Emerging research is suggesting that in addition to boosting food prices, ethanol production may have another unintended consequence: higher E. coli infection rates in cattle.

In light of growing concern over global warming, ethanol — produced from corn — has been touted as a potentially carbon neutral liquid fuel. Government incentives for ethanol production have provided so much encouragement to the industry that corn prices have skyrocketed.

In 2007, scientists began to notice a sudden increase in contamination of beef products with the E. coli strain O157:H7, which does not harm cows but can be lethal to humans. In that year, the U.S. government recalled beef 21 times due to O157:H7 contamination, with roughly a third of those recalls sparked by reports of human illness due to the bacteria. In contrast, only eight recalls took place in 2006, none of them associated with human illness. In 2008, O157:H7 contamination remained on the rise, with 50 percent more reported cases from January through mid-October than in the same time period of 2007.

Late in 2007, researchers from Kansas State University noticed that cattle fed a diet of distillers grain — the residue left over after the starch has been removed from corn for ethanol production — had significantly higher levels of O157:H7 in their feces than cows fed with regular grain.

The recent spike in ethanol production has resulted in an abundance of distillers grain, driving prices down until it is cheaper than corn. In addition to the cost savings, ranchers favor distillers grain because it is higher in fat and protein than regular corn, leading to fatter cattle for the same amount of feed.