Fennel Seeds: What Are Their Benefits?

Fennel seeds Fennel are produced by common fennel, known by its Latin name Foeniculum vulgare, a plant belonging to the Apiaceae family. Native to the Mediterranean basin, it has been known since at least ancient Greece. It appears that fennel seeds spread as far as Brittany during the Roman invasions, carried there by soldiers. There are two varieties: wild bitter fennel, Foeniculum vulgare var. Vulgare, and cultivated sweet fennel Foeniculum vulgare var. dulcis. Foenuculum means “little hay,” vulgare, “common,” and dulcis, “sweet.” Both varieties of fennel (sweet and bitter) are used for their leaves, stems, and seeds. Their seeds contain proteins, mucilage, coumarins, flavonoids, phenol methyl ethers (such as trans-anethol), a ketone (fenchone), anise alcohol, anise aldehyde, and monoterpenes such as limonene and alpha-pinene. The seeds contain 0.8 to 6% essential oil.

Focus on Wild Fennel

Wild fennel does not produce a bulb like its cultivated cousin, so it is primarily its seeds that are consumed for their aromatic properties in cooking and for their therapeutic benefits. However, wild fennel cannot meet global demand, so it is preferable to obtain fennel seeds from the cultivated variety.

Digestive properties: Fennel seeds are known for their carminative properties, meaning they help reduce gas and bloating. They can also stimulate bile production, thereby promoting better digestion. As antispasmodics, they improve digestion from the stomach to the intestines. In fact, fennel seeds regulate the fermentation process of food, thereby reducing discomfort and unpleasant symptoms. Infant colic can be alleviated if the breastfeeding mother consumes them. The seeds also have an antiseptic effect on the gut flora, which can help fight infections or parasites.

Fresh breath: When chewed after meals, fennel seeds not only aid digestion but also freshen breath.

Weight loss support: Since fennel seeds improve digestion and help stabilize blood sugar levels, they can contribute to weight loss when combined with a proper, balanced diet. What’s more, they have diuretic properties, meaning they increase urine production and elimination, which helps promote drainage of the kidneys and urinary tract, thereby preventing edema and urinary disorders. Additionally, the diuretic action helps eliminate toxins and metabolic waste. 

Regulation of the menstrual cycle: Fennel is traditionally recognized for its effect on the menstrual cycle due to its high content of anethole, a compound with estrogen-like properties (capable of mimicking the action of estrogen in the body). It can thus help regulate menstrual cycles and alleviate certain premenopausal symptoms, such as hot flashes.

A galactogenic effect: Fennel is also known for its galactogenic effect, meaning it may promote the production and secretion of breast milk. However, its use by breastfeeding women is subject to warnings, as anethole may, if consumed in excess, cause neurotoxic effects in infants. It is therefore recommended to use it with caution and under medical supervision while breastfeeding.

Mucolytic and expectorant properties: thanks to their high content of anethole and fenchone, fennel seeds possess mucolytic and expectorant properties, promoting the elimination of mucus in cases of respiratory tract inflammation. They are sometimes used to relieve productive coughs and improve respiratory comfort. They are found in particular in certain cough syrups designed to alleviate the symptoms of mild respiratory conditions, such as the common cold or mild bronchitis.

Support for eye comfort: Fennel seeds can be used as a decoction or applied as soaked compresses to tired or irritated eyes. Thanks to their anti-inflammatory and antiseptic properties, they help soothe eye strain and can be used as a complementary treatment for mild conjunctivitis.

Cosmetic properties: Rich in antioxidants, particularly anethole, fennel seeds help protect skin cells from the effects of free radicals, which are responsible for skin aging. Their purifying, stimulating, and soothing action is enhanced by their anti-inflammatory and antiseptic properties, making them a valuable ingredient in skincare.

In short, fennel seeds contribute to:

• Digestive support: aids digestion, reduces bloating and intestinal spasms

• Menstrual cycle regulation: estrogen-like effect that helps balance cycles and alleviate premenopausal symptoms

• Breastfeeding support (use with caution): traditionally used to stimulate lactation, but should be used in moderation

• Expectorant properties: Facilitates the elimination of mucus in cases of productive cough or respiratory tract irritation

• Eye soothing: used in compresses to relieve eye strain and mild irritation

• Cosmetic properties: rich in antioxidants, they protect, purify, and stimulate the skin.

1. As an infusion: steep 1.5 to 2.5 g of seeds in 150 ml of hot water, up to three cups a day.

2. In cooking: Fennel seeds are easy to incorporate into dishes, adding a subtle aniseed flavor. They can be used as a garnish, in salads, soups, or desserts. To enjoy their benefits without overdoing it, limit yourself to 1 teaspoon per dish.

3. As dietary supplements: Available in capsules, standardized extracts, or essential oil, these concentrated forms require following the manufacturer’s instructions and precautions for use, particularly for essential oil, which is potent and must be used with caution.

4. In cosmetics: an infusion of fennel seeds can be applied as a skin toner to purify and soothe the skin. Fennel extracts are also found in creams, body lotions, and serums. When ground into a powder, the seeds can also be incorporated into homemade toothpaste with refreshing and purifying properties.

Consumption of fennel seeds should be moderate, particularly among pregnant and breastfeeding women, due to their content of anethole, a substance with estrogen-like effects. 

To fully enjoy the benefits of fennel seeds, use them in tea or in cooking, in their natural and balanced form. If you wish to consume them as dietary supplements or essential oil, be sure to strictly follow the recommended dosages and consult a healthcare professional if in doubt.

Catherine is passionate about plants and their properties. She studied natural cosmetics at the École Lyonnaise des Plantes Médicinales in the early 2000s. Driven by curiosity, she has continued to explore the richness and potential of plants. This led her to train in aromatherapy at the École Française d’Aromathérapie Intégrative. She discovered an almost unexplored world in olfactotherapy, and valuable tools for getting to know herself better and practising what she calls inner ecology.