Why Does Lettuce Make Us Sick So Often?

Contaminated lettuce has been astatine nan bosom of this year’s largest U.S. outbreak of cyclosporiasis, an unwellness caused by nan parasite cyclospora that leads to explosive diarrhea, vomiting and dehydration that lands group successful nan hospital.

But this isn’t nan first clip lettuce has been implicated successful outbreaks of nan disease. In 2018, an outbreak linked to salads from McDonald’s sickened much than 500 Americans crossed 16 states, national information shows. Two years later, an outbreak tied to Fresh Express bagged crockery affected much than 700 group and a 2022 outbreak was traced to Caesar salad kits.

And it’s not conscionable cyclosporiasis we request to interest astir pinch lettuce, which has besides been tied to E. coli and Salmonella outbreaks.

So, why is lettuce specified a communal culprit of foodborne illness? Well, location are a mates of reasons. For one, we eat a batch of it. The mean American consumes an mean of 25 pounds of lettuce annually.

Secondly, lettuce is difficult to wash, which tin time off you susceptible to immoderate hitchhiking germs aliases parasite. “If you don't lavation these products well, you're going to extremity up ingesting immoderate is connected nan lettuce,” Amira Roess, an epidemiologist astatine George Mason University, told WIRED.

Bacteria and parasites tin hide heavy successful nan crevices betwixt lettuce leaves, and it doesn’t thief that lettuce grows adjacent to nan soil, either.

The person nutrient is to soil, nan much apt it is to travel into interaction pinch contaminated h2o that tin dispersed cyclospora widely.

Contaminated h2o is nan apt root of astir large outbreaks, including this one, experts told The New York Times past week.

“You’d person to person a batch of nutrient being irrigated pinch a batch of h2o that was contaminated by a batch of cyclospora to spot this number of cases,” Keith Schneider, a professor of nutrient information astatine nan University of Florida, said.

And because of lettuce leaves’ reliable yet vulnerable exterior, nan versatile nutrient tin beryllium harder to cleanable than smooth-skinned products.

Broken leaves are besides a problem, Barbara Kowalcyk, head of nan Institute of Food Safety and Nutrition Security astatine George Washington University, told TIME.

She explained "that's really nan germs gets inside.”

Relying connected pre-washed lettuce is not needfully safe, either. Pre-washing whitethorn not region microbes clinging to nan leaves, including cyclospora, nan University of Connecticut Extension said.

Lastly, we eat lettuce earthy connected sandwiches and successful salads. That’s a large portion of nan problem.

Heating nutrient perchance contaminated pinch cyclospora to a somesthesia of 158 degrees Fahrenheit is nan only point that kills nan parasite.

Cooking tin besides beryllium effective against immoderate strains of Salmonella and E. coli, if done right.

Parsley and cilantro are reportedly besides tied to cyclospora cases successful North Carolina, according to nan New York Post.

Herbs person a batch of nan aforesaid problems lettuce does. We eat them raw, they turn adjacent to nan crushed and they’re often reliable to clean.

Consumption of these herbs is rising, too, nan U.S. Food and Drug Administration points out.

“Because these herbs whitethorn commonly beryllium consumed without washing aliases a ‘kill-step,’ specified arsenic cooking, location whitethorn beryllium an accrued consequence of quality unwellness if microbial hazards are present,” nan agency warns.

But experts opportunity eating thing that could beryllium affected is apt not worthy nan risk, whether that’s lettuce aliases different nutrient tied to foodborne illness.

“People often laughter erstwhile they perceive nan building ‘explosive diarrhea,’ but for nan individuals experiencing it, there’s thing humorous astir it,” Darin Detwiler, a professor emeritus astatine Northeastern University, told Serious Eats. “Behind each reported lawsuit is simply a personification whose life has been unexpectedly interrupted simply because they ate nutrient they believed was safe.”