Fenchel (Knolle, roh, bio?)

Fennel is an important crop native to the Mediterranean basin. It is specially adapted to the cultivation in well-drained, loamy soils, with a pH between 5.5 and 7.5, and it can tolerate a range of annual precipitations from 0.3 to 2.6 mm [31]. Due to its rusticity, fennel cultivation does not interest only its domestication center, but regards many other areas characterized by a subtropical and temperate climate, in which this species has been naturalized. Historically, fennel cultivation was accomplished for both food and medicinal purposes. The close bond between man and fennel dates back to the dawn of time. In early Sanskrit literature fennel was named as “madhurika”, yet 2.000 years BC. At the time of ancient Greece, it was considered a symbol of victory since, according to tradition, Marathon battle was fought in a fennel field. Indeed, the Greek name for this plant is “μάραθο” (màratho). Moreover, it was regarded by the Romans as a symbol of success, and its leaves were used to honor the winners in competitions. Mentioned as one of the nine plants in the tenth-century description of the occult'Nine Herbs Charm', fennel holds a significant place in ancient Anglo-Saxon tradition too. During the thirteenth century in England, fennel was esteemed as a royal spice.

Nowadays, the major fennel producers are India, Pakistan, Italy, Russia, USA, Germany, and France [47]. India is the largest fennel producing country, with 90,000 hectares yielding 149,000 tons in 2017–2018.

Fennel is a perennial herb capable of growing up to 2 m. This species has finely divided, branching leaves and a smooth, polished stem that is light green, cylindrical, and upright. The finely divided, filiform (thread-like) segments of fennel leaves can reach a maximum length of 40 cm and a width of 0.5 mm. Inflorescences are represented by large and flat terminal umbels (5–15 cm broad) with 13–20 branches carrying 20–50 yellow golden hermaphrodite flowers on short pedicels. [47]. The fruit is an oblong achene, glabrous, with pronounced ribs and strongly aromatic. As a crop of mild growing conditions, fennel thrives in dry and cold weather, which increases fruit set. On the other hand, high temperatures cause early flowering and relatively low fruit output. The ideal temperature range for its growth is between 15 and 20 °C. Throughout the flowering period, the crop is vulnerable to frost conditions. Fennel can be cultivated as an intercrop or mixed crop because it is long lasting and owns a slow rate of growth at the beginning of the lifecycle. This feature, together with dormancy, was found to be responsible for a poor stability in production yields. To overcome this problem, 8–12 h of soaking are recommended to obtain a uniform germination [31]. Seeds can be placed directly in soil, or seedlings can be let germinate in a nursery and then transplanted. In this latter case, for one hectare, about 2.5 kg of seed are needed,On the contrary, 8–10 kg of seed are needed for direct sowing [74]. Since fennel seeds are tiny, line planting is mainly used. They should be sown no deeper than 1.5–2 cm, with a row spacing of 45–60 × 20–25 cm. Mid-September through the first week of October is the traditional planting season for fennel,for an early season crop, July is recommended for germination in nurseries, and August for transplanting. At 16–18 °C, seeds were observed to take 8–10 days to germinate.

Genetische Studie

DOI: 10.1186/s12870-025-06608-5

Fennel    (Foeniculum vulgare    Mill.)    is    commonly    distinguished    in    two    subspecies    (USDA,    
ARS,     2012):     a)     subsp.     vulgare,     with     var.     azoricum     (Mill.)     Thell,     the     vegetable     Florence     or    
“bulb”    fennel,    and    var.    dulce    (Mill.)    Batt.,    the    sweet    fennel,    which    fruit    is    used    as    a    spice    and    
for    essential    oil    extraction;    a    third    var.    vulgare    should    be    the    wild    ancestor    of    the    cultivated    
types,    but    it    is    commonly    referred    to    as    bitter    fennel,    like,    b)    subsp.    piperitum    (Ucria)    Cout.,    
the     wild     fennel.     “Sweet”     types     are     distinguished     from     “bitter”     by     the     composition     of     their    
anethol-rich    essential    oil.    var.    vulgare    and    subsp.    piperitum    should    be    differentiated    by    their    
growth     habit,     respectively     annual     or     biennial,     and     perennial     (Pignatti,     1982);     however,     in    
Italy     annual     wild     forms     are     seldom     observed     and     transition     forms     between     the     two     may    
occur.    
Wild    fennel    is    likely    a    west    Mediterranean    native,    but    it    is    presently    spontaneous    from    
the    Canary    Islands    to    west    Asia,    and    naturalised    world-wide    (USDA,    ARS,    2012).  

   
In     central     Italy,     wild     fennel     is     characterised     by     short     or     null     summer     and     winter    
22
vegetative    rest,    depending    respectively    on    water    availability    and     temperature;    early    spring    
sprouting;    start    of    flowering    during    the    month    of    June;    start    of    fruit    set    late    June/early    July    
and    fruit    ripening    by    end    of    August    to    mid-October.

Eine ethnobotanische Übersichts- und Feldstudie

DOI: 10.17660/ActaHortic.2017.1153.4

"Wilder Fenchel lässt sich heute mitunter in Italien, vor allem in der Toskana finden. Auch auf der iberischen Halbinsel kommen einige Exemplare an trockeneren und sonnenexponierten Hängen wild vor. Im südlichen Deutschland kann man Fenchel gelegentlich an verlassenen oder ehemaligen Klostergärten ausfindig machen."

"Fenchel stammt ursprünglich aus dem Mittelmeergebiet. Das aromatische Kraut war bereits im Altertum sehr beliebt und hat sich schnell bis in den Vorderen Orient und nach Europa verbreitet. Heute wird der Fenchel vor allem in den südosteuropäischen Ländern, in Indien und natürlich in den nördlichen Mittelmeerländern kultiviert. Sein Vorkommen reicht jedoch bis nach Südamerika und Japan."

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Foeniculum vulgare Mill. is one of the oldest known medicinal and aromatic plants, traditionally valued for its wide range of therapeutic properties. It comprises two main botanical varieties: Foeniculum vulgare var. dulce (sweet fennel) and Foeniculum vulgare var. vulgare (bitter fennel), both widely used in traditional and modern medicine. Historical records even cite an ancient belief attributed to Adam, suggesting that consuming fennel with sugar daily during spring could protect against all diseases, underscoring its long-standing importance in traditional health practices [14]. Fennel is a hardy, perennial, and aromatic herb that can reach up to 2.5 m in height. It has erect, hollow stems, and its leaves are finely dissected and feathery, reaching up to 40 cm in length, with thread-like segments approximately 0.5 mm wide. The plant produces bright yellow flowers arranged in large compound umbels at the tips of the stems [15]. The fruit, often referred to as a seed, is actually a dry schizocarp composed of two mericarps (also called achenes). These are elongated, oval, and ribbed, initially bluish in color and turning brownish-grey upon maturation. The typical size of the fennel fruit is 4–10 mm long and about 3 mm wide, though it may vary depending on growth stage and environmental conditions [16]. Fennel seeds are aromatic and flavorful, widely used as a spice and in herbal remedies. The plant is green to white in color, with bulbous leaf bases that may resemble a swollen stem, especially in cultivated varieties (Figure 1) [17]. It grows wild across much of temperate Europe but is generally regarded as native to the Mediterranean region. Fennel is known for producing a variety of valuable secondary metabolites, used in pharmaceuticals, agrochemicals, fragrances, dyes, biopesticides, and as food additives.

Foeniculum vulgare Mill. (FV), commonly known as fennel, is a medicinal and aromatic plant from the Apiaceae (Umbelliferae) family.

"4.2.1. Flavonoids"

Narratives Review

DOI: 10.3390/ph18111761

Study: weak evidence

Nährstofftabelle

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Die beste Wahl sind feste und unversehrte Knollen mit frischem Blattgrün. Sie sollten vorsichtig behandelt werden, damit sich keine bräunlichen Druckstellen bilden. Im Gemüsefach des Kühlschranks ist Fenchel, eingeschlagen in ein feuchtes Tuch, bis zu einer Woche haltbar.

Und dafür ist jetzt die richtige Zeit, denn die Hauptsaison für heimische Ware ist von Juni bis Oktober.

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"Fennel, also known as Foeniculum vulgare Miller, is an aromatic medical plant and culinary herb that is popular worldwide [6]. Previous studies claim that fennel is effective in reducing gastrointestinal tract dysfunction and dysmenorrhea, relaxing smooth muscles, increasing breastmilk production, and improving age-induced memory deficits [7–9]. Additionally, studies have reported that fennel has anti-inflammatory and antiandrogenic effects [5]. Fennel is also known to have an anxiolytic effect that inhibits anxiety [10]. Several trials that investigated the therapeutic effects of fennel in the management of menopausal symptoms, such as hot flushes, stress, sleep disorders, and vaginal atrophy, also presented positive results [11]. Although there are many claims on its therapeutic effects and no reports of adverse events, the evidence on the clinical effectiveness of fennel in the management of menopausal symptoms remains limited."

Systematische Übersichtsarbeit mit Meta-Analyse randomisierter kontrollierter Studien (RCTs)

DOI: 10.1016/j.ctcp.2021.101360

Study: strong evidence

"For primary dysmenorrhea, cinnamon/fennel/ginger can effectively relieve the intensity of pain, and cinnamon can shorten the duration of pain. However, these findings must be further confirmed in a large number of studies with large sample sizes."

Systematische Übersichtsarbeit und Meta-Analyse randomisierter kontrollierter Studien (RCTs)

DOI: 10.1177/0300060520936179

Study: strong evidence

"The most prevalent flavonoid in polar extract of fennel leaves is quercetin (Agricultural Research Service, 2011). Regarding the potential benefit of fennel consumption on complications associated with diabetes, extract from the edible portion of fennel has been shown to inhibit aldose reductase, and it does so with a high specificity over aldehyde reductase (Saraswat et al., 2008). Thus, fennel may be able to prevent diabetic complications associated with induction of the polyol pathway without inhibiting aldehyde reductase, a detoxification enzyme in the same family. Additionally, consumption of fennel seed extract may be anti-inflammatory. Oral administration of fennel seed extract prevented carrageenan-induced paw edema and arachidonic acid-induced ear edema in mice. Extract of fennel leaves also decreased thermal nociception in mice, suggesting an analgesic effect of fennel (Choi and Hwang, 2004). Fennel bulb but not fennel seed may be antihyperlipidemic. Fennel bulb extract administered total cholesterol, triglycerides, LDL and ApoB in mice after 24 hours. Fennel extract also increased plasma HDL and ApoA1 to levels higher than the hyperlipidemic control. In addition to managing hyperlipidemia, fennel bulb extract prevented lipid accumulation in the coronary artery and decreased hepatic total cholesterol and triglycerides compared to the hyperlipidemic control (Oulmouden et al., 2011). However, when healthy rats were given fennel seed extract orally for 21 days, they experienced no change in blood triglycerides, total cholesterol and LDL. Healthy rats did, however, have greater circulating HDL (Choi and Hwang, 2004)."

Narratives Review

DOI: 10.1080/10408398.2013.805713

Study: weak evidence

"The available scientific research on Foeniculum vulgare has shown that it is an important medicinal plant used in a wide range of ethnomedical treatments, especially for abdominal pains, antiemetic, aperitif, arthritis, cancer, colic in children, conjunctivitis, constipation, depurative, diarrhea, dieresis, emmenagogue, fever, flatulence, gastralgia, gastritis, insomnia, irritable colon, kidney ailments, as a laxative, leucorrhoea, liver pain, mouth ulcer, and stomachache."

"Studies carried out in the past and present indicate that fennel possesses diverse health benefits and are an important constituent of food. Studies have shown that various extracts of fennel possess a range of pharmacological actions, such as antiaging, antiallergic, anticolitic, antihirsutism, anti-inflammatory, antimicrobial and antiviral, antimutagenic, antinociceptive, antipyretic, antispasmodic, antistress, antithrombotic, anxiolytic, apoptotic, cardiovascular, chemomodulatory action, cytoprotection and antitumor, cytotoxicity, diuretic, estrogenic properties, expectorant, galactogenic, gastrointestinal effect, hepatoprotective, human liver cytochrome P450 3A4 inhibitory, hypoglycemic, hypolipidemic, memory-enhancing property, nootropic, and oculohypotensive activity supporting its traditional use. However, the most prominent and the well studied effects are the antimicrobial and
antioxidant effects of essential oil of fennel in different experimental models. The observed health benefits may be credited to the presence of the various phytochemicals like volatile compounds, flavonoids, phenolic compounds, fatty acids, and amino acids."

"The long history of ethnomedicinal application, with no reports of any serious side effects, suggests that F. vulgare could be considered as safe. In most toxicity experiments carried out on F. vulgare, no sign of toxicity was observed."

Narratives Review

DOI: 10.1155/2014/842674

Study: weak evidence

"Anethole is the main fragrance and bioactive compound of anise, fennel, and star anise spices and more than other 20 plant species."

"Evidence indicate that anethole is a natural bioactive compound with multiple beneficial effects in human health such as anti-inflammatory, anticancer, chemopreventive, neuroprotective, spasmolytic, hypotensive, antithrombotic, immunomodulatory, and antidiabetic. It may offer a safe approach in treatment of several chronic diseases, particularly in skin and lung inflammatory disorders, cancer, type 2 diabetes, neurological diseases. The underlying mechanisms for anethole efficacy seem to be the modulation of several signaling pathways, especially, NF-kB, TNF-a, MAPK pathways. Long-term clinical studies are needed to validate its usefulness."

DOI: 10.1007/978-3-319-41342-6_11

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Conclusion: A 60 kDa allergen, highly homologous to Api g 5, was recognized in fennel by patient's IgE. Inhibition experiments showed a high degree of cross-reactivity between this fennel allergen and the homologous mugwort pollen allergen. This allergen might be responsible for the mugwort-celery-spice syndrome.

Klinischer Fallbericht mit immunologischer Untersuchung

Study: weak evidence

"Das HMPC hat Bitterfenchel, Süssen Fenchel und Fenchelöl als traditionelle pflanzliche Arzneimittel eingestuft (siehe „Traditionelle Anwendung“).
ESCOP: Bitterer/Süsser Fenchel und Bitterfenchelöl: bei dyspeptischen Beschwerden wie leichte, krampfartige Magen-Darm-Beschwerden, Blähungen und Flatulenz; Katarrhe der oberen Luftwege; Bitterer Fenchel kann auch zur Linderung von Menstruations­beschwerden eingesetzt werden. Diese Anwendungs­gebiete stützen sich auf Erkenntnisse der langjährigen Anwendung am Menschen.
Kommission E: Bitterer Fenchel und Bitterfenchelöl: Innerlich bei dyspeptischen Beschwerden wie leichte, krampf­artige Magen-Darm-Beschwerden, Völlegefühl, Blähungen; Katarrhe der oberen Luftwege."

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Kapitel 7 "Pharmalogical Activities"

"It is also beneficial for colds and cough. Problem with bronchial tissues can be cured by fennel. The phlegm loosening in lungs can be improved by alpha-pinene that acts as an expectorant. Eye strain and irritation reduction and improvement in eyesight can be obtained by crushed seeds of fennel. Fennel has also been used as a galactagogue. In nursing mothers, seeds boiled in barley water enhance the flow of milk."

"Subtropical and temperate regions are suitable for its cultivation. Ideal growth of fennel herb can be obtained with well-drained, rich, and moist soil. The major fennel growing countries are Pakistan, India, Italy, Russia, the United States, Germany, and France. It is mainly grown in Pakistan and India."

"Fennel is cultivated in temperate areas, but it is native to the Mediterranean region and Southern Europe."

"Fennel is grown in moderate climates in early spring and the winter season. It is a Mediterranean perennial herb. It is mostly found near the sea in dry, stony, calcareous soils. Butterflies and beneficial insects are attracted toward gardens due to this plant. A pH of approximately 5.5e6.5, well-drained, rich soil, and full sun light are required for its proper growth. The main international suppliers of fennel are Egypt, China, and India."

Fennel is an essential component of several industrial applications that range from food to cosmetics to pharmaceutical products. It is used for flavoring, as a spice, and oil of fennel is a key ingredient in liquors, toothpaste, and as flavoring agent in different food products.

DOI: 10.1016/B978-0-08-102659-5.00019-7

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Siehe Tabelle Seite 9

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Untersuchung zum Wasserverbrauch von Lebensmitteln

DOI: 10.5194/hess-15-1577-2011

Fennel (Foeniculum vulgare Mill), a member of the Apiaceae family (Umbelliferaceae), is a hardy and perennial herb, with grooved stems, intermittent leaves, petiole with sheath, usually bisexual flower and yellow umbrella. Although fennel is a typical aromatic plant generally considered native to the Mediterranean shores, it has become widespread in many regions of the world and has long been used as a medicinal and culinary herb.

Collected data show the efficacy of this plant in various in vitro and in vivo pharmacological studies including antibacterial, antifungal, antiviral, antioxidant, anti-inflammatory, antimutagenic, antinociceptive, hepatoprotective, bronchodilatory, and memory enhancing activities. It has also been shown to be effective on infantile colic, dysmenorrhea, polycystic ovarian syndrome and milk production.

Narratives Review

DOI: 10.1080/10408398.2023.2176817

Study: weak evidence

At the field level, insect pollination is fundamental to improve the fruit initiation rate, the fruit weight and the amount of anethole per hectare leading to an estimated 86 % dependence of fennel on insect pollination. Finally, we showed no reproductive limitation with the current state of insect activity. This study adds new evidence of the importance of insects in agroecosystems to sustain food production.

Experimentelle Feldstudie

DOI: 10.1016/j.agee.2022.108047

Pesticides are an important potential cause of biodiversity and pollinator decline.

At the regional scale, lower bumblebee and butterfly species richness was found in the more intensively farmed basin with higher pesticide loads. Our results suggest that wild bees are an insect pollinator group at particular risk from pesticide use.

Feldbasierte, beobachtende Studie mit experimentellem Design

DOI: 10.1016/j.baae.2009.11.007

F. vulgare is believed to
have potential therapeutic effects on various ailments,
such as cancer, arthritis, mouth ulcers, hypertension, high
cholesterol, liver discomfort, irritable bowel syndrome,
and kidney issues (Al-Amoudi, 2017).

"Table 1: Chemical compositions of essential oil identified from
FSEO using GC-MS"

"Table 3: Total phenolic, flavonoids and tannins and antioxidant
activity of FSEO"

In-vitro‑Laborstudie

DOI: 10.3844/ojbsci.2025.617.626

Study: weak evidence

The brown algae showed to contain high amount of iron, and the effect of feeding
experimental animals on casein control diet and casein diet containing different percentage of
Foeniculum vulgare is shown in Table 8. It was found that the blood hemoglobin levels of the
casein control group was 12.8 g/dl, and significantly lower than all tested diets. The blood
hemoglobin level was increased as Foeniculum vulgare percent in casein diet increased. The
mean values recorded for 5, 10, 15, and 20% Foeniculum vulgare in casein diets were 12.97,
13.31, 13.67, 13.89 g/dl, respectively. The highest hemoglobin level (15.3 g/dl) was found among Foeniculum vulgare group, and significantly higher than all tested groups. The results
agreement with (Asbaghi et al ., 2021), they found that fennel supports healthy blood
hemoglobin levels due to its iron and histidine content, helping in hemoglobin production and preventing iron-deficiency anemia. The vitamin C in fennel also aids in iron absorption, while folate supports red blood cell formation. Additionally, studies have shown fennel can increase red blood cell counts and overall hemoglobin levels in various study groups.

Experimentelle Tierstudie (in vivo)

Study: weak evidence