“In the black seed is the medicine [to cure] every disease except death”– Arab Proverb
Black Cumin (N. sativa) flower
Image Source: Terroir Seeds
Nigella sativa L. (Ranunculaceae)
Black Cumin, Black Seed, Fennel Flower, Roman Coriander, Small Fennel, Black Caraway, Fitch, Nutmeg Flower, Seed of Blessing, Cumin Noir, Nigella, Kaladuru, Hognut, Kippernut, Habba soda, Kalojeere, Kalonji, Assamese, Hak Jung Chou, Shonaiz, Kalajira, Habah al-brekah, Nigelle de Crète, Toute épice, Schwarzkümmel, Cominho-negro, Ajenuz, Arañuel, Baraka, Charnuska, Poivrette, Upakuncika, Svartkummin and Černuška Posevnaja(GRIN, 2020), (eMedicine, 2019).
Claimed to be native to Southern Europe, North Africa, and Southwest Asia, the true origin of Nigella sativa (N. sativa) is thought to be North-West Africa (Hepper, 2009). Currently, N. sativa is found in many places around the world and is traded across global markets. The majority of the current black cumin and its products are produced in India, Bangladesh, Turkey, Middle East, China, United States, and Germany (Albert-Matesz, 2003; Ahuja and Singh, 2019).
Food grade and cosmetic grade are the two forms of N. sativa commonly available in the market. N. sativa plants can grow in hardiness zones 3-10, which range in temperatures from -40 °F to 40 °F, growing well in cool, humid, and dry areas alike. Black cumin can tolerate environmental stressors including frost, snow and pests (Go Botany, 2020). Seeds are harvested directly from the wild for culinary purposes and the flowers are favoured as ornamentals. Due to its growing popularity in the cosmetic, nutraceutical and food markets, N. sativa is being grown in places other than its native origin, including China, Chile and Europe (Datta et al., 2012).
Figure 1: Current locations of N. sativa cultivation distribution.
Credit: Heiss et al., 2013.
N. sativa is one of the oldest dicotyledonous herbs that have been used for centuries in various cultures. This annual flowering plant reaches 30-60 cm at maximum height, excluding the tap root (Attokaran, 2017). Trichomes are present on the woody stem and divided leaves (Go Botany, 2020). N. sativa has 4-10 branches per plant that have alternating compound leaves that appear long and slender (Ahmad et al., 2013). The plant flowers in early June or July, producing solitary blossoms that are long lasting (Datta et al., 2012). Flowers have 5-10 petals and a white to pale-bluish hue, while terminal flowers are greenish or dull mauve (Hepper, 2009). The black cumin flowers can grow up to 13 or more stamens. N. sativa is a hermaphrodite, containing both male and female organs and fertilized via pollination by bees. Numerous black triangular pyramid shaped seeds develop in horned capsules (Ahmad et al. 2013). Black cumin seeds can vary in colour from black, yellowish brown to dark red or bicolour and can be up to 1.2 mm in length (Datta et al., 2012).
Figure 2: Morphological appearance of Nigella sativa plant, seeds and flowers
Credit: Attokaran, 2017
Cultivation of N. sativa began more than 3,000 years ago by the Assyrians. Currently, the largest place of cultivation occurs in Turkey, India, Syria, Lebanon, Israel and Southern Europe (Fig. 1). Turkey cultivates 8,122,010 hectares and India cultivates 6,234,600 hectares of N. sativa annually (Datta et al., 2012).
N. sativa is grown once a year as a Rabi crop, which is planted in April and harvested in October. Varying climates lead to different planting schedules and seeds can be cultivated in most arable lands, including plains, hills and waysides. N. sativa grows best in climate conditions that are warm and humid which stimulate plant growth. Cool and humid climate favours flowering and seed development (Datta et al., 2012). Soils should range from sandy to sandy loam, allowing for good drainage, with a pH of 7-7.5 and with many soil microbes. New crop can be planted from a previous year’s seed stock or rootstock (bulb) if there is enough soil moisture. N. sativa requires irrigation during seed formation and flowering to increase the seed oil content (Attokaran, 2017). In addition, black cumin plants require a significant amount of manual labour during the planting and growth season and at harvest. During cultivation, plants need to be weeded 3-5 times a month, due to its poor weed competition abilities (Datta et al., 2012). Harvesting occurs as the capsules start to turn yellow, just before the shedding of the seed capsules (Ghouzhdi, 2010). This ensures the seeds have the highest amount of aromatic oil content which is valued highly in the market as well as improved seed viability (Ghouzhdi, 2010). N. sativa requires hand harvesting to avoid shattering the seed capsule. Once harvested, the capsules are dried under the sun and then threshed with a stick to separate the seeds from the capsule. Once threshed, no additional post-harvest handling is required due to the seeds’ unique self-preserving and natural deterrent properties. Seeds can be stored for a year, or until the next planting season (Datta et al., 2012).
Figure 3: Black cumin seeds (left) and capsules before harvest (right) valued for its fennel smell and nutmeg taste.
Image Source: Shutterstock.com
Despite the growing uses of N. sativa in cosmetics, food and the nutritional supplement market, it is classified as not extinct (GMI, 2019a). Based on its ability to grow in various climates and its commercial cultivation in areas around the world, its habitat is not at risk.
Throughout history, black cumin has played a critical role in the progress of medicinal plant use. Traditionally, N. sativa seeds have had many uses due to their anti-fungal, anti-bacterial, anti-inflammatory and anti-viral properties (Padhye et al., 2008). Applications of the seed include detoxification, purging parasites, treatment of abscess, ulcers or tumors, headaches, asthma, local anaesthetic and as a remedy for tooth aches. Herbal medicine utilized N. sativa as the treatment for various sores, bites and skin irritation (Botnick et al., 2012). The seed are ingested as digestive aid after large celebratory feasts and also used as a beauty product as popularized by Egyptian Queen Nefertiti (Albert-Matesz, 2003). More commonly, black cumin is used in food products to flavour breads, curries and confectionaries in South Asian countries (Botnick et al., 2012).
Cultural and Spiritual Significance
The use of N. sativa has been recorded in multiple religious books for a variety of medicinal and spiritual purposes (Schmall, 2007). In traditional Islamic and Ayurveda medicine, black cumin is referred to as ‘Panacea (cure all). In Arabic, the seeds are called ‘Habbah Sawda’ and ‘Habbat el Baraka’, which means ‘seeds of blessing’ (Petruzzello, 2018). N. sativa is referred to as one of the oldest and strongest ancient remedies in the Prophetic Medicine and was used in traditional healing rituals since the 1400’s. Accompanying N. sativa during ritualistic ceremonies were honey, herbs and healing prayers from the Qur’an (Schmall, 2007). This process was thought to increase the deliverance and healing abilities of the seeds. The prophet Mohammed also referred to black cumin as ‘the medicine to heal every disease but death’ (Datta et al., 2012). Black cumin was used not only in spiritual rituals but also as a natural drug for asthma, toothaches and insomnia (Botnick et al., 2012). Additionally, in first century Greece, Dioscórides and Hippocrates referred to N. sativa as ‘Malathion’ and used the seed to treat congestion and worms. Throughout Egyptian history, black cumin has been recorded as a beauty treatment as well as a mummification preservative. The Egyptians valued the seed so greatly that King Tutankhamun had a vial of the seed oil in his tomb for his journey ‘from life here to eternity’ (Padhye et al., 2008). Furthermore, the use of N. sativa has been recorded in other traditional writings such as the Ibn Sina, Canon of Medicine, Pliny the elder and traditional Chinese herbal books (Srinivasan, 2018). Currently, N. sativa is sold in many mosques in small containers and taken as the ‘remedy of the prophet’ representing healing, dignity and honour (Schmall, 2007).
Current Societal Importance
More recently, N. sativa has grown from being a spice in traditional food dishes to being commercially marketed in soaps, health foods, nutraceuticals, oils, and skin care products (GMI, 2019a). Black cumin is made up of more than a hundred identified chemical compounds and thousands of others that have yet to be discovered (Ahmad et al., 2013). Some of the identified chemical compounds include; eight essential amino acids, carotene, linoleic and linolenic acid, iron and potassium (Schmall, 2007). Claimed as a treatment for various illnesses, N. sativa contains Thymoquinone (TQ), which is thought to give black cumin its medicinal properties. The mode of action of TQ on the body remains unknown but is hypothesized to suppress inflammation. Thus, it is effective in treating symptoms of asthma and rheumatoid arthritis and improving the health of digestive, cognitive and epidermal systems. It also has antioxidant properties through its radical scavenging abilities, which reduce oxidative stress and free radical production. TQ as well as carvacrol, t-anethole, thymol and dihydrothymoquinone (DHTQ) are predicted to have anti-cancerous properties. TQ has been demonstrated to have the ability to decrease tumor growth in rats (Padhye et al., 2008). Due to this, black cumin has been used in combination with saffron or cysteine to ease the effects of chemotherapeutics (eMedicine, 2019). Currently, N. sativa oil is used in treating headaches, diabetes, hemorrhoids, allergies, bronchitis, emphysema and digestive disorders (Ahuja and Singh, 2019).
Figure 4: Major chemical compounds proposed to impart medicinal properties of N. sativa seeds
Image Source: Rahmani et al., 2014
Conversely, topological application or over consumption of N. sativa oils and seeds can cause adverse effects, which vary depending on the individual. Adverse effects include rash, allergic reactions, dermatitis, vomiting, and sleepiness. At high concentrations, N. sativa can negatively affect the liver and kidneys (Datta et al.,2012).
Economics and Trade
The ancient Assyrians and Copts discovered the medicinal properties of N. sativa (Srinivasan, 2018). Persian and Turkish merchants brought black cumin to Egypt during the New Kingdom. The Egyptians then inherited the seed as a key component in traditional culinary dishes and beauty practices; it was unknown if they used N. sativa for medicine (Datta et al., 2012). It was not until black cumin was marketed as a cosmetic that it gained popular demand in Western civilizations (Srinivasan, 2018).
Commonly sold as Black Seed Oil, N. sativa market was valued at $15.84 million USD in 2018 and is predicted to grow to $25 million USD by 2025 (GMI, 2019b). The three largest markets for N. sativa are nutraceuticals, cosmetics and food industries. As the demand grows for natural medicine containing organic and non-toxic ingredients, black cumin is predicted to play a prominent role in the future growth of the nutraceutical industry. On a global scale, nutraceuticals are predicted to pass $550 billion USD in value by 2025 due to increasing preference for natural products in India, China and Japan. Escalating demand in China is likely to increase the sale of nutraceuticals containing black cumin by 7% , surpassing 10 million USD by 2025 (Ahuja and Singh, 2019). In the US alone, the N. sativa nutraceutical market may increase over 130 tonnes by 2025 (GMI, 2019b). Both the N. sativa cosmetic and pharmaceutical industry is predicted to grow 6% due to an increase in the use of natural, anti-allergenic products that treat various skin ailments (Ahuja and Singh, 2019). Finally, functional foods have become a key element in combatting nutrient deficiencies around the world. The addition of N. sativa to food gives organic, low calorie and nutrient dense additives to any food. With Asia Pacific’s growing populations, the need for functional foods is rising. Black cumin provides a range of positive health benefits and is therefore likely to be added to functional foods, thereby stimulating growth of N. sativa products.
Currently there is limited information regarding trade value that is outlined in online reports or sources. This may be due to its lack of cultivation in North America or undisclosed information due to company policies. The major sources for black cumin seeds are India and Israel due to their favourable climates and developed N. sativa agricultural practices (GMI, 2019a). In the future, the United States and European countries will likely resort to self-production of black cumin. Currently, India, Indonesia, Singapore, Malaysia, Sri Lanka and others lead as the top exporters as well as manufacturers of the black cumin seedoil market followed by North America and Europe (Ahuja and Singh, 2019).
North America, Europe and Pacific Asia are large drivers for the Black Cumin oil market. An increase in oil market size is attributed to N. sativa plantations in South Korea, Australia and Japan (Ahuja and Singh, 2019). In America, there is a growing product demand for naturally sourced products. Some of the black cumin market drivers are health benefits, online retailers, diversification of applications and consumer demand (GMI, 2019b). The United States and China are the largest consumers for black cumin essential oils and aroma therapies. South Asian countries are the largest consumer of raw black cumin seeds. Most of the individuals purchasing products containing N. sativa are millennials, naturopaths and Gen X. These consumer groups purchase N. sativa products in the form of liquid, capsules, soft gels and powders to increase performance, physical improvements and mental health (Ahuja and Singh, 2019). N. sativa liquid has had the most significant market share and is projected to remain one of the largest administrative substance options in the future, alongside oil capsules that are predicted to exceed $1.5 million USD by 2025 (Market Watch, 2019). Europe has tightly regulated the use of synthetic chemicals for cosmetics as well as pharmaceuticals, which increases cosmetic and personal care import demands for organic ingredients, including N. sativa. Personal care and cosmetic products containing N. sativa are projected to reach over 700 tonnes by 2025, with the black seed oil market hitting $25 million USD by 2025 (Ahuja and Singh, 2019). As the consumer demands continue to increase, the black cumin market will continue to grow and accumulate value.
In the future, research aimed towards decreasing the misidentification of black cumin through education on proper identification is needed in order to decrease the risk of contamination. In addition, identification of the active components within the oil and seeds as well as their mode of action is crucial for further continuation of research and enhancement of the medicinal properties of black cumin. Further research into the medicinal constituents of N. sativa may be beneficial in the creation of new medications and chemotherapeutics (eMedicine, 2019). As previously mentioned, Thymoquinone (TQ) is the main compound of N. sativa. In addition to TQ there are other compounds that make up majority of the aromatic amines (Botnicket al., 2012). Continued research into the isolation and function of TQ will allow for an increase in the production of synthetic analogues that can be manufactured on a commercial scale and used as alternative medicine (Padhye et al., 2008). Moreover, further assessments of the safety of black cumin for various cosmetic and personal care products are needed for the prevention of adverse reactions and safety regulations. Black cumin seeds have had a long history of use in cosmetics, foods, medicine and various cultural rituals. As the popularity of N. sativa products continues to rise, the cultivation of black cumin will continue to grow to meet market demands.
About the Author
Emily McFaul is currently completing her degree in Biomedical Toxicology with a minor in Agriculture at the University of Guelph. She has a passion for learning about medicinal plants and current agricultural research. Emily hopes to further her education in graduate school studying plant pathology or horticulture.