Leafy vegetables now a growing health threat

CHICAGO — A growing threat for food-borne illnesses comes attractively packaged, is stunningly convenient and is increasingly popular with shoppers looking for healthy meals: ready-to-eat leafy greens that make putting together a green salad as easy as opening a bag.

Though beef and poultry are a more frequent source of food-related outbreaks than produce, the number of outbreaks tied to lettuce, spinach and other leafy greens, whether fresh-cut or whole, has been rising over the past two decades, according to the nonprofit Center for Science in the Public Interest.

On Tuesday, researchers with the group called leafy greens the riskiest food regulated by the Food and Drug Administration, with 363 outbreaks linked to those foods from 1990 to 2006. (Meat is regulated by the U.S. Department of Agriculture.)

The largest and most severe outbreak came in September 2006, when bagged baby spinach tainted by E. coli bacteria sickened some 200 people and left three dead in 26 states. Last month, salmonella detected in testing prompted the recall of 1,715 cartons of bunched spinach sent to a dozen states.

"For a long time, produce was considered a safe item," said Jim Prevor, editor in chief of the food- safety blog perishablepundit.com. "But that's not really the case anymore."

Hoping to ensure greater safety and cut the number of food-related outbreaks, the Agriculture Department has launched hearings around the country aimed at developing national production and handling rules for vegetables.

Although consumers can reduce their risk, such as by washing greens, that isn't always enough. Experts say preventing outbreaks requires action by farmers and producers to avoid bacterial contamination at the source or during processing.

Greens are vulnerable for several reasons, including that they are grown so close to the ground — unlike, say, fruit from trees — and can be tainted by water runoff, a persistent source of contamination when it carries animal waste.

What makes fresh-cut greens more susceptible is also what makes them convenient: the cutting and bagging that eliminates much of the work of salad preparation. That processing allows pathogens to get into the leaves, where they can flourish. The machinery used and the mixing of greens from various farms contribute to those dangers, not unlike the risks associated with processing ground beef.

Even greens put through a chlorine wash can be contaminated.

"Consumers shouldn't change their diets to avoid these foods," said Sarah Klein, a staff attorney at the Center for Science in the Public Interest. "The bottom line is that consumers need help from the food industry and the FDA if they want to eat nutritious and safe foods — which is why these products need to be safe when they arrive in consumer and restaurant kitchens."

The center's researchers found that six outbreaks of disease and 598 illnesses were linked to greens in 1990. In 2006, the most recent data available, there were 49 such outbreaks and 1,279 illnesses.

The 2006 E. coli outbreak prompted growers and handlers of leafy greens in California, where most of the nation's lettuce and spinach is grown, to adopt a voluntary plan calling for tougher safety rules and regular inspections. Arizona, second to California in greens production, followed.

Now, a similar safety agreement may be crafted for green handlers nationwide.