Risks of Clenbuterol! No more than 1.25 mg per kg body weight

Taiwan-US relations have once again hit a freezing point over beef containing ractopamine (commonly known as "lean meat powder"). What people are most concerned about now is: What is the safe range for the human body to accidentally ingest ractopamine? In fact, U.S. federal regulations have clearly defined some standards. For example, a 50-kilogram person should not consume more than 6.25 mg (0.06 g) of ractopamine per day. However, this content is difficult to calculate, so experts recommend avoiding eating internal organs that are prone to accumulation of this substance as much as possible to minimize the risk.

As early as 1999, the U.S. Food and Drug Administration (FDA) allowed livestock producers to use feed containing ractopamine, but Taiwan issued a clear ban on the import of meat containing ractopamine residues in 2006. The two sides have been deadlocked for many years, leaving many people still unaware of what side effects will occur after eating it.

"Ractopamine". (Photo taken from http://www.best-b2b.com/)

As the name suggests, Clenbuterol is a beta-adrenoceptor agonist that makes livestock grow lean meat and reduce fat after eating it. According to information provided by Wikipedia, for a 90-pound (40.82-kilogram) pig that eats feed containing 20 mg (parts per million, ppm) of Clenbuterol, muscle protein will increase by 24% and fat will decrease by 34%. Not only will the breeding speed be greatly increased, but its residues will also mostly be excreted in urine and feces, with only a small amount remaining in the animal's body. Therefore, the United States stipulates that meat products must not contain more than 50 micrograms (parts per billion, ppb) of ractopamine, while Japan sets the upper limit at 10 micrograms.

Eating ractopamine will gradually accumulate in the body. Unless the meat is consumed in large quantities every day, it will not have an immediate impact on health and will not cause cancer. However, mutations in lymphocyte chromosomes have been observed in past experiments. In addition, within 4 hours of ingesting ractopamine, the heart rate will change, the systolic blood pressure will accelerate, but the diastolic blood pressure will remain unchanged; some people with more sensitive constitutions may even experience tremors in the limbs due to an imbalance between the slow-twitch and fast-twitch muscle groups. Clinical experiments have also confirmed that ractopamine will stimulate the human central nervous system, causing negative emotions such as anxiety, worry and depression.

Section 21 of the U.S. Code of Federal Regulations, No. 556.570, states that ractopamine does accumulate in specific parts of the animal's body, but does not pose a potential danger as long as it does not exceed a certain concentration. For example, the upper limit in muscle is 0.25 mg, and in the liver, kidney and fat it is 0.75, 1.5 and 1.5 mg respectively. In addition, consumers must take no more than 1.25 mg per kilogram of body weight per day as a baseline for intake.