Sections:

  1. Basic information
  2. Comparison of cinnamon varieties
  3. Cinnamon for diabetes
  4. Cinnamon as an anti-inflammatory and anti-oxidant
  5. Cinnamon for multiple sclerosis
  6. Cinnamon and Alzheimer's Disease
  7. Cinnamon and Cannabinoids
  8. Cinnamon in the garden
  9. Glossary
 10. References

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Basic Information

Cinnamon is so common now that it may be hard to believe what a mysterious spice it was at one time. It was in such great demand that spice traders kept their sources a secret for centuries. Wild stories about its origins abounded: it was said to be collected by "cinnamon birds" who used sticks of cinnamon to construct their nests, or it was found in far off canyons guarded by venomous snakes. Another myth claims it was obtained from the nest of the great phoenix. guarded by winged serpents and bats. Dutch explorers eventually discovered one variety, Cinnamomum zeylonicum, growing on the island of Ceylon and the monopoly of Arabian and Egyptian spice traders was broken.

The genus to which cinnamon belongs comprises over 250 species, with about 30 edible varieties. Only four are commonly sold for culinary use today:

• Cinnamomum zeylonicum or Cinnamomum verum: Ceylon cinnamon, sometimes called "true" cinnamon, and also known as Mexican cinnamon
• Cinnamomum cassia or Cinnamomum aromaticum, sometimes called Chinese cinnamon, the most common variety of cinnamon in US grocery stores
• Cinnamomum loureiroi, also known as Saigon or Vietnamese cinnamon
• Cinnamomum burmannii, Dutch or Korintje cinnamon

Another variety, Cinnamomum citriodorum, or Malabar cinnamon, is available from some specialty shops and online, but not commonly found elsewhere.

The herb sold as 'Indian bay leaf' is also actually a variety of cinnamon, Cinnamomum tamala.

Whatever its variety, the cinnamon sold as cinnamon powder and cinnamon sticks is the bark of a tree. It's peeled off in long strips, which curl as they dry into the typical "quills" sold as cinnamon sticks. C. cassia is the one most easily available in US supermarkets, but C. zeylonicum (C. verum) can be found in many health food stores, high end kitchen ware stores, onine and in specialty spice shops. Cinnamon's odor and flavor come from a wide range of compounds present in varying amounts in the different varieties. The one which gives cinnamon its characteristic flavor and scent is cinnamaldehyde, but several others-eugenol, cinnamic acid, and cinnamate, as well as procyanidins and catechins-contribute to its antioxidant and anti-inflammatory benefits.

Cinnamon essential oil may come either from the bark or from the leaves of the tree. Eugenol predominates in oil from the leaves, while cinnamaldehyde is the primary compound in oil from the bark. Both have a spicy sweet fragrance, but that from the bark is stronger. Some people characterize oil from the leaves as having a medicinal scent, but that may be because it's more often used to flavor over-the-counter pain remedies and other non-food items than the more expensive oil from the bark, and so is associated with those things. Both are extracted by steam or CO2 distillation. The yield is greater from cinnamon leaves, which means it is less expensive.

Besides its use in cooking, aromatherapy and as a flavoring in candies and snack foods, cinnamon has known therapeutic benefits. Like most other herbs and spices, though, there is a wealth of misinformation about it online. Here are some benefits that are known.

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Comparison of cinnamon varieties

Different online sources make different claims for the varieties, so comparisons can be confusing. Cassia cinnamon, the most common type sold in the US is sometimes described as Cinnamomum cassia, sometimes as Cinnamomum aromaticum, and in some sources as Indonesian cassia (Cinammomum loureiroi). As far as we've been able to determine, Cinnamom cassia and Cinnamomum aromaticum are two names for the same plant, just as Ceylon cinnamon may be called either Cinnamomum verum or Cinnamomum zeylonicum. After some digging, we do not believe that so-called 'Indonesian cassia' (Cinnamomum loureiroi) is the plant commonly sold as cinnamon in the US, but that it is, rather, Cinnamomum cassia.

Many websites refer to cassia as a 'cousin' to cinnamon that 'comes from a different plant.' That simply isn't true. All cinnamon, regardless of variety, comes from one of the trees in the genus Cinnamomum (which is why all their names start with Cinnamomum). There are different varieties of these trees, just as there are different varieties of apples, oaks and other more familiar tries. Some websites say that only "true" cinnamon (by that they mean Ceylon cinnamon) has therapeutic benefits. That is not true either. Some of the research has been carried out with cassia and some with Ceylon cinnamon, the distinction being more a matter of where it was done than anything else. European researchers tend to use Ceylon cinnamon because that's the most widely available variety. Researchers in the US have used both cassia and Ceylon cinnamon, while those in India and the middle east have used any one of the varieties, depending on what was available locally.

The primary difference between the varieties in terms of possible therapeutic benefits is the amount of coumarin in each. Ceylon cinnamon has the least. Saigon cinnamon has the most and cassia is somewhere in the middle. There are as many opinions on this subject as there are websites to consult. But given the lack of a consensus, our recommendation is to avoid the use of high-coumarin varieties if you're going to make cinnamon part of your daily diet.

Where taste is concerned, Ceylon cinnamon has the sweetest taste with subtle overtones of other flavors and fragrances. But it is a milder taste than the other varieties. In general, cassia is the strongest tasting variety, but can be bitter, especially when it's old. Saigon cinnamon has a rich complex taste and is often recommended by gourmet chefs. Indonesian (Dutch or Korintje) cinnamon has a distinctly spicy flavor. All the varieties except Ceylon cinnamon are dark reddish brown, while Ceylon cinnamon is a lighter reddish brown.

Under a microscope, tiny fibers can be seen around the outside of cinnamon powder particles, reflecting its source as bark from a tree. Because of this, cinnamon floats in the air very readily and is easily inhaled. Employees at New Naturals are required to wear respirators while handling cinnamon, and an air cleaner must be in operation. Even so, the whole building has a lovely odor of cinnamon whenever it's being packaged.

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Cinnamon for diabetes

A widely publicized claim for cinnamon is that it will help control blood glucose levels. Research has given variable results in humans, but quite promising results in cell studies. There are multiple possible mechanisms for an effect on blood glucose, including a direct stimulation of insulin production, an increase in insulin sensitivity and an indirect result from delayed gastric emptying.

Unfortunately, health gurus and supplement companies have used cell studies in their advertising without revealing that human trials did not consistently have the same good results. For example, one company states that cinnamon will "increase a cell's glucose metabolism up to 20-fold."[1] Other studies in humans found no discernible effect at amounts typical of daily consumption [2]. One study found that a cinnamaldehyde extract increased insulin production in rats who had been made diabetic by injecting them with streptozotocin, a common way of inducing diabetes in laboratory animals[3]. But a 95% standardized extract of cinnamaldehyde is not the same thing as sprinkling cinnamon on your breakfast cereal.

A 2015 study reported in the Journal of Intercultural Ethnopharmacy reported a significant drop in blood glucose in a small group of Iraqi citizens with poorly controlled diabetes[4]. A total patient cohort of 26 was divided into two groups: one group of 13 was given capsules containing 500 milligrams of whole cinnamon powder, and instructed to have two capsules day. Another group of 12 people received placebo capsules.

This particular trial had multiple design issues, however. The only comparison was between the initial two groups of people. The trial was not repeated with a switch in who received the placebo capsules. So there could have been confounding factors in diet, lifestyle and other elements between the two groups that would have been minimized by repeating the trial and switching which group received the placebo.

Another similar trial with Pakistani patients taking glibenclamide tested dosages of 1 gram, 3 grams and 6 grams[5]. Interestingly, the researchers did not find any increase in benefits with the larger dosages of cinnamon. This trial had a 20-day washout period, and at the end of that time, the patients who had been given the lowest amount of cinnamon during the trial had the greatest persisting degree of benefit. But again, the small number of trial participants makes it difficult to determine what other factors might have been present. Each arm of the trial consisted of only 10 patients, with 30 patients receiving a placebo. The trial was not repeated with the three cinnamon arms being switched with the 30 patients in the placebo arm.

Another factor that may have influenced both these trials is that they took place in locations where turmeric is in regular use, especially the one in Pakistan. Turmeric is known to increase insulin sensitivity and may also enhance glucose metabolism. The presence of turmeric in the diet may explain the fact that an increase in cinnamon consumption did not significantly improve blood glucose levels, since the turmeric may have established a baseline level of control that the cinnamon could not exceed by much.

A trial carried out on a US military base (Eglin AFB, Florida) with 109 patients may provide a better insight into the use of cinnamon in the United States and other developed countries. It investigated whether cinnamon would help to lower HbA1c levels[6]. This trial was a casual one, non-blinded with no placebo arm, though there was a control group of patients who continued their standard treatment without adding cinnamon. The participants were not sorted by treatment protocol, so some of them were no doubt taking oral diabetes medications and some may have been taking insulin. The principal investigator stated that the trial "… strove to replicate the conditions found in primary care, where patients often have medication changes, comorbid conditions, and dietary changes." The amount of cinnamon was 1 gram per day, given as two 500mg capsules of Cinnamomum cassia (the same cinnamon typically sold in grocery stores, and thus easily available to participants after the trial).

This trial found that participants experienced a greater drop in HbA1c levels over a period of 90 days if cinnamon was added to their current treatment. Specifically, participants in the cinnamon arm went from an average HbA1c of 8.47 to 7.64, where the control participants only dropped from an average of 8.28 to 7.91. The difference in change was only .83%. But the end point of the cinnamon arm was lower than the end point of the control arm, even though the beginning point had been higher. So this is a significant difference.

The bottom line appears to be that cinnamon may indeed be helpful with blood glucose control, in the context of a healthy diet and adequate medical treatment. We would not recommend the use of cinnamon as a substitute for proper medical care for diabetes.

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Cinnamon as an anti-inflammatory

Cinnamon's effect on inflammation is one of the more thoroughly studied and better documented benefits. Chapter 30 of the book Polyphenols in Human Health and Disease[8], gives a succinct definition of inflammation and its consequences:

The inflammatory response is a complex self-limiting process precisely regulated to prevent extensive damage to the host. When the self-limiting nature of this protective mechanism is inappropriately regulated, it results in chronic inflammation, which is associated with a number of chronic inflammatory diseases, including asthma, rheumatoid arthritis, inflammatory bowel disease, atherosclerosis, Alzheimer's disease (AD), and cancer.

Much of the laboratory research has been done with water-soluble extracts and with mice and rats, rather than with whole cinnamon and humans. Even so, the fundamental changes caused by the extracts suggest that similar effects would be observed in other organisms as well. For example, in one trial, mice were fed a water-soluble extract of cinnamon for six days before being inoculated with LPS[7]. Serum levels of TNF-a and IL-6, two inflammatory markers, were significantly reduced.

Inflammatory bowel disease is characterized by elevated inflammatory markers, increased intestinal wall thickness, tissue damage and increased mast cell activation. As the authors of a German study pointed out, patient compliance with medications prescribed for IBD is often a problem. So it would be helpful if a common food could be employed in place of the medications. An ethanolic extract of cinnamon added to the drinking water of mice suffering with colitis decreased all the inflammatory markers and resulted in decreased tissue damage in the mice fed cinnamon [10]. Tight-junction proteins play a part in protecting intestinal cell walls, and these are influenced in part by cytokines such as tumor necrosis factor and by mast cell proteases (one type of enzyme). The trial found that even though cinnamon reduced inflammatory markers, it did not adversely affect the tight-junction proteins. The number of mast cells, which play a part in inflammatory processes in the colon, was reduced, along with IBD symptoms such as rectal inflammation and stool consistency.

An Iranian study of cinnamon and ginger to reduce muscle soreness in female athletes after exercise found no decrease in the one inflammatory marker that was tested (interleukin-6). But oral cinnamon did provide a significant reduction in scale on the Likert Scale of Muscle Soreness [11]. Athletes were given either 3 grams cinnamon, 3 grams of ginger or a placebo each day for six weeks. Ginger provided a smaller but still statistically significant benefit. A 2017 study published in the Journal of the American College of Nutrition looked at the effect of cinnamon on 36 women with rheumatoid arthritis [12]. CRP, TNF-α, ESR and other markers of inflammation were tested at the beginning of the trial and at the end of the 8-week study period. All inflammatory markers except for ESR were improved, and clinical symptoms of RA had improved. Although blood pressure was not one of the study test points, the study found that diastolic blood pressures improved in the group receiving the cinnamon.

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Cinnamon for multiple sclerosis

One trial used whole cinnamon powder in an animal model of multiple sclerosis[9]. It found that cinnamon significantly reduced clinical symptoms, helped to protect the blood-brain barrier and blood-spinal cord barrier, and reduced nerve demyelination.

A review article in the Journal of Multiple Sclerosis examined a variety of benefits that cinnamon provides for multiple sclerosis [13]. Cinnamaldehyde, the primary active compound in cinnamon bark, is metabolized to cinnamic acid, and thence to sodium benzoate. Sodium benzoate (NaB) has widespread use in the food processing and cosmentic industries as a safe and effective preservative. However, NaB can also inhibit two types of brain cells involved in multiple sclerosis-astrocytes and microglia. Cinnamon also helped to protect T regulatory cells (Tregs) via its metabolism to NaB, and slowed demyelination.

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Cinnamon for Alzheimers

A 2009 study of the effect of cinnamaldehyde on tau proteins found that cinnamaldehyde not only would inhibit the formation of tau plaques, but also-in vitro, at least-could prompt them to untangle [14]. A follow up study [15] by the same authors in 2013 found that cinnamaldehyde provided this protection without interfering with tau's proper and desirable function, microtubule assembly. Epicatechin, another of cinnamon's active compounds, can also sequester toxic products produced by oxidation, and reduce their burden in body and brain.

The recent discovery that Alzheimers may be caused by an infectious prion suggests that cinnamon may also have a role in combating prions, though no research has been published so far.

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Cinnamon and cannabinoids

Like black pepper, cloves and an extensive list of other herbs and spices, cinnamon contains caryophyllene, which binds to the CB2 receptors of our endocannabinoid system. The therapeutic benefit of caryophyllene has not been widely researched and is still largely unknown, but has been proposed as a possible substitute for cannabinoids derived from marijuana.

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Cinnamon in the garden

Cinnamon and its extracts have wide usage in the cosmetic and fragrance industries. Cinnamon-scented candles and other forms of aromatherapy are popular, for example. Cinnamon essential oil is marketed by at least one company with claims of beneficial effects for skin conditions. But did you know that cinnamon is also a very effective fungicide? Cinnamaldehyde is a registered fungicide effective against Verticillium, Rhizoctonia, Pythium and others. To use it in the garden, add 4 tablespoons cinnamon powder to a half gallon of tap water. Let it steep for a few hours or overnight to create an aqueous solution of cinnamaldehyde. Strain well to use in a sprayer. The residue left from straining the mixture can be used on the soil as well to kill fungi. Cinnamon oil has also been touted as a fungicide, but it's easy to use too strong a concentration and damage plants. The aqueous solution is much less likely to do that, and is still effective.

Another use for cinnamon in the garden is as a rooting agent. Dipping or otherwise applying cinnamon powder when you root cuttings helps to prevent fungal diseases that may kill the cutting, and also appears to help promote rooting itself.

Glossary

95% standardized extract: a botanical extract that contains a single constituent from the plant (cinnamaldehyde from cinnamon, for example) in a 95% concentrate, used primarily for research into that constituent's effects

Astrocytes: star-shaped cells in the brain, that help to protect the blood-brain barrier. They also participate in establishing circadian rhythms, transporting neurotransmitters such as serotonin, epinephrine and dopamine, and providing nutrients to neurons

Caryophyllene: a sesquiterpene (a class of hydrocarbons in a specific ring formation) found in many plant oils, such as cinnamon, rosemary, black pepper, cloves and, incidentally, Cannabis sativa.

CRP: C-reactive protein, a protein whose value is elevated when infection or trauma causes inflammation. It's often performed as part of a complete blood panel, but is useful primarily as a comparison with known values for the individual. Elevation from a previous test for the same individual would suggest increased inflammation, but absolute values vary substantially from one individual to another.

Coumarin: a compound found in varying amounts in different varieties of cinnamon. In large amounts or extended use, coumarin may cause liver damage. Coumadin, a prescription anticoagulant, is derived from coumarin, but coumarin itself does not affect clotting.

Demyelination: damage to the myelin sheath surrounding neurons, which adversely affects signaling in the brain and nervous system.

Diastolic blood pressure: the blood pressure during the 'relaxed' phase of the heart's rhythm. Systolic blood pressure indicates the pressure during the active contracting phase. Heart muscle contracts to force blood into the arteries, and then relaxes to allow blood returning from the veins to fill the heart again.

Endocannabinoid system: the system of endocannabinoid compounds and their receptors that regulate large parts of mammalian nervous systems, as well as physiological processes such as appetite, pain sensation, memory and other cognitive functions.

ESR: erythrocyte sedimentation rate, a non-specific test for inflammation. Sometimes called the SED rate, it's determined by the rate at which red blood cells drift to the bottom of a specialized kind of test tube. When inflammation is present, red blood cells tend to clump together in clusters that fall faster than individual cells.

Ethanolic extract: An extract made by dissolving a compound in ethyl alcohol.

HbA1c: (glycated hemoglobin) is a measure of the amount of glucose that has bonded with hemoglobin in red blood cells. Higher blood sugar levels mean that more hemoglobin will be 'glycated.' Since red blood cells have a lifespan of 2-3 months, the HbA1c test gives a reasonably accurate idea of what average blood glucose levels have been over that time frame.

Il-6: interleukin-6, a protein produced in response to infections and tissue injuries, is also an indicator of chronic inflammation when its regulatory process becomes dysregulated.

In vitro: processes that take place in test tubes or culture dishes rather than in a living body. Often the first step in research that may lead to in vivo (in a living body) work later.

LPS: Lipopolysaccharide, a compound from bacteria that stimulates a strong immune response and is often used to determine the anti-inflammatory benefit of a compound being tested

Mast cells: a type of 'granulated' cell that contains granules of histamine and heparin. Mast cells play a large part in immune responses, especially reactions to allergens.

Microglia: small cells in the brain and spinal cord that constitute a primary immune defense system for the central nervous system

Microtubules: polymers that provide structure to essential parts of our cells; tau proteins participate in their formation.

Prion: misfolded proteins that can 'infect' normal proteins by converting them to the same misfolded configuration, with fatal results. Scrapie in sheep, bovine spongiform encephalopathy in cattle (often called 'mad cow disease') and Creuzfeld-Jacob Disease in humans are caused by prions. Recently it was confirmed that Alzheimers Disease is similarly caused by an infectious prion.

Tau proteins: the proteins that form tangled plaques of fibers found in the brains of Alzheimers patients

Tight-junction proteins: Proteins which hold cells together, and in doing so, present a barrier that prevents compounds from passing between the cells. Defects in such barriers may allow nutrients to leak from the intestines (so-called 'leaky gut syndrome') into the surrounding spaces rather than being properly diffused through the cells.

TNF-a: Tumor Necrosis Factor-alpha. TNF is an important signalling protein in immune system processes.

Reference

1.Isolation and Characterization of Polyphenol Type-A Polymers from Cinnamon with Insulin-like Biological Activity, Journal of Agricultural and Food Chemistry 2004 / 01 Vol. 52; Iss. 1

2. The Effect of Cinnamon on Glucose of Type II Diabetes Patients, Journal of Traditional and Complementary Medicine, July-Sept 2013, pp 171-174

3. Cinnamaldehyde-A potential antidiabetic agent, Phytomedicine, January 10, 2007, pp 15-22

4. Anti-diabetic and antioxidant effect of cinnamon in poorly controlled type-2 diabetic Iraqi patients: A randomized, placebo-controlled clinical trial, Journal of Intercultural Ethnopharmacy, March-April 2016, pp 108-113

5. Cinnamon Improves Glucose and Lipids of People With Type 2 Diabetes, Diabetes Care, December 2013

6. Effectiveness of Cinnamon for Lowering Hemoglobin A1C in Patients with Type 2 Diabetes: A Randomized, Controlled Trial, Journal of the American Board of Family Medicine, September 2009, pp 507-512

7. , BioMed Central, Complementary and Alternative Medicine, November 2012

8. Polyphenols in Human Health and Disease, Volume 1, Chapter 30, pp 409-425

9. Cinnamon ameliorates experimental allergic encephalomyelitis in mice via regulatory T cells: implications for multiple sclerosis therapy, PLOS ONE, January 2015

10. Cinnamon extract reduces symptoms, inflammatory mediators and mast cell markers in murine IL-10?/? colitis, Journal of Nutritional Biochemistry, Volume 30, April 2016, Pages 85-92

11. Influence of ginger and cinnamon intake on inflammation and muscle soreness endued by exercise in Iranian female athletes, International Journal of Preventive Medicine, April 2013

12. Cinnamon Consumption Improves Clinical Symptoms and Inflammatory Markers in Women With Rheumatoid Arthritis, Journal of the American College of Nutrition, May 2018

13. Prospects of Cinnamon in Multiple Sclerosis, Journal of Multiple Sclerosis, Sept 2015

14. Cinnamon extract inhibits tau aggregation associated with Alzheimer's disease in vitro, Journal of Alzheimer's Disease, 2009.

15. Interaction of Cinnamaldehyde and Epicatechin with Tau: Implications of Beneficial Effects in Modulating Alzheimer's Disease Pathogenesis, Journal of Alzheimer's Disease, Vol. 35 Issue 1, June 2013

16. NON-CANNABIS THERAPY - Cannabinoid Therapy Without Using Cannabis: Direct Effects™ Topical β-Caryophyllene, Drug Development and Delivery, May 2017

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