body weight for no longer than six (6) weeks.

Note:

To obtain the performance benefits of ractopamine hydrochloride, diets should contain a minimum of 16% crude protein, or its equivalent obtained by amino acid (0.85-0.95% lysine) fortification. Dietary specifications should be determined in consultation with a recognized swine nutritionist (required on premix and supplement labels, only).

Warning:

Ractopamine hydrochloride is beta-adrenergic agonist. Individuals with cardiovascular disease should exercise special caution to avoid exposure to this medicated feed (required on premix and supplement labels, only).
When mixing and handling this medicated feed, use protective clothing, impervious gloves, and a dust mask. Operators should wash thoroughly with soap and water after handling. If accidental eye contact occurs, immediately rinse thoroughly with water. If irritation persists, seek medical attention (required on premix and supplement labels, only).
Keep out of reach of children (required on premix and supplement labels, only).

Caution:

Do not feed to breeding swine.
Do not feed to pigs intended to be retained for breeding.
Do not feed medicated feeds containing ractopamine hydrochloride for more than six (6) weeks.
The use of ractopamine hydrochloride in pigs finishing over 132 kg body weight has not been studied.
Pigs fed ractopamine hydrochloride may be at increased risk for exhibiting the fatigued or downer pig syndrome particularly when marketed at high body weights. Pig handling methods to reduce the incidence of fatigued or downer pigs should be thoroughly evaluated prior to initiating the use of this medicated feed.
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