8 Fascinating Health Benefits of Black Cumin Seed
Most people are familiar with the health benefits of popular and common seeds like flax, chia, hemp, sunflower, pumpkin, and others, but another seed with a long history of use is becoming more prevalent again — black seed. Known scientifically as Nigella sativa, black seed (or black cumin seed) is native to southwest Asia and comes from an annual flowering plant. It has an unusually complex flavor, with notes of sweetness, bitterness, smokiness, and nuttiness all tumbling around each other as the seeds are chewed. This flavor reflects the powerful compounds present in black seed. If you want to take your health to the next level, black seed is an amazing ally to have.
Nutrients in Black Seed
Black seed has a fascinating nutritional composition, with almost equal amounts of protein, fat, and carbohydrates. A small 5g serving of black seed delivers 2 grams of fat, 2 grabs of carbohydrates, and 1 gram of protein. Minerals such as zinc, copper, iron, phosphorous, potassium, magnesium, and calcium are also present, as is the carotene form of Vitamin A. However, the chief benefits of black seed appear to derive from the presence of advanced bioactive compounds such as quinones, terpenes, sterols, and alkaloids. The most important of these compounds include thymoquinone, thymohydroquinone, dithymoquinone, 4-terpineol, carvacrol, p-cymene, t-anethol, longifolene, thymol, alpha-pinene, nigellicimine, nigellidine, and nigellicine. Of these, thymoquinone is purported to be most responsible for black seed’s effects, which makes sense as it accounts for 30–48% of the weight of black seed’s secondary metabolites (the non-protein, non-fat, non-carbohydrate molecules). Just seeing such a list of intriguing compounds is exciting, but what really matters are the studies showing the impact of black seed on human health.
Health Benefits of Black Seed
1. Cardiovascular Health and Blood Sugar Control
A surprising number of clinical trials have pointed to the benefits of black seed or black seed oil on measures of cardiovascular health. A helpful review article from 2016 analyzed the results from 17 randomized controlled trials, and found that black seed was significantly associated with reducing total cholesterol and triglyceride levels. Interestingly, black seed oil had a stronger effect on reducing these levels than black seed powder, yet only the powder was capable of increasing good HDL cholesterol. For the most powerful results, combining seed oil and whole black seed may be optimal, although more research is needed to clarify this.
A 2008 clinical trial of patients with insulin resistance syndrome determined the black seed oil (2.5mL twice daily for 6 weeks) was additively effective in lowering total cholesterol and blood sugar levels when added to standard pharmaceutical therapy. Researchers concluded, “[Black seed] oil was found to be effective as an add-on therapy in patients of insulin resistance syndrome. [Black seed] oil has a significant activity in diabetic and dyslipidemic patients.” A similar trial in 2012 which added black seed to standard blood sugar control therapy found that the seed was a safe and effective add-on therapy for reducing blood sugar.
A 2011 trial in the Journal of Applied Sciences Research used black seed tea as the intervention modality to study impacts on blood sugar in 41 Type 2 diabetes patients. 5g of the tea per day for 6 months resulted in a highly significant decrease in blood sugar levels and other diabetic parameters like HbA1c levels. Interestingly, three patients in the trial were able to discontinue their conventional antidiabetic drug as the black seed worked well enough.
A trial conducted at King Faisal University in Saudi Arabia administered 1, 2, or 3g of black seed for 3 months to Type 2 diabetes patients to examine potential synergy with their conventional medications. 2g was the ideal dose, as 1g was not very effective and the 3 gram dose produced results similar to the 2 gram dose. Beneficial results observed included significantly reduced blood sugar levels, lower HbA1c, less insulin resistance, and improved function of beta-cells in the pancreas.
Black seed may be even more effective when paired with other botanicals like turmeric. A double-blind, placebo-controlled clinical trial carried out by researchers in Pakistan tested black seed and turmeric, alone and combined, in patients with metabolic syndrome (comprising the combination of symptoms of obesity, high blood pressure, high cholesterol, and insulin resistance). Black seed at 1.5g per day for 8 weeks was effective in reducing body-mass index, weight circumference, body fat percentage, and cholesterol, but the combination of black seed with turmeric allowed similar effects at lower doses (900mg black seed and 1.5g turmeric per day) while also ameliorating the inflammatory marker C-reactive protein.
Some trials have specifically examined the utility of using black seed for weight loss. A double-blind, placebo-controlled trial published in the journal Phytotherapy Research combined 3g black seed oil per day or placebo with a low-calorie diet for 8 weeks. Obese women who received black seed experienced more weight loss than those who only followed the dietary changes. Another very similar trial by the same team demonstrated further that black seed oil could reduce weight and waist circumference more significantly than placebo when combined with a low-calorie diet. Cholesterol and triglyceride levels also fell more in the treatment group than the placebo group.
High blood pressure alone is a serious risk factor for heart attacks and strokes, so natural modalities to reduce it are welcome. Two clinical trials specifically focused on blood pressure have found good results from black seed administration. First, a 2008 double-blind, placebo-controlled trial carried out at Shahrekord University of Medical Sciences in Iran determined that either 100mg or 200mg black seed extract twice daily for 8 weeks significantly reduced both systolic and diastolic blood pressure in patients with mild hypertension. Total cholesterol was also reduced.
Another trial carried out in Iran, this time at the Institute of Medicinal Plants, further confirmed the blood pressure-lowering effects of black seed. The 2013 double-blind, placebo-controlled trial examined the impact of black seed oil on blood pressure in health patients, finding that 2.5mL twice per day for 8 weeks reduced systolic and diastolic blood pressure without side effects. The process of transitioning into menopause is known as perimenopause, and women going through it can often experience metabolic changes associated with hormone fluctuations. A 2014 clinical trial which followed perimenopausal women in Malaysia found that administering 1.6g per day of powdered black seed for 12 weeks lowered LDL cholesterol and blood sugar levels, along with mitigating symptoms of perimenopause and improving quality of life. Researchers concluded, “These results suggested that treatment with [black seed] exerts a therapeutic and protective effect by modifying weight gain, improving lipid profile and blood glucose as well as hormonal level which is believed to play an important role in the pathogenesis of metabolic syndrome during menopause.”
2. Anti-Inflammatory and Antioxidant Effects
The anti-inflammatory and antioxidant benefits of black seed or thymoquinone have been demonstrated in numerous studies. A 2012 study by researchers with Hamdard University in India examined how thymoquinone affected rats with chemical-induced arthritis. The compound effectively reduced levels of several pro-inflammatory mediators, including various interleukins, tumor necrosis factor-alpha, interferon-gamma, and prostaglandin E2, while increasing the anti-inflammatory interleukin-10 and levels of antioxidant defenses. Physical measures including bone analysis also revealed anti-arthritic benefits.
An earlier study in 2005 by researchers with the same University above found that black seed could suppress chemical-induced kidney damage in rats. Levels of oxidant enzymes and compounds like xanthine oxidase and hydrogen peroxide increased after the chemical’s administration, and were reduced following black seed administration. Antioxidant enzymes, which decreased in response to the kidney damage, were significantly recovered as well. Additionally, several other measures of kidney health were noted to have improved, including prevention of kidney tumor development.
A 2006 study in the International Journal of Pharmacology found that black seed was effective in reducing the oxidative damage caused by ingestion of rancid corn oil in rats. The seed improved levels of the natural antioxidant glutathione in the liver, kidneys, and heart. There was also less destruction of red blood cells. Cardamom seeds exhibited antioxidant properties too, but black seed was apparently stronger, as heart glutathione increased only in the black seed group. Another study in 2007 further supported the ability of black seed to increase glutathione levels in a model of oxidative stress in rats.
The anti-inflammatory and antioxidant effects of black seed are clearly relevant in humans. First, a controlled trial carried out at Cairo University in Egypt found that 500mg twice per day of black seed oil for one month decreased disease severity in rheumatoid arthritis patients, with the practical effects of reducing the number of swollen joints and shortening the duration of morning stiffness.
Allergies can cause rhinitis, inflammation of the nasal membranes, and many over-the-counter products like Singulair (montelukast) are routinely used to manage this inflammation. A 2010 trial compared the efficacy of black seed directly with montelukast for treating rhinitis, and found that 250mg per day of black seed significantly decreased daytime symptoms to a similar extent as montelukast. Interestingly, the seed was more effective than the drug for nighttime symptoms. The authors of the study concluded, “[Black seed] is safe and free from threat of serious adverse effects. So it is a reliable management alternative for seasonal allergic rhinitis patients.”
Another trial the next year lent more support to the use of black seed for rhinitis. The placebo-controlled trial conducted at Ahvaz Jundishapur University of Medical Sciences in Iran found that administering black seed oil to rhinitis patients could mitigate a wide variety of symptoms, including nasal congestion, itching, sneezing, runny nose, and more. While that trial and the vast majority of others involve oral ingestion, a 2014 trial also found that even topical application of black seed oil (1 drop per nostril 3 times a day for 6 weeks) could improve tolerability to allergen exposure in rhinitis patients.
Black seed does not need to be used alone and has been demonstrated to synergize with conventional therapies. A 2010 trial with rhinitis patients at Marmara University in Turkey discovered that combining black seed at 2g per day for 30 days along with immunotherapy was more effective than immunotherapy alone for improving immune parameters and apparently improving symptoms. The functions and numbers of certain white blood cells was enhanced in the black seed group, leading researchers to conclude that consuming black seed “during specific immunotherapy of allergic rhinitis may be considered a potential adjuvant therapy.”
Given the benefits for rhinitis, it is not surprising that a comparative study of topical black seed oil against a salt solution found that the oil was more effective for treating nasal dryness, obstruction, and crusting in geriatric individuals with age-associated nasal symptoms. The oil was equally effective as the salt solution for treating burning and itching.
A previously mentioned study on black seed oil and obesity also found that women in the treatment group had higher levels of the antioxidant enzyme superoxide dismutase, although total antioxidant capacity was unchanged between the treatment and placebo groups.
3. Emotional and Cognitive Benefits
The benefits of black seed for emotional and cognitive wellness have been demonstrated in two placebo-controlled trials at the University of Dhaka in Bangladesh. First, a 2013 trial that followed twenty elderly patients used 500mg black seed twice per day for nine weeks. Over half a dozen cognitive tests revealed that the supplementation was effective in improving memory, attention, and cognition. The next trial in 2014 examined younger individuals instead, between 14 and 17 years of age, and the impact of 500mg black seed per day for 4 weeks. Testing revealed that the intervention was effective in stabilizing mood, reducing anxiety, and improving cognition.
While specific details were lacking, a 2008 trial carried out in Pakistan provided initial evidence that 500mg of black seed per day could mitigate withdrawal effects in 35 patients with addiction to opioids. Given that withdrawal entails significant psychological and physical distress, the ability of black seed to reduce this distress in any significant way is quite powerful.
4. Liver Health
Substantial evidence suggests that black seed benefits the health of the liver. A double-blind, placebo-controlled clinical trial carried out in 2019 followed 50 patients with non-alcoholic fatty liver disease, who either underwent lifestyle modification with placebo or with the addition of 2 grams per day of black seed for 12 weeks. Measures of hepatic steatosis (fatty liver) were decreased in the black seed group, while insulin sensitivity increased. Given the improvement in insulin sensitivity, it is not surprising there was also a reduction in blood glucose and insulin levels as well. Researchers concluded, “In conclusion, our results indicate that daily intake of [2 grams black seed] plus lifestyle modification is superior to lifestyle modification alone in amelioration of insulin resistance and hepatic steatosis in patients with [non-alcoholic fatty liver disease].”
Infection with the hepatitis C virus can cause severe liver damage and associated symptoms. The highest prevalence of infection in the world is Egypt, which led Egyptian researchers with Beni-Suef University to examine the impact of black seed and ginger extracts, alone and together, on sixty volunteers with hepatitis C. The dose was of black seed was at least 500mg per day, and while the timeline was unclear, at the end of the study patients in the black seed group had less viral load and improved liver function. Combining black seed with ginger was even more effective. Researchers concluded, “In conclusion, administration of Nigella sativa and/or Zingiber officinale ethanolic extracts to HCV patients exhibited potential therapeutic benefits via decreasing viral load and alleviating the altered liver function, with more potent effect offered by the mixture.”
Chemotherapy can often cause liver damage as a side effect, and black seed may help prevent this effect. A placebo-controlled trial tracked 20 children with acute lymphoblastic leukemia who received chemotherapy and 80mg/kg per day of black seed and compared them to 20 children who only received placebo alongside the chemotherapy. Multiple markers of liver health were significantly better in the black seed group, which also had improved disease free survival (although overall survival was similar between the treatment and placebo groups).
A previously mentioned study on black seed tea ingestion (5 grams black seed per day for 6 months) and blood sugar control also found benefits for liver health, as blood bilirubin levels were highly decreased in the treatment group. Bilirubin is a breakdown product of red blood cells, and blood levels rise when the liver fails to clear it properly. Excessive levels can lead to fever, pain, and nausea, among other symptoms.
5. Antibacterial and Antifungal Effects
The presence of thymoquinone and other bioactive compounds in black seed appears to be responsible for its widespread antibacterial and antifungal effects. For example, both thymoquinone and the compound melanin were suspected to be responsible for the ability of black seed to inhibit the growth of Staphylococcus aureus, as shown in a 2011 cell study. An earlier study in 2000 found that extracts of black seed were effective against the growth of gram-negative and gram-positive bacteria, especially the former.
Methicillin-resistant Staphylococcus aureus (MRSA) is one of the most dangerous types of emerging pathogens, responsible for treatment-resistant infections in hospitals across the world. In 2008, researchers with the University of Health Sciences in Pakistan showed that an ethanol extract of black seed exerted inhibitory activity against several MRSA strains.
Helicobacter pylori (H. pylori) is a gram-negative bacteria that can cause stomach inflammation or ulcers following infection. A trial carried out at King Faisal University in Saudi Arabia compared the use of black seed and standard antibiotics for treating patients with confirmed H. pylori infection. 88 patients were split between four groups — the first received a combination of three antibiotics (clarithromycin, amoxicillin, and omeprazole), while the next three groups received 1g, 2g, or 3g black seed combined just with omeprazole. The triple therapy was most effective, successfully eradicating the infection in 82.6% of patients in the group, while the 2g + omeprazole group was the next most effective, eradicating infection in 66.7% of patients. Interestingly, the 1g and 3g groups had similar eradication results of 47.6% and 47.8%; however, symptoms of the infection improved in all groups to a similar extent. While the standard therapy was more effective, the practical efficacy of black seed in fighting bacterial infections was clearly demonstrated in this study.
Bacteria can develop resistance to antibiotics by forming biofilms, a collection of substances that comprise a protective layer around the bacteria. Thymoquinone alone was shown in a 2011 study to prevent biofilm formation by Staphylococcus aureus and S. epidermidis. The compound was also shown to directly kill these bacteria along with several other pathogenic species.
Studies have also indicated the antifungal potential of black seed, such as one study which found that methanolic and chloroform extracts, but not water extracts, inhibited the growth of Candida albicans. Another class of fungi known as dermatophytes, which require the skin protein keratin to grow, were shown to be susceptible to both black seed extract and thymoquinone in a 2005 study published in the Journal of Ethnopharmacology. Both treatments inhibited growth of eight species of dermatophytes, although thymoquinone was far more potent than whole black seed, while a standard antifungal drug was even stronger than both. Nonetheless, it was noted that this study supports the historical use of black seed to treat fungal skin infections. Black seed may even have use as a food preservative agent.
A 2010 study in the Journal of Food Protection tested thymoquinone and other black seed-derived quinones against six yeast species associated with dairy spoilage. The compounds were effective at inhibiting growth, which led researchers to posit that they could be used as natural preservatives for the dairy industry.
6. Asthma and Lung Health
The benefits of black seed extend to the respiratory system and can make a difference in the lives of patients with asthma. In a 2010 trial published in the journal Phytomedicine, black seed extract at 50 and 100mg/kg was compared to standard anti-asthmatic drugs. Both doses of extract were effective in improving five different measures of pulmonary function and acted as a bronchodilator. However, they were weaker than the standard pharmaceuticals.
A placebo-controlled trial in the journal Fundamental & Clinical Pharmacology further demonstrated the anti-asthma effects of black seed extract. The form of black seed used was quite unique, 15mL/kg of 0.1% boiled extract, and it was administered to 15 patients in the study group for 3 months. The effects were stark — all asthma symptoms improved, including a decrease in the frequency of symptoms, less chest wheezing, and better performance in pulmonary function tests. The improvements became greater over time. Those receiving black seed were also able to reduce both inhaled and oral anti-asthma drugs, including beta-agonists and corticosteroids.
A controlled trial conducted at Aligarh Muslim University in India, while only lasting 14 days, provided further evidence that black seed oil benefits lung health. 43 children received 0.1mL/kg of the oil per day during the study, which effectively improved two measures of lung health. Even victims of chemical warfare have been shown to benefit from black seed extract. A 2008 double-blind, placebo-controlled trial published in the Journal of Alternative and Complementary Medicine found that 0.375mL/kg black seed extract for 2 months resulted in improved lung function, less chest wheezing, and overall respiratory symptom improvement in the treatment group. Many patients were able to reduce inhaled and oral beta-agonists and corticosteroids use as well.
7. Gut Health
While there is not a tremendous amount of human research on black seed and the gut, what does exist is quite interesting. Two trials examined how black seed could potentially benefit patients with celiac disease, who exhibit excessive immune reactions after the ingestion of gluten from species of wheat. First, a 2012 trial found that combining black seed oil with a gluten free diet improved measures of blood and immune health, as well as alleviated iron deficiency.
Another trial in 2013 showed that adding black seed oil to a gluten free diet could help treat dermatitis herpetiformis, a painful skin rash condition associated with celiac disease. More research is needed to determine the potential benefits of black seed for gastrointestinal conditions like Crohn’s disease or irritable bowel syndrome.
8. Kidney Stones
The development of kidney stones occurs due to the buildup of minerals and salts inside kidneys, and these deposits must eventually be passed out through the urinary tract. It is notoriously painful, so any modalities that can reduce the impact of kidney stones are certainly welcome. The ability of black seeds to help treat this condition is particularly interesting. A 2011 study tested extracts of black seed on rats with chemical-induced kidney stones (also known as calcium oxalate deposits), finding that the extracts were effective in reducing the number and size of the stones. A previous study by the same team found that thymoquinone alone also decreased the number and size of stones in rats.
A triple-blind, placebo-controlled trial published in 2019 in the journal Phytotherapy Research clearly demonstrated the value of black seed administration in humans. Sixty patients were enrolled in the trial and received either 500mg encapsulated black seed twice per day or placebo for 10 weeks. The differences between the treatment and placebo groups were quite stark. Over 44% of treated patients completely excreted their stones, and over 50% of patients experienced decreased stone size. For those in the placebo group, only about 15% of patients passed their stones completely, and only 11.5% experienced decreased stone size. Therefore, black seed supplementation at just 1 gram per day was shown to have a beneficial effect on kidney stones.
The Future of Black Seed
As this research demonstrates, there are proven beneficial effects of black seed on human health. The results shown in the numerous placebo-controlled trials are stunning. However, a lot more research is needed to clarify the effects of long-term usage of black seed as well as effects from higher doses. More research into topical use would also be great. For example, cyclic mastalgia is a painful breast condition experienced by women due to hormonal fluctuations, and a 2016 triple-blind, placebo-controlled study found that black seed oil applied to the sites of pain was more effective than placebo and comparable to a non-steroidal anti-inflammatory drug in efficacy. It is quite possible the results would be even better if topical and internal use were combined, and future studies should examine this.
How to Use Black Seed
Black seed can be easily mixed into any yogurts, salads, cereals, and granolas, imparting its unique flavors into these foods. You can also get black seed oil, which can be used as part of a dressing for salads or mixed into coffees, teas, or any drinks. In seed form, I probably use just around 10–20 grams, and in oil form, I probably use around 1 to 2mL as the dressing or drink addition. Right now I am mainly using the oil because it is the quickest way to benefit from black seed’s powers, but the whole seeds have a fuller spectrum of nutrients and I try to incorporate them into my diet when possible. Nonetheless, I know that as long as I’m ingesting any form of black seed, it’s doing good for my health.
