Lettuce, like other foods, can be contaminated with germs that cause food poisoning. Many dishes are cooked before they’re eaten, killing off most germs. But salads are usually eaten raw, increasing the chance you accidentally eat some hidden bacteria.
There are many opportunities for lettuce to be contaminated with germs that cause food poisoning.
“They are grown in soil that can be easily contaminated by organisms in their farm’s water supply,” says Jenifer R. Lightdale, MD, associate chief of the division of gastroenterology, hepatology, and nutrition at Boston Children’s Hospital. “Contamination can also occur during packaging, as well as during transport to stores and restaurants; while sitting in the refrigerator awaiting food preparation; and even at the moment of being prepared for a meal, especially if the cook has not washed their hands.”
Washing lettuce does not ensure that zero bacteria or germs will be left behind, but it’s a good start.
Reduce Your Chance of Getting Sick
Wash leafy greens that aren’t labeled “ready to eat,” “triple washed,” or “no washing necessary,” according to the Centers for Disease Control and Prevention (CDC). Still, washing doesn’t remove all germs completely, and cooked produce is ultimately the safest choice, according to the CDC.
If you're planning to eat lettuce that is not "ready to eat," make sure to follow these steps from the CDC:
- Wash your hands for 20 seconds with soap and water before and after preparing leafy greens.
- Discard outer leaves and any torn or bruised ones.
- Rinse the leafy greens under running water, and use your hands to gently rub the surfaces of the leaves.
- Don’t soak leafy greens in a sink filled with water — they can get contaminated with germs in the sink.
- Don’t soak leafy greens in a bowl filled with water — contamination from one leaf can spread through the water to other leaves.
- If you don’t have access to safe tap water, rinse with other drinkable water (such as filtered, bottled or distilled water).
- Dry leafy greens with a clean cloth or paper towel.
To safely store your lettuce, the CDC recommends the following:
- Store it separately from raw meats.
- Keep it in the refrigerator.
Illnesses From Eating Bad Lettuce
More than 75.7 percent of leafy–green foodborne illnesses are linked with different lettuces, according to a study. In many cases, lettuce that causes food poisoning is contaminated with:
- Norovirus
- E. coli bacteria
- Salmonella
It takes around two to six hours for food poisoning symptoms to arise after eating contaminated lettuce or other tainted foods, according to MedlinePlus. The time it takes to develop symptoms and the types of symptoms you experience can vary depending on the germ. But food poisoning generally comes with symptoms like:
- Abdominal cramps
- Diarrhea (which may be bloody)
- Fever and chills
- Headache
- Nausea and vomiting
- Weakness (which may be serious)
While food poisoning can be uncomfortable, most cases will resolve within 12 to 48 hours, according to MedlinePlus. But if you experience any of the following, seek medical attention:
- Stool containing blood or pus
- Inability to drink fluids because of vomiting and nausea
- A fever of 101 degrees F or higher, or a fever above 100.4 degrees F along with diarrhea in children
- Dehydration symptoms like thirst or dizziness
- Diarrhea after recent travel to a foreign country
- Diarrhea lasting or worsening after five days or more (two days in children and infants)
- A child vomiting for more than 12 hours
- Food poisoning from mushrooms, seafood, or botulism
