Amid growing concerns about the overuse of antibiotics in farm animals, Burger King has joined the list of fast food chains that will scale back on the use of drugs that are medically important to human beings.

For livestock farmers, these antibiotics can help produce chickens that yield more meat. Unfortunately, the continuous low-dose use of antibiotics also contributes to the development of antibiotic-resistant bacteria, rendering these very drugs less-effective (or useless) for treatment of actual disease.

In its latest sustainability report [PDF], Restaurant Brands International, parent company to both BK and Tim Hortons, vowed to cut the use of antibiotics in the chicken supply for both restaurant chains by the end of 2018.

The company, which purchased Popeyes earlier this year, said that it plans to roll out the new policy at all of its brands, but did not provide a timeframe for the change.

“We recognize that antibiotics play an important and delicate role in animal wellbeing and human health,” the company said, noting that it would work with its supply chain partners to support and implementing changes.

The company said that it began work toward eliminating the use of antibiotics by creating a partnership with the University of Guelph in 2012 to establish the Tim Hortons Sustainable Food Management fund.

In a recent report card on restaurants’ antibiotics policies, Burger King was one of 16 chains that scored a failing grade. Tim Hortons and Popeyes were not on the list.

Earlier this year, our colleagues at Consumers Union gathered more than 125,000 signatures on a petition calling on Burger King and others to finally adopt policies reducing their use of antibiotics. Today, CU is applauding KFC’s decision, calling it “chicken done right.”

A growing number of restaurants have realized that this risk is too big a price to pay for heavier chickens. McDonald’s, Wendy’s, Chick fil-A, KFC, Taco Bell and Pizza Hut have all already made some commitment to sourcing chickens that are raised with fewer, or no, antibiotics.

In fact, the Natural Resources Defense Council said that with today’s announcement 11 of the top 15 chains in the U.S. have now committed to some level of responsible antibiotics use for their chicken supplies.

The NDRC applauded Restaurant Brand’s announcement.

“We have officially passed the tipping point on antibiotics use in chicken served by the U.S. fast food industry,” Lena Brook, Food Policy Advocate at the Natural Resources Defense Council. “With this commitment, Burger King and Tim Hortons are helping to keep our lifesaving drugs working when sick people need them.”

The organization noted that the next target will be to curb antibiotics use in beef and pork.

Antibiotics used on farm animals account for the overwhelming majority of all antibiotics sold in the U.S., and sales have continued to increase even after drug companies volunteered to stop marketing these drugs for growth-promotion purposes.

Reducing antibiotic overuse in chickens is important, but only represents one facet of the issue. Fast food chains are already feeling the pressure to curb antibiotics in the beef and pork they buy, but that change — if it happens — will take more time. A chicken now reaches market weight in less than two months, while beef cattle may need up to two years.

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