Antibiotics and Hormones in Beef

by Brian Dunning
May 3, 2016

Today we're headed out to the farm, to have a look at that poster child of so many controversies: the beef cow. For better or worse, beef feeds many people around the world, and its production has become a massive industrial engine. Today we're going to focus on just one small part of that engine: the use of drugs in these cattle, for veterinary, growth, or other purposes. It's a practice that has exploded onto the pop foodie scene, and been portrayed as both a terrible danger to humans and an animal rights catastrophe, especially by the organic and all-natural lobbies. Some trumpet the perils of eating beef loaded with hormones; others fear the creation of antibiotic-resistant superbugs. What are the true facts of drugs in beef, and should you be concerned about them?

It's important to preface this topic with some acknowledgements: there are some very good reasons why beef is, strategically, a bad food product. Meat production, even as a percentage of the totality of all livestock industries, has a huge environmental impact. About a quarter of the world's land is used for grazing. A third of all planted crops worldwide go to feed livestock. It's the major driver of deforestation. A tenth of all fresh water goes to support livestock and their feed crops. A shocking 15% of greenhouse gases come from livestock. All of that produces polluted waste water and runoff, and consumes energy to operate. The beef industry truly is the big bully who grabs far more than his share of resources. However, this imbalance is what the market has chosen.

I point out these facts as a dedicated meat lover. I will eat filet mignons all day long. Like everyone, I strike a balance between the things I enjoy and their cost. But just as I don't allow my love of steak to cloud my awareness of the environmental impact of beef, neither should the beef opponents make up untrue facts to poison the well and portray beef as even worse than it is. As with many Skeptoid topics, a poor understanding of the facts of a problem lead to poor solutions. Whether you want to eat steak all day long, or you want it abolished from the food system, it is in your best interest to have a correct understanding of the facts, including the pros and cons of using antibiotics and hormones in the husbandry of beef cattle.

The most common beliefs among the general public are twofold: first, that growth hormones are given to cattle to make them grow faster, and that these hormones might cause endocrine problems in the people who consume the meat; and second, that antibiotics are given to cattle because it's cheaper than keeping them in clean, humane conditions, and these antibiotics represent an overuse that leads to resistant superbugs who present a danger to human health. As in so many subjects, there are elements of truth to this, elements of fiction, and parts of it that are misunderstood and sound a lot scarier than they really are.

Let's start with the antibiotic resistance. Anytime antibiotics are used to fight bacteria, there is usually a small number of those bacteria who happen to be resistant to that antibiotic. When that antibiotic is used a lot, the resistant bacteria gradually become the majority, and then we have a real problem: an infection that we can't fight. We already see this happening in medicine. It's an arms race between molecular biologists and evolving bacteria strains. The best defense is to always use antibiotics as infrequently as possible.

But cattle get sick, just like people do. In the cattle ranching industry, cattle are the industry; they are the valuable asset. We don't let them get sick and die if we can help it. So veterinarians are obviously a big part of cattle ranching. And antibiotics are, just like in humans, one of the essential tools to fight infections.

One concern activists have raised about this treatment is that resistant bacteria in the beef might make it all the way through the production process, end up in someone's steak, and give that person a bacterial infection. While it's true that a cow so treated might conceivably end up with a resistant infection, such an infection could only pose a threat to the consumer if the beef was consumed raw. This is the case with eating any animal meat, and always has been and always will be. At least if the cow had been treated, fewer bacteria would remain. Risk of contamination is one important reason why, thousands of years ago, we learned to cook our meat. Cook your beef (and any other meat) like a civilized person, and you don't have a significant concern about bacteria.

Some people are also concerned that even if no bacteria are making it through, there might be residue from the antibiotic that stays in the beef, gets eaten by people, and then promotes the growth of resistant bacteria in those people. Fortunately, this does not happen at all. Antibiotics are metabolized very rapidly by humans and animals. That's why your doctor gives you a bottle and you have to take several pills a day; the pharmacokinetics are such that there's not enough left in your system after only a few hours or days at the most. When cattle are treated with antibiotics, these pharmacokinetics are the same. But we don't take any risks here. Cattle given antibiotics are subject to what's called a withdrawal time, a waiting period where that cow cannot go into food production until we're sure there are no antibiotics left in its system. Depending on what drug is given, this withdrawal time is anywhere from 0 to 60 days. By the time any cow goes into food production, there's no antibiotic in its system.

But we take it even one step further than that. Nearly all ranchers in the United States follow the Beef Quality Assurance program, a set of guidelines for the safest practical beef production. One of these rules is that cattle should never be treated with antibiotics that are also used in human healthcare. This guarantees that even if a cow did somehow slip through the cracks and went into food production before all the antibiotics had gone through its system, and even if a person did consume that beef and got some of that antibiotic into their system, there's no way it could contribute to a population of bacteria resistant to any type of antibiotic that person might be prescribed.

The Beef Quality Assurance guidelines also recommend treating the fewest number of animals necessary. This one is easy for ranchers to follow, since antibiotics are expensive and nobody wants to spend money they don't have to spend.

Never say never, but the combination of the safeguards required by industry and the science of metabolism mean that the chances of beef production resulting in an outbreak of antibiotic resistant bacteria dangerous to humans are virtually nonexistent. What's far more likely, and what actually does happen in the real world, is bacterial contamination of meat and other foods from packaging and handling. Clean and cook your food well, and veterinary treatment of cattle with antibiotics is a concern that you can realistically cross off your list.

The other common belief about drugs given to cattle has to do with growth hormones. It is true that both natural and synthetic versions of estrogen, progesterone, and testosterone are used in most beef cattle in most countries. These are preferred because they occur naturally in cattle, just as they do in humans, so they're not a foreign substance. They are essentially the same thing as the anabolic steroids used by some bodybuilders. The main difference is the dose. A 100kg bodybuilder will sometimes take more than 1,000mg each week, while a 900kg beef cow is given a single 200mg pellet implanted under the skin of the ear which dissolves over a period of 100 to 365 days, depending on the type. (Note on these dosage ballparks: bodybuilders' doses vary wildly, and there are smaller doses than this for certain cattle.) Do the math. It's common for a human bodybuilder to take 650 times the maximum allowable dose that ranchers give to beef cattle.

In broad strokes, this is the long and the short of the reasoning behind why there's no need for concern about hormones given to beef. We give cattle very small doses, even smaller than the doses given to postmenopausal women; and it's a compound naturally produced the body anyway. That dose is not up to the ranchers to ratchet up if they want; it's established by law. Cattle on this regimen have a zero-day withdrawal time, meaning they are safe for food production at any time, as the level of hormone in the meat is well below maximum safe levels. The variation in naturally occurring hormone levels in different kinds of meat — fish, fowl, pork, beef — and even in cattle of different ages and breeds — is much greater than the difference between treated and untreated cattle.

Even if — by some process outside normal beef production — an excess level of hormones did get into the beef, some of it would be broken down by cooking, and most of what remained would not survive digestion. Hormones taken orally get metabolized, mostly by the intestines and the liver. This is why when we take hormones, they're often delivered via a patch or an implant or some other mechanism that bypasses the digestive system. It's also the reason they're given to livestock via an implant.

So unless you are eating a competitive bodybuilder — and in fact, not even eating him, but putting a sample of his muscle tissue under your skin as an implant — there is no plausible way that you can suffer any kind of an endocrine problem from eating normally produced beef.

I'll go a step further. The anti-beef lobby should, if anything, embrace the use of hormones on beef, because it reduces the time needed to bring them to market. This has a butterfly effect that improves all of those many impacts caused by the beef industry.

Beef has been a staple throughout human history, yet its production has seen only limited improvement in efficiency over the centuries. There are alternate red meats with a far lower environmental impact (kangaroo is one of which I'm especially fond), and obviously there are alternate diets that don't include red meat at all. There are fine fact-based reasons why we should look seriously into moving away from beef from cattle, and these are ones that the anti-beef lobby should focus on. Claiming harm to human consumers from drugs given to beef cattle simply doesn't stand up to scrutiny as a valid argument.

By Brian Dunning
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