Grass-Fed Beef Have Reduced E. coli Presence
The fact that grass-fed beef helps reduce the incidence of extremely injurious E. coli is actually really old news. Scientists have known since 1998 that cattle fed on grass, even if just for the last few days before slaughter, have severely reduce the rates of E. coli contamination. Michael Pollan details the causal linkage between corn-fed cows and the increased incidence of human E. coli poisoning:
Most of the microbes that reside in the gut of a cow and find their way into our food get killed off by the strong acids in our stomachs, since they evolved to live in the neutral pH environment of the rumen. But the rumen of a corn-fed feedlot steer is nearly as acidic as our own, and in this new, man-made environment new acid-resisitant strains of E. coil, of which 0157:H7 is one, have evolved–yet another creature recruited by nature to absorb the excess biomass coming off the Farm Belt. The problem with these bugs is that they can shake off the acid bath in our stomachs–and then go on to kill us. By acidifying the rumen with corn we’ve broken down one of our food chain’s most important barriers to infection. Yet another solution turned into a problem.
We’ve recently discovered that this process of acidification can be reversed, and that doing so can greatly diminish the threat from E. coli 0157:H7. Jim Russell, a USDA microbiologist on the faculty at Cornell, has found that switching a cow’s diet form corn to grass or hay for a few days prior to slaughter reduced the population of E. coli 0157:H7 in the animal’s gut by as much as 80 percent. But such a solution (Grass?!) is considered wildly impractical by the cattle industry and (therefore) by the USDA. Their preferred solution for dealing with bacterial contamination is irradiation–essentially, to try to sterilize the manure getting into the meat.
Evidently, grass and hay are the cow’s Tums:
If cattle are going to be continually raised on food they have not evolved to eat, the USDA should at least impose measures that eliminate unnecessary risk. According to Russell and Donald H. Beermann, Cornell professor of animal science, the switch to grass or hay could be implemented “with minimal expense and inconvenience to feedlot operators.” In addition, it would affect neither carcass size nor meat quality (link). If it is so cheap and easy, why do meat processors still chose to rely on imperfect irradiation?
Change is still change. It’s risky. And, since the feedlot operators have not seen dire repercussions from E. coli scares, there is little impetus to change besides a sense of goodwill. Therefore, it is up to the USDA to create and enforce a mandatory diet change. Unfortunately, given the revolving door between industry lobbyists and government officials, it is not surprising that the USDA has yet to initiate such legislation (see 99-102 of Food Politics).
Barack Obama was elected on a message of hope and change, and he recently ordered a top-to-bottom review of the USDA. Those two mandates need to come together if lives are to be saved.
March 2, 2009
Tags: change, cows, farmers, food safety, Health, Michael Pollan, USDA Posted in: Health, Politics, Science & Technology
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