Low Risk of E.Coli

The type of E. coli bacteria responsible for most cases of human illness and death is called “E. coli 0157:H7.  Some experts believe this toxic E. coli evolved in cattle that were fed high-grain diets. Every year, hundreds of thousands of pounds of beef products are recalled. One of the largest recalls to date took place in October 2007 when Topps Meat company recalled 21.7 million pounds of hamburger because of potential E. coli contamination.

A study by Cornell University has determined that grass-fed animals have far fewer E. coli (approx. 300 times less) than their grain fed counterparts. Also in the same study, the amount of E. coli they do have is much less likely to survive our first line defense against infection, stomach acid. This is because feeding cattle grain makes their digestive tract abnormally acid, and over time, the ‘bad E. coli’ has become acid-resistant . So if we ingest them in our food a large number of them can potentially survive our stomach acid and go on to grow in our gut, causing an infection. ¹ Since the Cornell study in 1998 many groups have tried to contest the results. A study by the USDA Meat and Animal Research Center in Lincoln Nebraska(2000) has confirmed the Cornell research.²

Why this marked difference in the survival of the bacteria? Feeding grain to cattle makes their digestive tracts abnormally acidic. Over time, the E. coli in their systems become acclimated to this acid environment. When we ingest them, a high percentage will survive the acid shock of our digestive juices. By contrast, few E. coli from grass-fed cattle will survive because they have not become acid-resistant. When cattle are fed their natural diet of grass, our natural defenses are still capable of protecting us.

Nonetheless, you should still follow all safe-handling recommendations when you prepare meat from grass-fed animals, especially when cooking ground meat. It takes only a few E. coli bacteria to cause illness.