Cinnamon’s Sweet Secret: The Spice that Helps Lower Blood Sugar

Cinnamomum zeylanicum

Ancient Use

There are two major varieties of cinnamon: Ceylon or true cinnamon (Cinnamomum zeylanicum), grown in Sri Lanka and Southern India, and cassia (Cinnamomum aromaticum), which is cultivated in China, Indonesia, and Vietnam. For thousands of years, cinnamon has been used in traditional medicine in Egypt, China, and India. Beyond its role as a flavorful spice, it has been valued as an herbal remedy for common colds, cardiovascular diseases, blood sugar reduction and gastrointestinal ailments (1).

In this article, I will explore cinnamon's potential to decrease elevated blood sugar levels, a defining characteristic of uncontrolled diabetes—an increasingly prevalent disease worldwide.

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Relevant Biochemical Pathway: GLUT4

The biochemical mechanisms by which our body regulates blood sugar through hormones like insulin and glucagon are intricate, with ongoing discoveries deepening our understanding. I will primarily focus on one key aspect of blood sugar regulation: GLUT4.

GLUT4 is a sugar transporter protein that facilitates glucose transport across cell membranes, primarily in fat tissue and skeletal muscle. Both insulin and exercise acutely stimulate GLUT4 recruitment to muscle and adipose cell surfaces. During physical activity, GLUT4 expression increases, fusing with muscle cell membranes to allow glucose uptake from the bloodstream, thereby lowering blood sugar levels while fueling muscle activity. In diabetes mellitus, GLUT4 expression is reduced due to insulin deficiency or insensitivity, impairing glucose uptake (2,3). A schematic representation of GLUT4 (4) is presented below

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Cinnamaldehyde

Cinnamon contains unique polyphenols that have been shown in vitro to enhance insulin-dependent glucose metabolism approximately 20-fold (5). Animal studies further suggest cinnamon’s role in blood sugar regulation. A study on diabetic rats found that cinnamon bark extract significantly reduced body weight while increasing insulin levels and lowering blood sugar (6).

Cinnamaldehyde, one of cinnamon’s active compounds, is able to play a key role glucose metabolism. Studies in mice show that cinnamaldehyde increases GLUT4 expression in muscle cells (7). Further research indicates that this compound enhances GLUT4 expression by stimulating mitochondria within muscle tissue (8). Additionally, diabetic rats treated with cinnamaldehyde exhibited reduced blood sugar levels, decreased Hemoglobin A1c (HbA1c), and improved cholesterol, triglyceride, and liver enzyme levels (9). Another study found that a single dose of cinnamaldehyde reduced food intake and slowed gastric emptying (10), similar to the mechanism of the weight-loss drug Ozempic (semaglutide).

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Human Clinical Studies

Several human studies support cinnamon’s ability to improve glucose metabolism and prevent diabetes. Here are three well-conducted studies:

• Placebo controlled Trial - 60 Middle-Aged Individuals with Type 2 Diabetes (11):

  • Participants received either a placebo or daily doses of 1g, 3g, or 6g of cinnamon, taken immediately after meals for 40 days, followed by a 20-day washout period.

  • Only the 6g group showed reduced blood sugar after 20 days, but all cinnamon groups had lower levels by day 40.

  • The effect persisted even 20 days after stopping cinnamon consumption

• Double-Blind Placebo-Controlled Trial - 99 Participants w/ Type 2 Diabetes (12):

  • Participants took either 500 mg cinnamon capsules or a placebo three times daily after meals for 60 days.

  • The cinnamon group significantly reduced fasting blood sugar from 153 mg/dl to 132 mg/dl.

  • Improvements were also observed in systolic and diastolic blood pressure.

  • HbA1c decreased from an average of 8.0% to 7.6%.

• Double-Blind Placebo-Controlled Trial- 79 Participants w/ Type 2 Diabetics (13):

  • Participants consumed 1g of cinnamon three times daily (3g total/day) for 4 months.

  • Fasting blood sugar decreased by ~10% from 9.26 mmol/L (166 mg/dl) to 8.15 mmol/L (147 mg/dl), compared to a 3% decrease in the placebo group.

  • No statistically significant reduction in HbA1c was observed, suggesting cinnamon may be more effective in lowering HbA1c in individuals with higher baseline HbA1c levels like the study above.

A separate randomized controlled trial of over 100 diabetic patients with an average HbA1c of 8.3% found that taking 1g of cinnamon daily for 90 days reduced HbA1c by 0.83%, compared to a 0.37% reduction in the control group (14).

These findings suggest that daily cinnamon consumption can significantly reduce blood sugar levels in all participants and lower HbA1c in more severe diabetics, which can mitigate common complications of diabetes such as nerve damage, kidney disease, eye problems, and cardiovascular issues (15).

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Cinnamon as a Natural Alternative to Ozempic?

Ozempic (semaglutide) has gained widespread attention as a weight-loss drug, though it has been used for years to treat type 2 diabetes. It works by activating glucagon-like peptide-1 (GLP-1), delaying gastric emptying and reducing appetite (15).

Intriguingly, a study on healthy individuals who consumed 3g of cinnamon in rice pudding found a resultant increase in GLP-1 levels (17). While no immediate appetite suppression was observed (likely due to the study’s short duration), cumulative effects over time could lead to weight loss. While cinnamon’s GLP-1 activity is not as potent as Ozempic’s, it may offer a natural, side-effect-free alternative for metabolic health.

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Ceylon vs. Cassia: Which is Better?

Ceylon cinnamon has a sweeter, more floral flavor, while cassia is stronger and more pungent. A key difference lies in their chemical composition: Cassia contains higher levels of coumarin, which, in very large amounts, can be toxic to the liver and kidneys (18). Ceylon cinnamon, on the other hand, has negligible coumarin levels and contains additional beneficial phytochemicals such as linalool (which will be discussed in a future article on lavender!).

For those consuming significant amounts of cinnamon for glycemic control, Ceylon cinnamon is likely the safer choice

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Final Thoughts & Recommendations

I would be remiss if I did not mention the most effective, scientifically proven method for preventing diabetes: regular exercise. While medical interventions are valuable, exercise remains unparalleled in its ability to improve glucose uptake, insulin sensitivity, fat metabolism, and mental health. The evidence for this is substantial and this is because of how our bodies evolved over thousands of years. The recommended guideline for preventing/treating type 2 diabetes is 2.5 hours of exercise per week (20, 21, 22).

Cinnamon can be taken in capsule form or added to foods like yogurt, smoothies, or pudding. Taking cinnamon with each meal appears to be most effective for controlling blood sugar.

To optimize glucose control and prevent/improve diabetes, my recommendation is:

• Engage in 30 minutes of exercise, 5 days a week.

• Take 500 mg - 1g of Ceylon cinnamon with each meal (1.5g - 3g daily total).

• Monitor fasting glucose and HbA1c levels regularly with your healthcare provider.

• If you are already on diabetes treatment with either oral anti-hyperglycemics or insulin, the addition of cinnamon is likely safe but talk with your healthcare provider prior to starting regular cinnamon use and check your sugars regularly.

By implementing these proactive measures, along with a healthy diet, individuals can significantly reduce their risk of diabetes and its life-threatening complications.

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References:

1. Hamidpour R, Hamidpour M, Hamidpour S, Shahlari M. Cinnamon from the selection of traditional applications to its novel effects on the inhibition of angiogenesis in cancer cells and prevention of Alzheimer's disease, and a series of functions such as antioxidant, anticholesterol, antidiabetes, antibacterial, antifungal, nematicidal, acaracidal, and repellent activities. J Tradit Complement Med. 2015 Jan 16;5(2):66-70. doi: 10.1016/j.jtcme.2014.11.008. PMID: 26151013; PMCID: PMC4488098.

2. Huang S, Czech MP. The GLUT4 glucose transporter. Cell Metab. 2007 Apr;5(4):237-52. doi: 10.1016/j.cmet.2007.03.006. PMID: 17403369.

3. Medagama AB. The glycaemic outcomes of Cinnamon, a review of the experimental evidence and clinical trials. Nutr J. 2015 Oct 16;14:108. doi: 10.1186/s12937-015-0098-9. PMID: 26475130; PMCID: PMC4609100.

4. https://commons.wikimedia.org/wiki/File:Insulin_glucose_metabolism.jpg

5. Isolation and Characterization of Polyphenol Type-A Polymers from Cinnamon with Insulin-like Biological ActivityRichard A. Anderson, C. Leigh Broadhurst, Marilyn M. Polansky, Walter F. Schmidt, Alam Khan, Vincent P. Flanagan, Norberta W. Schoene, and Donald J. Graves Journal of Agricultural and Food Chemistry 2004 52 (1), 65-70 DOI: 10.1021/jf034916b

6. Jia Q, Liu X, Wu X, Wang R, Hu X, Li Y, Huang C. Hypoglycemic activity of a polyphenolic oligomer-rich extract of Cinnamomum parthenoxylon bark in normal and streptozotocin-induced diabetic rats. Phytomedicine. 2009 Aug;16(8):744-50. doi: 10.1016/j.phymed.2008.12.012. Epub 2009 May 22. PMID: 19464860.

7. Nikzamir A, Palangi A, Kheirollaha A, Tabar H, Malakaskar A, Shahbazian H, Fathi M. Expression of Glucose Transporter 4 (GLUT4) is Increased by Cinnamaldehyde in C2C12 Mouse Muscle Cells. Iran Red Crescent Med J. 2014 Feb;16(2):e13426. doi: 10.5812/ircmj.13426. Epub 2014 Feb 4. PMID: 24719730; PMCID: PMC3965863.

8. Gannon NP, Schnuck JK, Mermier CM, Conn CA, Vaughan RA. trans-Cinnamaldehyde stimulates mitochondrial biogenesis through PGC-1α and PPARβ/δ leading to enhanced GLUT4 expression. Biochimie. 2015 Dec;119:45-51. doi: 10.1016/j.biochi.2015.10.001. Epub 2015 Oct 9. PMID: 26449747.

9. Subash Babu P, Prabuseenivasan S, Ignacimuthu S. Cinnamaldehyde--a potential antidiabetic agent. Phytomedicine. 2007 Jan;14(1):15-22. doi: 10.1016/j.phymed.2006.11.005. Epub 2006 Nov 30. PMID: 17140783.

10. Camacho S, Michlig S, de Senarclens-Bezençon C, Meylan J, Meystre J, Pezzoli M, Markram H, le Coutre J. Anti-obesity and anti-hyperglycemic effects of cinnamaldehyde via altered ghrelin secretion and functional impact on food intake and gastric emptying. Sci Rep. 2015 Jan 21;5:7919. doi: 10.1038/srep07919. PMID: 25605129; PMCID: PMC4300502.

11. Khan A, Safdar M, Ali Khan MM, Khattak KN, Anderson RA. Cinnamon improves glucose and lipids of people with type 2 diabetes. Diabetes Care. 2003 Dec;26(12):3215-8. doi: 10.2337/diacare.26.12.3215. PMID: 14633804.

12. Sengsuk C, Sanguanwong S, Tangvarasittichai O, Tangvarasittichai S. Effect of cinnamon supplementation on glucose, lipids levels, glomerular filtration rate, and blood pressure of subjects with type 2 diabetes mellitus. Diabetol Int. 2015 Jul 9;7(2):124-132. doi: 10.1007/s13340-015-0218-y. PMID: 30603255; PMCID: PMC6225001.

13. Mang B, Wolters M, Schmitt B, Kelb K, Lichtinghagen R, Stichtenoth DO, Hahn A. Effects of a cinnamon extract on plasma glucose, HbA, and serum lipids in diabetes mellitus type 2. Eur J Clin Invest. 2006 May;36(5):340-4. doi: 10.1111/j.1365-2362.2006.01629.x. PMID: 16634838.

14. Crawford P. Effectiveness of cinnamon for lowering hemoglobin A1C in patients with type 2 diabetes: a randomized, controlled trial. J Am Board Fam Med. 2009 Sep-Oct;22(5):507-12. doi: 10.3122/jabfm.2009.05.080093. PMID: 19734396.

15. Stratton IM, Adler AI, Neil HA, Matthews DR, Manley SE, Cull CA, Hadden D, Turner RC, Holman RR. Association of glycaemia with macrovascular and microvascular complications of type 2 diabetes (UKPDS 35): prospective observational study. BMJ. 2000 Aug 12;321(7258):405-12. doi: 10.1136/bmj.321.7258.405. PMID: 10938048; PMCID: PMC27454.

16. Gastrointestinal effects of GLP-1 receptor agonists: mechanisms, management, and future directions. Jalleh, Ryan J et al. The Lancet Gastroenterology & Hepatology, Volume 9, Issue 10, 957 - 964

17. Hlebowicz J, Hlebowicz A, Lindstedt S, Björgell O, Höglund P, Holst JJ, Darwiche G, Almér LO. Effects of 1 and 3 g cinnamon on gastric emptying, satiety, and postprandial blood glucose, insulin, glucose-dependent insulinotropic polypeptide, glucagon-like peptide 1, and ghrelin concentrations in healthy subjects. Am J Clin Nutr. 2009 Mar;89(3):815-21. doi: 10.3945/ajcn.2008.26807. Epub 2009 Jan 21. PMID: 19158209.

18. Ranasinghe P, Pigera S, Premakumara GA, Galappaththy P, Constantine GR, Katulanda P. Medicinal properties of 'true' cinnamon (Cinnamomum zeylanicum): a systematic review. BMC Complement Altern Med. 2013 Oct 22;13:275. doi: 10.1186/1472-6882-13-275. PMID: 24148965; PMCID: PMC3854496.

19. https://www.pureleven.com/ceylon-cinnamon-vs-cassia-cinnamon/

20. Charatan F. Exercise and diet reduce risk of diabetes, US study shows. BMJ. 2001 Aug 18;323(7309):359. PMID: 11509418; PMCID: PMC1120973.

21. Colberg SR, Sigal RJ, Fernhall B, Regensteiner JG, Blissmer BJ, Rubin RR, Chasan-Taber L, Albright AL, Braun B; American College of Sports Medicine; American Diabetes Association. Exercise and type 2 diabetes: the American College of Sports Medicine and the American Diabetes Association: joint position statement. Diabetes Care. 2010 Dec;33(12):e147-67. doi: 10.2337/dc10-9990. PMID: 21115758; PMCID: PMC2992225.

22. Flores-Opazo M, McGee SL, Hargreaves M. Exercise and GLUT4. Exerc Sport Sci Rev. 2020 Jul;48(3):110-118. doi: 10.1249/JES.0000000000000224. PMID: 32568924.

Images:

https://www.pexels.com/photo/cinnamon-sticks-71128/

https://www.pickpik.com/cinnamon-sticks-ground-spice-food-ingredient-127196

https://www.picturethisai.com/care/Cinnamomum_verum.html

https://www.picturethisai.com/wiki/Cinnamomum_iners.html

https://en.wikipedia.org/wiki/GLUT4#/media/File:Insulin_glucose_metabolism_ZP.svg