Natural Products

Fennel

Scientific names: Foeniculum vulgare Mill. syn., Foeniculum officinale All., and Anethum foeniculum Family: Apiaceae (carrots)

Common names: Common, sweet, or bitter fennel, carosella, Florence fennel, finocchio, garden fennel, large fennel, wild fennel

Efficacy-safety rating:

Ò...Little or no evidence of efficacy.

Safety rating:

●...Little exposure or very minor concerns.

What is Fennel?

Fennel is an herb native to southern Europe and Asia Minor. It also is cultivated in the US, Great Britain, and temperate areas of Eurasia. All parts of the plant are aromatic. When cultivated, fennel stalks have grown to a height of 3 feet. The seeds have a taste resembling that of anise. F. dulce (“carosella”) is grown for its stalks, while F. vulgare (“finocchio”) is grown for its bulbous stalk bases. A number of subspecies have been identified and their names add to the potential confusion about the nomenclature of these plants.

What is Fennel used for?

Traditional/Ethnobotanical uses

According to Greek legend, man received knowledge from Mount Olympus as a fiery coal enclosed in a stalk of fennel. The herb was known to the ancient Chinese, Indian, Egyptian, and Greek civilizations; the Roman scholar Pliny recommended it for improving eyesight. The name foeniculum is from the Latin word for “fragrant hay.” Fennel was in great demand during the Middle Ages. Wealthy people added the seed to fish and vegetable dishes, while the poor reserved it as an appetite suppressant to be eaten on fasting days. The plant was introduced to North America by Spanish priests and the English brought it to their early settlements in Virginia. All parts of the plant have been used for flavorings, and the stalks have been eaten as a vegetable. The seeds serve as a traditional carminative. Fennel has been used to flavor candies, liqueurs, medicines, and food, and it is especially favored for pastries, sweet pickles, and fish. The oil can be used to protect stored fruits and vegetables against growth of toxic fungi. Beekeepers have grown it as a honey plant. Health claims have included its use as a purported antidote to poisonous herbs, mushrooms, and snakebites. It also has been used for the treatment of gastroenteritis, indigestion, to stimulate lactation and as an expectorant and an emmenagogue (to stimulate menstrual flow). Tea made from crushed fennel seeds has been used as an eyewash. Powdered fennel is said to drive fleas away from kennels and stables.

General uses

As an herbal medicine, fennel is reputed to stimulate lactation, promote menstruation, facilitate birth, ease male “menopause”, and increase libido. Research reveals no clinical data supporting the use of fennel as a stimulant for lactation or menstruation, although animal studies support a possible estrogenic effect.

What is the dosage of Fennel?

Fennel seed and fennel seed oil have been used as stimulant and carminative agents in doses of 5 to 7 g and 0.1 to 0.6 mL, respectively.

Is Fennel safe?

Contraindications

Contraindications have not yet been identified.

Pregnancy/nursing

Documented adverse reactions and emmenagogue (stimulating menstrual flow) effects. Avoid use.

Interactions

None well documented.

Side Effects

Fennel may cause photodermatitis, contact dermatitis, and cross reactions. The oil may induce reactions such as hallucinations and seizures. Poison hemlock may be mistaken for fennel.

Toxicities

Fennel oil was found to be genotoxic in the Bacillus subtilis DNA-repair test. Estragole, present in the volatile oil, has been shown to cause tumors in animals.

References

Fennel. Review of Natural Products. Facts & Comparisons 4.0. http://online.factsandcomparisons.com/MonoDisp.aspx?monoID=fandc-rnp-5127&quick=Fennel. August 2007. Accessed October 16, 2007.