No one should die from eating a salad. But over the past four months, five people have died and 197 have fallen ill across the country as a result of E. coli infections linked to romaine lettuce, most of it sold chopped and bagged.
According to a June 1 update on the outbreak from the Centers for Disease Control and Prevention, nearly half of these food poisoning patients had to be hospitalized, including 26 people who developed a severe form of kidney failure. All told, the outbreak hit 35 states, with the five deaths occurring in Arkansas, California, Minnesota, and New York.
Eerily, almost the exact same scenario played out in the US a dozen years ago. In 2006, a giant E. coli outbreak linked to bagged fresh spinach sickened more than 200 people and killed three in 26 states. It also involved convenient packaged salad.
As I’ve reported, a 2013 analysis by CDC of food poisoning cases between 1998 and 2008 found that leafy vegetables — salads and the like — caused almost a quarter of all food poisonings. While the vast majority of the salad we eat is safe, leafy vegetables do cause more sickness than any other food product, including dairy and poultry.
Convenience salads are particularly risky. “Historically, the large E. coli outbreaks linked to leafy greens have all been [caused by] prewashed, chopped, bagged salads,” said Bill Marler, a prominent food safety attorney. “[These] mass-produced, washed, bagged, chopped leafy greens that get sent around the country have a lot more risk than people realize.”
It might be time to start rethinking whether packaged lettuces are really worth the risk.
Our salads today look very different from our grandparents’ salads
The salad we consume today looks pretty different from the salad our parents or grandparents ate. Instead of buying heads of lettuce that we wash and chop or rip up ourselves, over the past couple of decades, sales of precut and bagged greens have boomed.
These mixed greens wind up in our fridges or at restaurants already washed and ready to toss in a salad bowl. But during processing, bacteria living among the leafy greens has a moist environment in which to flourish.
“When you bag and chop [salad], bacteria just gets amplified — and when you ship it across the country, the bacteria has a chance to grow in the bag,” Marler explained.
That’s not the only reason salads are a major source of food poisoning. We eat them raw, which means there’s no cooking process to kill off pathogens. Contamination can also happen when lettuce is harvested, or from animals or water in the fields.
In this outbreak, a cluster of cases in Alaska were traced back to whole head lettuce, but the bulk of cases were caused by precut, packaged romaine. The packaging process also makes it more difficult to find the cause of contamination and prevent more people from getting sick. Different lettuces grown at different farms get mixed into bags that are distributed to supermarkets and restaurants all over the country, so food safety officials need to search for the common link among farms and suppliers.
That’s part of the reason the Food and Drug Administration announced last week that we may never know the precise cause of the romaine E. coli contamination. In an incredibly complicated diagram, it showed that a web of dozens of farms, processors, and distributors (all of which remain unnamed) were implicated in the current outbreak. Only the E. coli cases caused by whole head lettuce were traced back to a single farm.
Marler said this could signal that there’s an environmental problem in Yuma. Until the FDA figures out what the problem may be, it may be difficult to trust lettuce that’s grown there.
For now, at least one thing is clear: Greens from the Yuma growing region — the source of the outbreak — are not being sold or served any longer, since the growing season there is over. While that means it’s safe to eat romaine again, we may want to ask: In what form?
I asked Marler what lesson the public and health regulators could learn from these deaths, and he said that we need to understand that our love of convenience has also become a risk. When we eat salads that are prewashed and bagged, we increase our risk of food poisoning.
“Producers of romaine need to rethink the maybe the best way to do this is to send it as whole romaine and let restaurants wash it themselves,” Marler said. Salad eaters may also want to ask whether the convenience of packaged salad is worth the added risk.