Lettuce

Studies in people

• Benefit

  Blood iron and cholesterol⁴

  Eating lettuce grown with a seaweed spray raised blood iron and lowered cholesterol in healthy adults.

Found in some samples or products

These come from where it was grown, how it was processed or cooked, or what it was made into. They are not about the ingredient itself, so the signal does not count them.

• Food poisoning from salad²

  Listeria can be found in fresh vegetables, including precut prepackaged lettuce, but no recent outbreaks are linked to it.

• Cancer risk from vegetables³

  In people eating lettuce and cabbage from one Iranian region, the authors found an unacceptable cancer risk from heavy metals.

• Washing reduces residues⁵

  Half the lettuce from a La Paz market had pesticides, and washing cut levels but some stayed above limits.

The signal at the top counts the findings in people and in animal and lab studies. A concern in studies of people outranks animal and lab studies, and “No concerns” needs at least one finding in people. When most findings in people point one way, the page leans that way (“Mostly”), and every finding is still shown. Findings whose study type is not stated are shown but not counted. This page is a reference, not medical advice. It describes what regulators and published research say. Talk to a doctor or dietitian about your own diet.