For related articles and more information, please visit OCA’s Food Safety Research Center page.

CUERNAVACA, Mexico – Fourteen years after Mexico banned cattle ranchers from using a growth enhancer called clenbuterol, statistics from the federal agency responsible for meat quality show that some Mexican cattlemen just can’t give it up.

That’s especially true in the states surrounding Mexico City, where thousands of American retirees have settled and thousands of American tourists visit. Testing in the state of Guanajuato, home to the popular retiree center of San Miguel de Allende, found 30 percent of 175 samples tested were tainted with clenbuterol, which can cause heart palpitations, tremors, dizziness, nausea and increased anxiety in people who ingest it. Symptoms generally pass within two to six days.

Outside of a cluster of states in central Mexico, it appears unlikely that foreign tourists would feel ill effects from eating beef. Most major supermarkets and restaurant chains buy their beef from 117 large private slaughterhouses with on-site federal inspectors who conduct rigorous testing of meat for contamination. Northern Mexico and coastal resorts also appear free from the taint.

But that inspection regimen falls apart in a half-dozen Mexican states surrounding the capital, where cattlemen often sell their beef to smaller slaughterhouses operated by municipalities. That beef generally turns up at street markets, where poorer Mexican consumers shop, then goes to sidewalk taco stands, mom-and-pop restaurants and into Mexican homes.

In many ways, tainted meat is emblematic of broader problems in Mexico, where rigorous laws exist but corruption often means enforcement is lax to non-existent. Ranchers in central Mexico spike their feed with illegal clenbuterol because it bulks beef cattle up and increases their profits, but the government makes only modest attempts to halt the practice. When it does act, the result often is simply to push lawbreakers to new locations.

Meanwhile, consumers seem to prefer the leaner, pinkish meat clenbuterol produces, either unaware or unconcerned of the health risks – a situation encouraged by authorities who downplay the risk of falling ill, alleging that health statistics show that out of every million Mexicans, only one gets sick each year from the synthetic compound.