This paper reflects the research and thoughts of a student at the time the paper was written for a course at Bryn Mawr College. Like other materials on Serendip, it is not intended to be "authoritative" but rather to help others further develop their own explorations. Web links were active as of the time the paper was posted but are not updated.
2000 First Web Report
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.
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
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
| Back to Biology 103 | Back to Biology | Back to Serendip |