‘One of the riskiest items in the grocery store,’ according to food expert

Your good health habit could actually get you seriously sick — and you wouldn’t know until it’s too late.

While experts unanimously agree that we should all be eating more fresh, whole foods, a food policy professor has a warning: Danger lurks in your grocery store’s produce aisle.

Not all fruits and veggies are created equal, and a popular choice for easy meals that save you time could come with the price of contamination.

“Prewashed bagged greens remain one of the riskiest items in the grocery store,” Darin Detwiler, a professor of food policy at Northeastern University and author of “Food Safety: Past, Present, and Predictions,” told Huffington Post.

“When you look at past outbreaks, bagged salads have been a leading cause of foodborne illness, with some outbreaks resulting in hospitalizations, kidney failure, and even death.”

Those pre-mixed bagged salads can harbor pathogens like listeria, salmonella, and E. coli and pose a higher risk for contamination through the supply chain and are among the worst offenders for food safety.

According to the Centers for Disease Control and Prevention, food poisoning symptoms from bacteria like listeria or E. coli — which cause infections in the gastrointestinal tract — include nausea, vomiting, fever, abdominal pain, and diarrhea.

According to a 2024 report in the Journal of Foodborne Illness, leafy greens are credited with “up to 9.2% of known pathogen-caused foodborne illnesses” in the U.S, resulting in over 2.3 million cases of illness each year.

What makes these speedy veggies particularly dicey is that heat is required to kill pathogens — and salads are typically eaten raw, making it difficult to reduce the risk of foodborne illness once they reach consumers.

Contamination of these mean greens can occur at different stages of production.

Produce can be contaminated during lettuce collection by pathogens in the water, soil, or air, or by wild or domesticated animals. Leafy greens are sometimes grown near large-scale cattle operations, a proximity that increases the likelihood that E. coli, salmonella, and listeria could be introduced through contaminated irrigation water.

Detwiler cites manure lagoons, large pits where livestock waste is stored, as a common source of food contamination.

“Runoff from manure lagoons can seep into irrigation canals and contaminate fields with deadly bacteria like E. coli,” he said.

Post-harvest, lettuce can be compromised through human handling, contaminated equipment, or water used to remove soil.

Typically, lettuces from various farms are processed in a centralized area, meaning your bag of greens is more of a menagerie of fetid potential than a single source.

“Greens from different farms are mixed, washed, and packaged together, so one contaminated leaf can impact thousands of bags across multiple states,” said Detwiler.

The large vats that facilitate this washing are also an effective way to spread bacteria.

To prevent the proliferation of pathogens, greens must be kept cold; if lettuce is not consistently kept at these cooler temperatures throughout the supply chain, bacteria can easily breed and reach store shelves.

But refrigeration just slows bacteria growth, it doesn’t kill them.

Washing greens is also ineffective at removing pathogens. In fact, doing so also double down on the danger, as doing so can introduce contamination from the sink, utensils, equipment, and the compromised hands of the washer themselves.

What’s a leaf-eater to do? Consume carefully.

Consider ditching bagged greens entirely and opting for whole heads of lettuce or loose bunches. He recommends whole heads of lettuce or spinach, which have less surface area for contamination. Just rinse the leaves under cold running water to remove dirt and surface-level bacteria.

If you’re bag or bust, Detwiler advises buyers to skip greens that appear wilted, slimy, or discolored and avoid those in packages that look wet, as these signs could indicate improper storage.

Further, avoid subjecting your greens to drastic temperature changes. Keeping them in a hot environment or even on the counter at room temperature can create an environment for bacteria to grow and spoilage to take hold.

Finally, stay up to date on recalls and double-checking expiration dates, only buying greens that you plan to use within 2 days.