What are nigella seeds?
The Muslim prophet Muhammad (PHUB) is reported to have said, "This black seed is healing for all diseases except death." The Persian polymath Ibn Sina, who was popularly known as Avicenna, also described the many benefits of the black seed in his encyclopedia, the "Canon of Medicine."1,2
In addition, the Egyptian Pharaoh Tutankhamun is said to have been buried with black seed oil as one of the items that will accompany him to the afterlife.3 This shows how the Egyptians revered the black seed and its extracts, a miracle-healing herb fit for kings.3
Black seeds as the name suggests are small black seeds that have a slightly peppery and aromatic flavour when chewed. Black seeds can be eaten as they are or cold pressed to produce an edible oil. The chemical constituents of black seed are responsible for its health benefits.2,3
The most abundant component is thymoquinone which is present in black seeds in a concentration of between 30 - 48%.2 Other compounds of interest that are found in black seeds include dithymoquinone, p-cymene (7-15%), carvacrol (6-12%), t-anethol (1-4%), sesquiterpene longifolene (1-8%), α-pinene, thymol, alkaloids, and alpha-hederin. Alpha-hederin which is an effective anti-cancer agent.2,3
Health benefits of nigella seeds
Immune boosting properties
The immune system protects us daily from pathogens (viruses, bacteria, fungi, etc.) we come in contact with in our environment. Therefore an immune system that works is essential to maintaining good health.
Thymoquinone in black seeds appears to have beneficial properties for the immune system. During the COVID-19 pandemic when researchers were looking for natural alternatives to pharmaceutical-grade medicines as options for the treatment of the SARS-CoV-2 virus which caused the COVID-19 pandemic, black seed was one of the options under study due to studies showing its effectiveness against viral infections.4
Additionally, inflammation within the body is bad for the immune system and contributes to the development of several chronic diseases such as heart disease, diabetes, arthritis, and lung disease. During the COVID-19 pandemic, inflammation was associated with poor outcomes, an increase in mortality, and the primary cause of admission to the intensive care unit in individuals who contracted the virus.4
Black seed as an oil or an extract has been shown to reduce inflammation through its action on components of the immune system that cause inflammation. In addition, it makes a particular subset of white blood cells called T-cells more effective in mounting an immune response to pathogens.4 White blood cells are the body's front-line defence against disease-causing pathogens.
Lowering blood sugar levels
The liver plays a role in the regulation of blood sugar levels by converting glucose from the blood and storing it as glycogen through a process known as glycogenesis. Thymoquinone present in black seeds acts on liver enzymes to increase the process of glycogenesis and also prevents the breakdown of glycogen stored in the liver to glucose. Both actions contribute to a reduction in blood sugar levels.2
Additionally, a study in patients with type 2 diabetes (T2DM) showed that consuming black seed oil in addition to taking oral anti-diabetic medicines resulted in better outcomes in terms of blood sugar reduction in the study population. This shows that black seed oil may have a role to play in the management of T2DM.2
Improving heart health
Thymoquinone in black seeds (oil and extract) also showed multiple beneficial effects on the heart in animal studies. Thymoquinone resulted in reductions in blood pressure, heart rate, and contractility in a similar way to commercially available pharmaceutical blood pressure medicines called calcium channel blockers.5
A significant reduction in blood pressure (systolic and diastolic) was observed in assigned male at-birth patients with high blood pressure and cholesterol who consumed black seeds daily for eight weeks.5 This blood-lowering effect was also observed in healthy volunteers who consumed black seeds mixed with honey.
Consuming black seeds as oil, powder, or just as it is, in combination with honey or nicotinic acid (vitamin B3) while eating a low-fat diet and exercising was also observed to increase the levels of good cholesterol (HDL), and, reduce the levels of bad cholesterol (LDL) and triglycerides in different groups of people.5
Animal and human studies using black seed oil showed that it can prevent the incidence of cancer and when cancer is present, its consumption was associated with a reduction in the size of tumours.1 These beneficial effects were observed in animal studies of colon cancer and human studies of individuals with breast cancer.1 The most researched component of N.sativa associated with this beneficial anti-cancer effect is thymoquinone.6 Another component of black seeds, alpha-hederin is an effective anti-cancer agent.2
Skin and hair benefits
Thymoquinone again may have a role to play in the management of vitiligo due to its ability to stimulate the activity of melanocytes. Melanocytes are the cells responsible for producing melanin, the pigment that determines how dark our skin gets. Thymoquinone can be used to pigment areas of skin in individuals with vitiligo.1
The Egyptian queen Cleopatra who is famous for her natural beauty secrets is said to have used black seed oil on her hair to keep it soft and silky.3 Black seed also finds use as a remedy for some forms of hair loss (alopecia).
Improving digestive health
It is said that gut health is a good indicator of overall health. Consuming black seeds in their various forms can protect from gastrointestinal diseases.7 The calcium content of black seeds helps protect against cancers affecting the organs of the digestive tract (colon, pancreas), and its copper content helps maintain the integrity of the intestinal wall by increasing the production of collagen, a component of the intestinal wall.7
Black seeds are also a rich source of soluble fibre, which aids digestion and supports healthy and regular bowel movement. Regular bowel movement aids in the elimination of toxic waste from the body, thus essential for optimal gut health.7
The antibacterial properties of black seeds are due to the most abundant components thymoquinone and melanin.2 Several studies have shown that extracts of black seeds are effective against disease-causing strains of bacteria with an antibacterial activity that is comparable to pharmaceutical-grade antibiotics.2
The antibacterial activity of black seeds appears to vary slightly between seeds from different geographical locations and the type of bacteria. Black seeds are more effective against bacteria that are classified as Gram-negative than those that are Gram-positive.2
Additionally, extracts of black seeds are effective against highly resistant strains of bacteria such as Methicillin-resistant staphylococcus aureus (MRSA) and possess anti-H. Pylori activity. H. pylori is a bacterium that causes stomach ulcers, the treatment usually involves the use of two antibiotics and a medicine that helps suppress stomach acid secretion. The anti-H-pylori activity of black seeds is comparable to the medicines currently used to kill the H.pylori bacteria.2
Studies carried out using the alcoholic extracts of black seeds showed significant activity against fungi that cause yeast infections (C.albicans). In addition, animal studies using extracts of black seeds showed up to an 11-fold reduction in the severity of infection in mice with candidiasis affecting several organs.2 This antifungal activity against the different types of fungi (yeasts and dermatophytes) is attributed to thymoquinone, thymohydroquinone, dithymoquinone, and quinines in black seeds.2
Antioxidant and anti-inflammatory activity
Antioxidants are agents that work to reduce the damage done to the body from oxidative stress. Oxidative stress is the result of the accumulation of free radicals in the body. Free radicals are chemicals produced by the different metabolic processes that occur in the body.2 Free radicals are highly reactive and can lead to damage affecting various organs.
The accumulation of free radicals is also linked to premature ageing, supports the development of an inflammatory state, which is bad for the body, and, contributes to the development of diseases such as cancer.2
Individuals are now more aware of the havoc free radicals can have on the body and are now making a conscious decision to add fruits, vegetables, and superfoods that are rich in antioxidants to their diet to reduce free radical damage.
The alcoholic extracts of the shoots, leaves, and seeds of black seed have good antioxidant and anti-inflammatory properties. Thymoquinone appears to boost the effectiveness of antioxidants and anti-inflammatory markers in the body.2
(see immune boosting properties and antioxidant and anti-inflammatory activity).
In addition to the chemical constituents of black seeds, black seeds also contain protein (26.7%), fats (28.5%), carbohydrates (24.9%), insoluble fibre (8.4%), copper, zinc, potassium, iron and beta carotene.2
Uses of nigella seeds
Cooking with nigella seeds
Heating or cooking black seed oil appears to reduce its health benefits. Black seeds can be:8
- Sprinkled onto salads
- Used to make salad dressings
- Baked on bread
- Used in stir-fry recipes
- Used in curries and dhal
- Made into tea
- Sprinkled onto yoghurt, oatmeal, etc.
Recommended daily intake of nigella seeds
The recommended quantity of black seed oil to take per day is 3 teaspoons, taking more than this will not give any additional health benefits instead it may irritate the stomach causing stomach discomfort.3
Side effects and other concerns
Cold-pressed oil from black seeds is very safe to consume. No negative effects on the organs or the normal functioning of the body were observed in both short and long-term animal studies.2
Despite this, the components of black seeds may interact with pharmaceutical-grade medicines due to their action on liver enzymes that are involved in the processing of medicines for absorption by the body and elimination from the body.2
If the effect is inhibition of these liver enzymes, this will prevent the breakdown of some medicines which will keep them in high concentration in the body, which can increase the risk of medicine-related side effects. If the effect is an increase in the activity of these liver enzymes, this will increase the rate of breakdown of medicines taken, making them less effective.2
Given the myriad of health benefits of black seed when consumed in its many forms, the saying “The black seed is healing for all diseases except death” is easily believable.
The black seed is ranked as one of the top-rated herbal remedies that are evidence-based and have a long history of use, dating back centuries. In addition, the low toxicity associated with its consumption adds to its benefit as a herbal remedy.
Animal and human studies have proven the many benefits of black seeds but despite this, caution needs to be emphasized due to the potential interaction between black seeds and certain pharmaceutical-grade medicines. More research needs to be done to determine to what degree this interaction happens to provide healthcare professionals with the relevant information so they can advise their patients. If you're considering adding black seed to your daily healthy living regimen, please discuss it with your GP, Pharmacist, or healthcare professional.
- Ali SA, Parveen N, Ali AS. Links between the Prophet Muhammad (PBUH) recommended foods and disease management: A review in the light of modern superfoods. Int J Health Sci (Qassim). 2018 Mar-Apr;12(2):61-69. PMID: 29599697; PMCID: PMC5870322.
- Ahmad A, Husain A, Mujeeb M, Khan SA, Najmi AK, Siddique NA, et al. A review on the therapeutic potential of Nigella sativa: A miracle herb. Asian Pacific Journal of Tropical Biomedicine [Internet]. 2013 May [cited 2023 Mar 27];3(5):337–52. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3642442/
- Team Erbology. How Much Black Seed Oil to Take and When - Erbology [Internet]. erbology. co. 2021 [cited 2023 Mar 27]. Available from: https://erbology.co/how-much-black-seed-oil-dosage/
- Kulyar MF, Li R, Mehmood K, Waqas M, Li K, Li J. Potential influence of Nigella sativa (Black cumin) in reinforcing immune system: A hope to decelerate the COVID-19 pandemic. Phytomedicine. 2021 May;85:153277.Epub 2020 Jul 10. PMID: 32773257; PMCID: PMC7347483.
- Shakeri F, Khazaei M, Boskabady MH. Cardiovascular Effects of Nigella Sativa L. and its Constituents. Indian Journal of Pharmaceutical Sciences. 2018 Sep 3;80(6)
- Shakeri F, Gholamnezhad Z, Mégarbane B, Rezaee R, Boskabady MH. Gastrointestinal effects of Nigella sativa and its main constituent, thymoquinone: a review. Avicenna J Phytomed. 2016 Jan-Feb;6(1):9-20. PMID: 27247918; PMCID: PMC4884214.
- Tremblay S. Digestive Benefits of Cumin Seed [Internet]. Healthy Eating | SF Gate. [cited 2023 Apr 4]. Available from: https://healthyeating.sfgate.com/digestive-benefits-cumin-seed-10474.html
- Masterclass. How to Eat and Cook With Nigella Seeds [Internet]. masterclass.com. 2021 [cited 2023 Mar 27]. Available from: https://www.masterclass.com/articles/how-to-eat-and-cook-with-nigella-seeds