Parsley

Scientific Name(s): Petroselinum crispum (Mill.) Nyman ex A. W. Hill.
Common Name(s): Garden parsley, Parsley, Rock parsley

Medically reviewed by Drugs.com. Last updated on Oct 7, 2021.

Clinical Overview

Use

Parsley, in addition to being a source of certain vitamins and minerals, has been used traditionally for widespread uses. Limited laboratory studies suggest parsley has antiplatelet activity as well as antimicrobial, immunosuppressive activity, and cytotoxic and spasmolytic effects. Clinical trials are, however, lacking to support any therapeutic recommendations.

Dosing

Parsley leaf has been used at daily doses of 6 g; however, no clinical studies have been found that support this dose. The essential oil should not be used because of toxicity.

Contraindications

Contraindications have not yet been identified.

Pregnancy/Lactation

Generally recognized as safe when used as food (GRAS). Safety and efficacy for dosages above those in foods are unproven and should be avoided. Emmenagogue and abortifacient effects may occur with higher doses.

Interactions

Although case reports are lacking, a theoretical interaction may exist with antiplatelet medicines. Parsley juice may alter the activity of drugs affected by cytochrome P450.

Adverse Reactions

GRAS when used as food. Adverse effects from the ingestion of parsley oil include headache, giddiness, loss of balance, convulsions, and renal damage.

Toxicology

While no major toxicities have been reported with the use of parsley, pregnant women should not take parsley because of possible uterotonic effects.

Scientific Family

• Apiaceae (carrot)

Botany

Parsley is an annual herb indigenous to the Mediterranean region, but now cultivated worldwide with numerous varieties available. It has erect stems and non-hairy bright green leaves. Parsley produces an umbel of tiny flowers and characteristic ribbed fruit ("seeds"). Parsley seed oil and herb oil are obtained from the above-ground plant parts by steam distillation, while the dried leaf flakes are sold commercially as a culinary herb.1, 2, 3

Caution must be used when gathering wild parsley because of the general similarity of its leaves and flowers to those of 3 common poisonous plants. The first, Aethusa cynapium (dog poison, fool's parsley, small hemlock) can be distinguished from parsley by the shiny yellow-green underside of the leaves, which are dull in parsley, and the white flowers, which are yellowish in parsley. Similarly, collectors should be aware of Conium maculatum (poison hemlock, water hemlock, poison parsley) and Cicuta maculata (water hemlock). Poison hemlock is a much larger plant than common parsley. Poisonings have occurred when the leaves of Conium were mistaken for parsley and the seeds for anise. Symptoms of Conium and Cicuta poisoning include vomiting, diarrhea, weakness, paralysis, weak pulse, dilated pupils, convulsions, and death.

History

Parsley leaves and roots are popular as condiments and garnish worldwide. In Lebanon, parsley is a major ingredient in the national dish called tabbouleh. An average adult may consume as much as 50 g of parsley per meal.4

Parsley seed was used traditionally as a carminative to decrease flatulence and colic pain. The root was used as a diuretic and the juice to treat kidney ailments. Parsley oil has also been used to regulate menstrual flow in the treatment of amenorrhea and dysmenorrhea, and is purported to be an abortifacient. Bruised leaves have been used to treat tumors, insect bites, lice, skin parasites, and contus...