Poking around the Blogosphere and Twitterverse, I have encountered on multiple occurrences statements and claims promulgating the idea that grass fed beef can be handled differently than “conventional” beef because it’s “safer.” I tend to be a worrywart when it comes to this idea, that somehow “grass-fed beef doesn’t harbor E. coli.” That fallacy has been construed by some to communicate:
- Grass-fed ground beef can be safely consumed when cooked rare (false)
- Grass-fed beef has no E. coli (false)
- Pets can safely eat raw grass-fed beef (false)
- Other similar ideas…
A Few Studies finding E. coli in grass-fed cattle:
- In feces, 10% of grass-fed cattle and 15% of feedlot cattle harbored E. coli O157:H7 – Journal Applied Microbilogy, 97:2, 362-370
- At weaning (off pasture), at least one calf shed E. coli O157:H7 on 87% of farms – Epidemiology and Infection, 123, 291-298
- E. coli O157:H7 was excreted from cattle in 16% of pastured herds – Epidemiology and Infection, 133, 199-207
The reality is: E. coli O157:H7 can be isolated from the feces of grass-fed cattle, and is possible that the pathogen could be transferred to the carcass (likely via hide contamination). Is the incidence lower compared with feedlot beef? Sometimes. Is it absolutely absent? No. And the kicker of all this is that those people promoting the notion that grass-fed beef is effectively “guaranteeably safe” are generally people who want to see the safety of beef improved (just like the rest of us). Best food safety practices for “conventional” beef apply unchanged to grass-fed beef. These practices include: cooking ground beef to 160°F, use a meat thermometer to assess doneness because color is not an accurate indicator of doneness, prevent cross-contamination in the kitchen, at minimum wash the plate that held raw beef before placing cooked beef on it, and the list continues.
Why or how can beef become contaminated by E. coli O157:H7? Contrary to popular imagery, the most likely point of possible contamination is not a pierced intestine dripping feces onto fresh meat (no). Rather, it most likely happens during hide removal. We are amid deer season, and perhaps the best way to explain why/how this can happen is to review skinning a deer. To remove a hide, the hide must be punctured, which may translocate whatever was on the hide’s surface into what is below — meat. Ever skin a deer shank? Though you likely have not, I hope you can ask someone who has done this what it is like, and whether or not hair or dirt can be transferred to the carcass. The answer is unequivocally – yes, it can. How a beef hide is removed from the carcass is very similar to how one would skin a deer. The difference with beef, however, is that a series of hurdles is applied, such as hot water washes, steam pasteurization, and mild acid washes to help ensure safety, not to mention elements of the inspection process. Yet as we are all aware, some “stuff” still gets through the system. It is as true of “conventional” beef as it is grass-fed beef.
Those who state that “the risk for E. coli in grass-fed beef is lower than for other beef” may be correct, and are certainly much more accurate than those who state that “grass-fed beef is E. coli-free.” The messages are entirely different. At least one communicates that there is still a “risk,” and reinforces that there is no “silver-bullet” for ensuring beef safety. Albeit, the closest thing we have to this “silver-bullet” involves cobalt 60 and a lot of concrete. When it comes to beef safety, one thing is concrete, though — it all needs to be safely handled, and appropriately and adequately cooked, to ensure the destruction of any possible pathogens. Complacency and a sense of false security is a very “un-foodsafe” mindset.
A body of literature on the subjects of grass feeding, “conventional” feeding, and E. coli O157:H7 exists and much can be accessed via web searches.