Tuesday, June 7, 2011

The Egregious Case of Escherichia coli

I read this article in the New York Times and pondered the following quote by a German girl: “[E. coli is] a big conversation issue among my friends,” she said. “Some are no longer eating salads. Others are ignoring the medical recommendations. As for myself, frankly, people have died. For me, that’s the bottom line. I no longer eat salads. But then again, this E. coli strain could be in milk, meat, whatever. It is very worrying. I have no idea what to eat anymore.” For the Europeans now battling an outbreak of E. coli O104:H4 sickness and even death by this pathogen are very real fears by both vegetable farmers and non-ag consumers. Lost crops and lost revenues also seriously afflict the vegetable farmers. Everyone from consumers to producers shares an equal magnitude of concern for food safety.

In the United States, Escherichia coli O157:H7 instigates 73,000 cases, 2000 hospitalizations and 60 deaths each year (Food Seminars International, 2011). I certainly find it unfortunate that eating raw or undercooked foods poses a risk to my health, but among all the other risks I juggle in my daily life, I worry the least about my food. I make the choice to trust that my food in the U.S., after passing numerous checkpoints of vigilant FDA and USDA workers, is safe (See Industry Guide to Minimize Microbial Food Safety Hazards for Fresh Fruits and Vegetables and Consumers' Guide to Safe Handling of Raw Produce and Fresh-Squeezed Fruit and Vegetable Juices ).

Honestly, though, when you think of E. coli, doesn’t beef come to mind first? This is probably because the pathogen’s fame debuted in a hamburger served at Jack in the Box in 1993. Since then, the Checkoff dollars from beef cattlemen (a program that extracts $1 a head in every cattle sale) have overwhelmed the scientific community with over $30 million for beef safety research. Also, every year the beef industry spends $550 million to validate and conduct their safety control methods (See the Cattlemen’s Stewardship Review). E. coli is now primarily a fresh produce issue.

What I find frustrating is that there have been some claims (namely the ones made in The Omnivore’s Dilemma by Michael Pollan, and the film Food, Inc.) that grass-finished beef is “safer” than grain-finished beef because the grass-based diet does not culture an optimal, acidic, E. coli environment like a grain-based diet does. FALSE.

What a naïvely dangerous claim to make, and on such faulty science! These two media venues have championed the “junk science” of a pilot study conducted at Cornell testing the “Effect of grain-feeding on the numbers of E. coli in the colonic digesta of cattle (a) and their survival of an acid shock (b) (pH 2.0, 1h). Cattle (three animals, three observations per animal) were fed three ratios of timothy hay to grain (10:90, 55:45, 100:0).” (Russell et al., 2001, the review paper that was able to publish unpublishable data). Look back at the description I gave. Three cattle on three diets? Three observations? That’s like someone assigning you, me, and Dirk Nowitzki Rice Krispies, Cocoa Puffs, and Frosted Flakes, respectively, and after three basketball games concluding that Frosted Flakes is the best cereal for enhancing athleticism. Okay, an extreme example, but you get my point in that without having sufficient replication (a large sample population), it’s not scientific.

If warding off E. coli were as simple as feeding cattle hay, wouldn’t the entire beef industry follow suit? Quite to the contrary, it was found by a referee-journal publication in Calloway et al. (2009)  that it is in fact when the rumen pH is highest (least acidic, especially when the rumen is empty or sometimes when it is full of a high-fiber, grain-free diet) that E. coli proliferate. Because of this, cattle feeders have changed their fasting protocols before slaughter.

I’m going to wash my American-grown vegetables before stacking them on my 160ºF hamburger patty tonight…and I’ll have a salad on the side. What do you Think?


  1. It always surprises me how much media are based on "research" that does not come close to following proper statistics. What is even more sad is that these media dictate the actions of the majority of the advocacy groups and a decent portion of America. I never thought about your argument with anti-bacterial soaps and cleaners around the house, I will add that into my arsenal. Keep up the good work.

  2. Cassie,

    I love what you are doing here. We need more people like you telling facts & truths about ag! Look forward to reading/learning more from you down the road!

    Jamie May