Apiaceae
Petroselinum crispum
Parsley
- Part used
- leafrootseed
- Native range
- The central and eastern Mediterranean
- Morphology
- A biennial to about seventy centimetres with glossy divided leaves — flat or curled by cultivar — and umbels of small yellow-green flowers in the second year.
What is in it
Evidence
Essentially no controlled evidence for medicinal use. The diuretic effect is plausible and unstudied.
Safety
Culinary use is entirely benign. Concentrated parsley seed oil is a different matter: apiol is a uterine stimulant and a hepatotoxin, and deaths from its use as an abortifacient are documented in the twentieth-century literature. High vitamin K content interferes with warfarin. Furanocoumarins cause photosensitivity in handlers.
Interactions: Vitamin K opposes warfarin; Additive photosensitivity; Concentrated oil is contraindicated in pregnancy
Regulatory: Permitted as a food. Apiol-rich preparations are restricted.
How the traditions classify it
Three systems, rating the same plant. Where they disagree, none of them is correcting the others — they are separate frameworks that arrived at their categories independently.
Historical use
Used across Europe as food, garnish and medicine, and associated with death and funerals in Greek practice long before it was a culinary herb. Persistently used as an abortifacient, which is where its serious toxicity record comes from.
Recorded as history and attributed where possible. Long use establishes that a plant was widely used, not that it worked, and not that it was safe.
Worth knowing
Parsley is on the plate at half the restaurants in the world and has a body count, and the two facts belong to different preparations of the same plant.
The garnish is harmless. Concentrated parsley seed oil, rich in apiol, was used through the nineteenth and twentieth centuries as an abortifacient and killed women by liver and kidney failure — the toxicology literature carries the case reports. Italian pharmacies sold apiol preparations commercially for the purpose.
It also carries an interaction almost nobody flags, because nobody thinks of parsley as a drug: it is exceptionally high in vitamin K, and a person on warfarin who starts eating tabbouleh in quantity will move their INR.
Nomenclature verified against GBIF backbone taxonomy.