Eating grass-fed beef lowers your risk of E. coli infection

When you eat grass-fed meat, you may have a lower risk of becoming infected with dangeroue E. coli bacteria.

Why is this? First of all, work conducted at Cornell University has determined that grass-fed animals have far fewer E. coli than grain-fed animals.

What's more, the small amount they do have is much less likely to survive the natural acidity of our digestive tract—our first line of defense against infectious diseases.

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.

Russell, J. B., F. Diez-Gonzalez, and G. N. Jarvis. "Potential Effect of Cattle Diets on the Transmission of Pathogenic Escherichia Coli to Humans" Microbes Infect 2, no. 1 (2000): 45-53. (Chart data extracted from this document.)