Herb of the Month – Nigella sativa and Thyroid Health

🌿 This month’s Herb of the Month is Nigella sativa
Family: Ranunculaceae

🌿 Description:

Nigella sativa, commonly known as Black Cumin, is a flowering annual that grows between 20-90 centimetres tall with finely divided leaves, large, black, seed-filled fruits and delicate flowers that range in hue from white through to yellow, pink or pale blue/purple. The plant appears to be native to the eastern Mediterranean region, northeastern Africa and southwestern Asia but has been widely cultivated for both culinary and medicinal purposes and has been naturalised in many areas throughout the globe. It is generally considered that the essential oil, particularly its thymoquinone component, is the most significant active constituent of Black Cumin (2) and also lends the seeds and their pressed oil an intensely lemony, peppery and caraway-like flavour profile that is prized in many traditional and modern cuisines.

🌿 History and traditional use:

Sites in Egypt and the region that was ancient Mesopotamia have yielded archaeological evidence, in the forms of botanical preparations and descriptive tablets, of the cultivation and culinary, medicinal and sacred uses of Black Cumin from as far back as 1324 BCE. It appears that the seeds were traditionally prepared in combination with honey, propolis and other bee products in many of these areas and were an important component of many internal and external medicinal preparations. There is also solid evidence of Black Cumin seeds featuring in sacred ceremonial preparations and even in burial offerings (3, 8).

In later history, Diocoredes described the many beneficial uses of ‘melanthion’; a plant now believed to be Black Cumin, in his De Materia Medica. In various preparation forms, including culinary combinations with vinegar, bread and other specific foods, he praised the plant as both a topical and internal agent to be used in a wide array of ailments from respiratory difficulties to toothaches and skin conditions (3). Black Cumin has even further reaching traditional use in the healing systems of India, the Arabic and Islamic regions, Iran and Sudan all indicating the plant for a multitude of symptoms and presentations of the respiratory, gastrointestinal and nervous systems (3, 8, 5).  

Whilst modern science has not gone so far as to qualify the prophet Mohammed’s proclamation that Black Cumin is a ‘medicine for all diseases’, there is a large body of strong preclinical data that supports a myriad of traditional actions of the herb, including antidiabetic, anticancer, analgesic, antimicrobial, spasmolyric, bronchdilatory, hepatoprotective, renoprotective and gastroprotective properties (2, 5).

🌿 Actions and indications:

Black Cumin has been shown to possess a particularly significant triad of antioxidant, antiinflammatory and immunomodulatory properties that, combined with the herbs’ collateral benefits, have clear and multifaceted indications for complex autoimmune conditions, including Hashimoto’s Thyroiditis and its associated symptoms.

Hashimoto’s Thyroiditis simply refers to the clinical presentation of painless thyroid enlargement and, on palpation, a ‘rubbery’-textured goitre. It is diagnostically associated with alterations in thyroxin (T4), Thyroid Stimulating Hormone (TSH) and thyroid antibodies and with significant oxidative stress and inflammatory markers, particularly over time (1). The majority of patients with a Hashimoto’s presentation experience symptoms of hypothyroidism, including:

  • Bradycardia
  • Cognitive decline
  • Cold intolerance
  • Constipation
  • Depression
  • Dry, coarse hair
  • Dry, thickened, scaly skin
  • Menstrual symptoms, including menorrhagia and amenorrhoea
  • Mood swings
  • Oedema and swelling
  • Weight gain

In fewer cases, Hashimoto’s manifests as hyperthroidism, producing virtually opposing symptoms including:

  • Frequent bowel movements
  • Heat intolerance
  • Hyperactivity
  • Insomnia
  • Menstrual symptoms, including hypomennorhoea
  • Nervousness
  • Palpitations and tachycardia
  • Sweating
  • Tremors
  • Weakness and fatigue

Our concern as practitioners is not only the management of the chronic inflammatory, oxidative and immunological aetiology of Hashimoto’s but also providing support for concurrent thyroid-related symptoms. For ease of clinical application, we could consider that the primary antioxidant, anti-inflammatory and immunomodulating actions of Black Cumin address the core aetiological issues of Hashimotos, while its array of secondary actions offers support for resulting thyroid function-related symptom pictures. This concept is supported by both human and preclinical data and significant recent results have sparked scientific interest in further exploring the specific application of Black Cumin seed preparations in Hashimoto’s Thyroiditis and other autoimmune disorders.

🌿 Science and clinical trials:

In 2016, a study on 40 patients with diagnosed Hashimotos Thyroiditis split the participants into two equal groups, who were administered either 2 grams of ground Black Cumin seeds or placebo daily for an eight-week trial period. At the conclusion of the trial, the study group showed significant reductions in body weight, body mass index (BMI) and waist-to-hip ratios when compared to placebo. The mechanisms for this effect were clearly tied to thyroid function as measured by correlating serum decreases in TSH and anti-thyroid peroxidases and increases in triidothyronine (T3) when compared to baseline (6).

While this study did not examine the specific mechanisms of action of Black Cumin beyond its effects on selected serum measurements, the herb has been extensively studied in a preclinical context and has demonstrated several potent actions that influence thyroid and immune health. A study on rats showed that isolated thymoquinone significantly reduced a spectrum of pro-inflammatory mediators and provided antioxidant protection (4). Another animal study showed that Black Cumin significantly influenced thyroid and reproductive hormones in healthy rats (7). Investigation of Black Cumin preparations on diabetic animals in laboratory studies demonstrated positively influential activity on serum insulin and glucose concentrations (8), both of these markers being implicated in the well-established development of insulin resistance in patients with autoimmune diseases, including Hashimotos (9). Ultimately, Black Cumin appears to exert several key actions useful in the treatment and support of autoimmune disorders, and future investigation of the herb is likely to be clinically significant.

🌿 Prescribing considerations:

As clinicians, we are always aiming to streamline our prescriptions and Black Cumin certainly appears to offer multiple potent actions that address the complexity of Hashimoto’s and other autoimmune pictures. Although ‘new’ to the modern Western herbal toolkit, we are likely to see the prescription of Black Cumin become a standard protocol in the management of these conditions.

🌿 References:

  1. MSD Manuals 2018, Merck Manual – Professional Version, Hashimoto Thyroiditis. Available at: << https://www.msdmanuals.com/en-au/professional/endocrine-and-metabolic-disorders/thyroid-disorders/hashimoto-thyroiditis>> Viewed 9th August 2018.
  2. Ahmad A, Husain A, Mujeeb M, Khan SA, Najmi AK, Siddique NA, Damanhouri ZA and Anwar F 2013, A review on therapeutic potential of Nigella sativa: A miracle herb, Asian Pacific Journal of Tropical Biomedicine, 3:5, pp. 337-352.
  3. Engels G and Brinckmann J 2017, Herbalgram – Nigella, The Journal of the American Botanical Council, 114, pp. 8-16.
  4. Umar S, Zargan J, Umar K, Ahmad S, Kativar CK and Khan HA 2012, Modulation of the oxidative stress and inflammatory cytokine response by thymoquinone in the collagen induced arthritis in Wistar rats, Chemico-biological Interactions, 197:1, pp. 40-46.
  5. Datta AK, Saha A, Bhattacharya A, Mandal A, Paul R and Sengupta S 2012, Black Cumin (Nigella sativa L.) – a review, Journal of Plant Development Sciences, 4:1, pp. 1-43.
  6. Farhangi MA, Dehghan P, Tajmiri S and Mesgari M 2016, The effects of Nigella sativa on thyroid function, serum Vascular Endothelial Growth Factor (VEGF) – 1, Nesfatin-1 and anthropometric features in patients with Hashimoto’s thyroiditis: a randomized controlled trial, BMC Complementary and Alternative Medicine, 16:471, pp. 1-9.
  7. Jasim WK, Hassan MS and Keam GG 2016, Study the effect of Nigella sativa on thyroid function and reproductive hormone of female rat, Journal of Contemporary Medical Science, 2:6, pp. 67-69.
  8. Sultana S, A HMAkhtar N, Iqbal A, Nazar H and Rehman RU 2015, Nigella sativa : Monograph, Journal of Pharmacognosy and Phytochemistry, 4:4, pp. 103-106.
  9. Varim C, Kaya T, Varim P, Nalbant A, Vatan MB, Yaylaci S, Gokosmanoglu F and Tamer A 2017, Biomedical Research India, 28:4, pp. 1543-1547.