Washing produce is never enough, but that’s what a researcher says in a review of causes of foodborne illness. A better suggestion would be rigorous on-farm food safety programs.

In the United States, approximately 179 million cases of acute diarrhea occur each year, and most of those cases are entirely preventable, a researcher from The University of Texas Health Science Center at Houston (UTHealth) concluded in a New England Journal of Medicine review article.

Herbert L. DuPont, M.D., director of the Center for Infectious Diseases at the UTHealth School of Public Health, examined current causes, prevention strategies and treatment for acute diarrhea in healthy adults. He says the main causes of diarrheal infections include norovirus outbreaks and foodborne pathogens, with most coming from contaminated leafy green vegetables.

Produce is the most common source of diarrhea due to foodborne intestinal illness. Most consumers are not aware that 98 percent of spinach and lettuce bought from grocery stores is not inspected and much of it comes from developing countries. One study showed that of the 2 percent that is inspected, 40 percent failed inspection and could be contaminated by diarrhea-producing E. coli or Salmonella.

“Consumers need to give their leafy greens a bath and a shower in order to make sure they are safe to eat,” says DuPont, instructing that leafy greens must be soaked in a bowl of water or the sink and then rinsed thoroughly by running water through a colander before consumption in order to avoid contaminants.