Are Farm Antibiotics Destroying Our Health?

When one cattle rancher’s organic herd started dying, he uncovered how antibiotics are making cows sick and obese—and they may be doing the same to us.

Palladium correspondent David Oks has published an in-depth investigation into the effect of antibiotics on animal agriculture and human health. Visiting the ranch of organic cattle rancher Sandy Lewis, Oks learned from Lewis that outside his ranch, it was an industry practice to put antibiotics in the water trough of cattle. A combination of storytelling and research paints a strong case for the negative effects of that may have on human health:

Strange things have been happening to the human body over the last few decades. Our biology has changed, without us quite knowing how or why. Why have human body temperatures declined in the United States over the last 150 years? Or why has the age of first puberty been declining among teenagers since the mid-nineteenth century, from 16.5 years in 1840 to 13 years in 1995?

Or—to take a more troubling and immediate case—why have rates of autism been increasing so dramatically? After having been very rare a few decades prior, the rate has grown from about 1 in 150 children in 2000 to 1 in 44 in 2018, according to the Center for Disease Control. The standard explanation for this increase—changing diagnostic criteria and increased awareness—simply does not explain how sustained the uptick has been, nor does it explain the first-hand accounts of the increase by teachers. In fact, studies have found that changing diagnostic criteria account for only one-fourth of observed increases. Something else is causing the rest.

Or consider something as seemingly straightforward as obesity. In 1975, about 12 percent of American adults were obese; now that figure sits above 40 percent. The standard explanation of the remarkable increase in obesity over the last few decades—the “big two,” more calories and less physical exertion—have an intuitive appeal, but they do not seem to capture the full picture. Between 1999 and 2017, per capita caloric intake among Americans did not change, while the rate of obesity increased by about a third. The increase is so dramatic that a drop-off in physical exertion in so brief a period is unlikely to be the sole explanation, especially since the majority of human energy expenditure is non-behavioral.

Obesity thus remains, in the words of an article in the American Journal of Clinical Nutrition, an “unexplained epidemic.” This is why many scientists have sought to locate contributing factors to the secular increase in obesity, from the decline in cigarette use to increases in atmospheric CO2 levels.

Many mysterious “postmodern disorders” that have become prevalent over the past fifty years may have their origin in a disrupted gut microbiome, which has only had a great amount of attention dedicated to it in the past ten:

The microbiome is invisible to us. Though it plays a role in practically every biological function, it does not have the obvious physical importance of the lungs or the heart. Yet it functions like an organ all its own. It was only a few decades ago that we began to understand just how evolutionarily integrated we, as organisms, are with the microbes that live with us. It is no longer obvious where “we” end and “they” begin; just as we have begun to adopt an ecological view of our relationship with nature, we have begun to understand our bodies as part of a “superorganism,” an ecosystem all its own, with the microbiome playing the role of a “second genome” with 150 times as many unique genes as our own genome. 

The sheer size and diversity of this microscopic world is hard to fathom. There are certainly dominant species in various regions of the body: in the mouth we have Streptococcus, in the gut Bacteroides and Firmicutes; on the skin we have Propionibacterium, Corynebacterium, and Staphylococcus. But there is little unity in these microbial “kingdoms.” They are closer to patchworks of small principalities, where a few days of walking lands you somewhere with a different language. The microbes that live at the duodenum, the start of the small intestine, are very different from those of the rectum; on average, left and right hands on the same individual share just 17 percent of phylotypes. 

Crucially, a wide variety of conditions including the “postmodern” ones like autism, autoimmune disorders, and obesity—Blaser originated the “postmodern” framing in his 2014 book Missing Microbes—are accompanied by changes in the microbiome. Study after study has found that obese people tend to have severe dysbiosis in their gut microbiomes, with a significant reduction in the prevalence of Bacteroidetes and a proportional increase in the abundance of Firmicutes, another bacteria. Legions of studies have found similar relationships for autism,  autoimmune diabetes and other autoimmune conditions like irritable bowel syndrome, for asthma, for allergies, and for all the other conditions that constitute the postmodern disease package.

One of the ways humans ingest antibiotics outside of prescribed usage is through the food we eat and the water we drink. The usage of antibiotics in animal agriculture began in the 1940s, after it was discovered that chickens given chlortetracycline would grow larger.

The discovery set off a revolution in how animals were raised. The New York Times announced that the drug “has been found to be one of the greatest growth-promoting substances so far to be discovered;” antibiotics in animal feed soon became a major research focus at nearly every drug company. “Here is good news for both farmers and meat eaters,” Fortune magazine announced in 1952: “antibiotics provide more meat with less feed.” By 1955, farmers were already treating their animals with 490,000 pounds of antibiotics a year.

…

All of this put other animal protein products—particularly beef and pork—on the defensive. By the mid-1970s, per capita beef consumption entered a long decline, while pork consumption plateaued. By 1992, Americans ate more chicken per capita than they did beef for the first time.

This meant that beef production, too, would have to be made more efficient and cost-effective—“chickenized,” in the parlance of some farmers. But cows were a much more challenging terrain for this type of Fordist intensification than chickens. Small, docile, fast-maturing, and slaughtered without much fuss, chickens are the perfect cogs for a highly optimized food production system.

…

As with chickens, the biological effects on cows were significant. The year that monensin was licensed, the average weight of cows at slaughter was 1,047 pounds; by 2005, it had grown thirty percent, to 1,369 pounds. By 2017, American cattle producers used about 171 milligrams of antibiotic per kilogram of livestock—four times as much as in France, and six times as much as in the United Kingdom.

While the use of antibiotics for growth promotion was finally prohibited by the FDA in 2017, there are “motorway veterinarians” willing to prescribe antibiotics, sometimes without even seeing the cows. Even beef that we are assured is antibiotic-free can be anything but: “One study in Science found that 42 percent of lots that were certified by the Department of Agriculture as ‘Raised Without Antibiotics’ actually contained cattle that had been given antibiotics, with five percent of lots being composed entirely of cattle raised on antibiotics.”

There is much more available research on the direct effects of antibiotics on animal health than on humans:

The effects of this antibiotic pollution in the natural world appear to be profound. The leakage of antibiotics into natural environments alters animal biology in grotesque ways: sub-medical concentrations of antibiotics have been shown to cause severe physical deformations in zebrafish, like yolk sac edema, as well as in amphibians like the Western clawed frog. Because the drugs have an effect on gene expression, the deformations extend into development and behavior as well: a study of the small crustacean Daphnia magna found that tetracycline impacted the general stress response and metabolism.

Most worryingly, the effect was multigenerational, extending from parent to child—and carried over even after tetracycline was removed from the ecosystem. It is not surprising that the introduction of antibiotics into an aquatic environment leads to reduced fertility and increased mortality. Lewis believes that antibiotics are responsible for the insect die-offs seen in industrialized countries: the antibiotic rifampin resulted in “prolonged reductions in longevity and fecundity” among two termite species, with similar effects shown with bumblebees’ exposure to antibiotics. He points to the richness of insect life on his farm as a useful contrast.

Restoring human health will mean finding a way to care for the smallest living things—the species of bacteria that inhabit the gut microbiomes of us and the animals we share the Earth with.

---

Here’s what’s been on the front page lately:

Are Farm Antibiotics Destroying Our Health? by David Oks. When one cattle rancher’s organic herd started dying, he uncovered how antibiotics are making cows sick and obese—and they may be doing the same to us.

Political Academia With Stephen Hsu. Researching the frontiers of genomics, modeling uncertainty, and managing a university have taught Professor Steve Hsu that scientific questions aren't the only kind that scientists have to answer.

On the State of the Art With Laibach. The enigmatic Slovenian music group speaks with Samo Burja about the Apocalypse, artificial intelligence, and why Europe is still under occupation.

Palladium Podcast 83: Tea Törmänen and Marco Visscher on Ecomodernism. Tea Törmänen and Marco Visscher join Ash Milton to discuss their recent article and the difference between degrowth and ecomodernism.

Why We Need the Center for Strategic Translation by Tanner Greer. The American Governance Foundation is launching a new institution to help American decision makers understand China.

That’s all for now.