Francisco Diez-Gonzalez, director of the Center for Food Safety in the College of Agricultural and Environmental Sciences, spoke with Food & Wine about the potential risks of not washing lettuce.
“Based on epidemiological data of a number of outbreaks, enterohemorrhagic E. coli and Cyclospora are the greatest concerns,” Diez-Gonzalez said.
According to the Food and Drug Administration, these bacteria put people at risk for developing uncomfortable symptoms like diarrhea, fever and stomach cramps. These bacteria can be extremely harmful and even deadly for high-risk categories such as young children, older adults and immunocompromised individuals.
“Listeria is also a potential risk,” Diez-Gonzalez said. Like E. coli and Cyclospora, listeria can cause diarrhea, fever and flu-like symptoms.
Diez-Gonzalez noted that lettuce can be contaminated during any step of the growing process and the bacteria could be lingering beneath the surface of your greens.
“Washing may not eliminate all pathogen contamination,” said Diez-Conzalez.
Through washing, cooks may get a 90% reduction in pathogens, according to experts.
Pre-washed greens have a higher risk of contamination.
“Some outbreaks have been associated with bagged salads, which have been washed by the manufacturer most of the time,” Diez-Gonzalez said.
It is unlikely that washing pre-washed greens will be helpful if they have been contaminated during the growing process through soil or irrigation water. However, giving them a rinse can help minimize the risk, said Diez-Gonzalez.