May 25, 2018
Farm chicken in a barn, eating from an automatic feeder
Be Well

Antibiotics in Farm Animals: Enough!

by John Swartzberg, M.D.  

If you eat meat, as I do on occasion, you may unknowingly be contributing to the growing public health crisis of antibiotic resistance. That’s because antibiotics are used in conventional meat and poultry production not only to treat sick animals (an acceptable practice), but also inappropriately to prevent disease and promote growth. In fact, the amount of antibiotics sold in the U.S. for use in livestock is four times higher than the amount sold for use in people. The result is that bacteria become resistant to the antibiotics, posing a threat to humans (and other animals) who depend on these drugs to fight infections.

The Wellness Letter recently spoke with Maryn McKenna—an investigative journalist who specializes in infectious diseases, global health, and food policy—about the history of antibiotics in agriculture and what is being done to curb their overuse. She is the author of several books including, most recently, Big Chicken: The Incredible Story of How Antibiotics Created Modern Agriculture and Changed the Way the World Eats. I learned a lot and wanted to share some of what was discussed.

According to McKenna, the use of antibiotics on farms can be traced to two things, starting during World War II. First, the recently developed antibiotic penicillin became a lifesaver on the battlefields. The war also drove the meat industry to increase its production to feed military personnel all over the world. After the war ended, however, when faced with a meat-production overcapacity, producers had to figure out a way to keep the industry from collapsing. One way was to produce meat more cheaply by switching to a cheaper feed—from fishmeal to grains in the case of chicken. But animals don’t do so well on cheap feed, so the industry had to develop a supplement to keep the animals healthy.

A scientist working for one of the early producers of antibiotics was tasked with creating a feed supplement for poultry. He decided to use what was left over after antibiotics are made—a sticky mass of dead bacteria and the remaining carbohydrates that the bacteria didn’t consume. These leftovers contain tiny doses of antibiotics, which turned out to speed growth in the chickens.

Needless to say, there was great enthusiasm for the feed supplements (that is, growth promoters). Because they fattened chickens more quickly, farmers could sell them at a younger age, increasing profit. Sales of the feed supplements soared.

But almost immediately came warnings from veterinarians that these feed supplements would promote antibiotic resistance. They were ignored. The first-ever cases of antibiotic-resistant foodborne illnesses arising from agricultural use appeared in the mid-1950s.

Is anything being done to address the problem? Yes. An FDA ban on using antibiotics as growth promoters went into effect in the U.S. in January 2017. (In Europe, antibiotic growth promoters have not been allowed since 2006.) Farmers and ranchers now also need a prescription from a vet to get antibiotics. But because the new regulations ban only the use of the drugs to help animals gain weight, there’s concern that meat producers will use the same amount of antibiotics, claiming it to be all for disease prevention instead.

Other encouraging news is that U.S. chicken producers, in particular, are raising more ABF (antibiotic free) or NAE (no antibiotics ever) birds to meet the needs of fast-food chains that are voluntarily committing to antibiotic-free policies in response to increasing consumer demand. As McKenna said: “That is a real development, not spin, and it has changed the industry . . . . The challenge will be whether the pork and cattle industries can follow chicken. Those are more complicated, longer-lived animals that get moved around more in their lifetimes, and thus are more exposed to disease risks. Taking them antibiotic-free will be challenging, but it must be done.”

According to the most recent data, sales of farm antibiotics de­­creased 10 percent between 2015 and 2016—before the new ban on growth promoters even went into effect. Time will tell if the current downward trend continues. I hope for all our sakes that it does. In the meantime, you can be part of the antibiotic-free movement by buying meat and poultry raised without antibiotics (though you’ll probably pay a higher price) and by supporting restaurants that are going antibiotic free. Consumer Reports provides scorecards for 25 fast-food restaurants regarding their antibiotic-use policies. As of late 2017, more than half had policies in place that will help reduce antibiotics used in meat and poultry production.

This article first appeared in the UC Berkeley Wellness Letter.

Also see Are Antibiotics Making Us Fat?