Tox Tuesday: Banned substance tested for in both athletes and meat

March 20, 2018

Clenbuterol is a decongestant and bronchodilator that is well known as a performance-enhancing drug, but is also hot on the black market for a different purpose: fattening up farm animals before slaughter.

One famous Mexican boxer recently tested positive for the banned substance, but claims that he didn’t intentionally take the performance-enhancing drug — rather, that clenbuterol-tainted meat is responsible for the results.

The boxer, Canelo Alvarez, was tested by the Voluntary Anti-Doping Association (VADA) in anticipation of an upcoming rematch against unified middleweight world champ Gennady Golovkin. Both samples Alvarez submitted tested positive for clenbuterol.

β2 agonists such as clenbuterol are sometimes taken by athletes to increase muscle performance and metabolism, decreasing body fat. Clenbuterol is like the epinephrine injected by sufferers of severe allergic reactions, but also has strong stimulant and thermogenic effects. It increases aerobic capacity, central nervous system stimulation, blood pressure and oxygen transportation, all of which can help an athlete. Medically, it’s sometimes used by people with chronic breathing disorders like asthma, but is illegal in many countries.

Some countries permit clenbuterol to be used to treat respiratory issues in horses, but it’s sometimes illegally given to farm animals to make them bigger before slaughter, or to make their meat appear fresher than it really is.

The problem is, residues of clenbuterol can show up in meat, which can cause health issues in humans who consume it. For this reason, many countries prohibit its usage in animals destined for meat. Clenbuterol-tainted meat can cause heart palpitations, muscle tremors, dizziness, nausea, vomiting, fever, and chills. Long term exposure may cause tumors, and poses risks to people with high blood pressure or diabetes.

In the recent boxing case, Alvarez blames his own positive tests on tainted meat. This is far from the first time such a case has come up. In recent years, athletes from or who have visited Mexico have blamed their failed drug tests on clenbuterol-tainted meat. According to the Sports Medicine Research and Testing Laboratory’s director, Daniel Eichner, the values from Alvarez’s tests match the expected range of meat contamination.

Alvarez has gone on to test negative for clenbuterol after a third drug test was administered by VADA. It’s impossible to determine whether the boxer intentionally took the substance or not, and the Nevada State Athletic Commission has not issued a decision regarding whether his fight with Golovkin will go on.

Neogen offers products both for testing for clenbuterol and other growth promoters in meat, and also for detection in human urine, blood or oral fluid.

Category: Food Safety, Toxicology