Nigella Sativa Improves Fasting Blood Glucose and Insulin Response in Subjects with Type 2 Diabetes Mellitus

by | Nov 7, 2023 | 2019, Blood Sugar, Botanicals, Diabetes

Written by Taylor Woosley, Staff Writer. Findings from the systematic review of 9 studies show that Nigella sativa intervention significantly improved fasting blood glucose, blood glucose level 2hPG, HbA1c, insulin level, and insulin resistance.

diabetesDiabetes mellitus (DM) is a public health threat worldwide and leads to a 2-3-fold increased risk of all-cause mortality1. Type 2 diabetes (T2DM) is a metabolic, chronic disorder characterized by insulin resistance and elevated blood glucose levels2. Oxidative stress has been shown to compromise the two major mechanisms failing during diabetes which are insulin secretion and insulin action3.

Nigella sativa (NS) has previously been researched for the management of diabetes due to its anti-inflammatory, immunomodulatory, renal protective, and antioxidant properties4. Several reviews have shown that NS modulates hyperglycemia and lipid profile dysfunction via several mechanisms including its effects on insulin secretion, glucose absorption, and gene expression5. Furthermore, NS significantly reduced glucose values following oral glucose tolerance test, along with fasting plasma glucose, and hemoglobin A1c levels6.

Hamdan et al. conducted a systematic review to assess the efficacy of NS supplementation in combination with oral antidiabetic drugs on glucose and insulin profile status in diabetic subjects. Subject inclusion consisted of clinical human studies reporting the direct effects of NS on T2DM, following an observational, randomized control trial, double-blind randomized controlled trial, single-blind, or a non-randomized controlled trial design. Additionally, inclusion criteria focused on studies analyzing the effects of a crude plant preparation (in powder, oil, capsule, or tea form) and not its bioactive components reporting on at least one T2DM blood parameter, such as fasting blood glucose (FBG), HbA1c or blood glucose level 2 h postprandial (2hPG).

9 studies were included in the final analysis. 3 studies included treatment with NS oil, 2 used capsule form, 1 included NS powder, and 1 study focused on efficacy of NS tea. NS in oil form had a dose varying from 0.7 g/day, 3 g/day, and 5 mL/day. Capsule form had doses ranging from 1 to 3 g/day, while powder form and tea form were 2 g/day and 5 g/day, respectively. Blood samples used for analysis were FBG, 2hPG, HbA1c, insulin level, and insulin resistance. Significant findings of the systematic review are as follows:

  • Results from 6 studies measuring changes in FBG show that NS significantly decreased FBG levels.
  • 3 studies analyzing 2hPG parameters showed that 4 to 8 weeks of 2 g/day of NS capsules significantly decreased 2hPG. Furthermore, 5 gm/day NS tea for 6 months and 2.5 mL NS oil also significantly reduced blood glucose level 2hPG parameter.
  • 6 studies investigating changes in HbA1c show that 12-week treatment of 2 g/day and 3 g/day of NS capsules significantly decreased HbA1c levels. Furthermore, similar findings were noted for consumption of 5 gm/day of NS tea for 6 months.
  • 4 studies measuring insulin level and insulin resistance reported that treatment with NS oil for 40 days significantly increased insulin levels. Additionally, 2 g/day of NS capsules for 12 weeks significantly decreased insulin resistance and increased β-cell function.

Results of the study show that Nigella sativa significantly improved FBG levels, along with blood glucose level 2hPG, HbA1c, insulin level, and insulin resistance. Findings suggest that NS is an effective adjuvant therapy for T2DM subjects. Study limitations include the small study number involved and the use of multiple forms of NS at different dosages and durations.

Source: Hamdan, Amiza, Ruszymah Haji Idrus, and Mohd Helmy Mokhtar. “Effects of Nigella sativa on type-2 diabetes mellitus: a systematic review.” International journal of environmental research and public health 16, no. 24 (2019): 4911.

© 2019 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution
(CC BY) license (http://creativecommons.org/licenses/by/4.0/).

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Posted November 7, 2023.

Taylor Woosley studied biology at Purdue University before becoming a 2016 graduate of Columbia College Chicago with a major in Writing. She currently resides in Glen Ellyn, IL.

References:

  1. An Y, Xu BT, Wan SR, et al. The role of oxidative stress in diabetes mellitus-induced vascular endothelial dysfunction. Cardiovasc Diabetol. Sep 2 2023;22(1):237. doi:10.1186/s12933-023-01965-7
  2. Demir S, Nawroth PP, Herzig S, Ekim Üstünel B. Emerging Targets in Type 2 Diabetes and Diabetic Complications. Adv Sci (Weinh). Sep 2021;8(18):e2100275. doi:10.1002/advs.202100275
  3. Ighodaro OM. Molecular pathways associated with oxidative stress in diabetes mellitus. Biomedicine & pharmacotherapy = Biomedecine & pharmacotherapie. Dec 2018;108:656-662. doi:10.1016/j.biopha.2018.09.058
  4. Adam SH, Mohd Nasri N, Kashim M, Abd Latib EH, Ahmad Juhari MAA, Mokhtar MH. Potential health benefits of Nigella sativa on diabetes mellitus and its complications: A review from laboratory studies to clinical trials. Front Nutr. 2022;9:1057825. doi:10.3389/fnut.2022.1057825
  5. Mahomoodally MF, Aumeeruddy MZ, Legoabe LJ, Montesano D, Zengin G. Nigella sativa L. and Its Active Compound Thymoquinone in the Clinical Management of Diabetes: A Systematic Review. Int J Mol Sci. Oct 11 2022;23(20)doi:10.3390/ijms232012111
  6. Saadati S, Naseri K, Asbaghi O, et al. Nigella sativa supplementation improves cardiometabolic indicators in population with prediabetes and type 2 diabetes mellitus: A systematic review and meta-analysis of randomized controlled trials. Front Nutr. 2022;9:977756. doi:10.3389/fnut.2022.977756