Leek

Studies in people

• No harm found

  Bowel cancer risk⁴

  Eating leek was not linked to colon or rectum cancer in this study of older adults.

Study type not stated

• Benefit

  Health effects of a vegetable⁵

  Leeks may fight cancer, inflammation and germs, but scientists do not yet know how these effects work.

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 outbreak³

  In this outbreak, people who ate leeks in cheese sauce at a restaurant were far more likely to get sick.

Single cases of misuse or overdose

One person or one incident, such as an accidental overdose or a mistake in a kitchen or factory. They are real, but a single case does not show what happens at normal amounts, so the signal does not count them.

• Allergic reaction to food²

  A woman had a severe allergic reaction to leek, but only when she exercised after eating it.

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.