Cinnamon and health

The link between cinnamon and health has been recognised for a long time in traditional cultures. Cinnamon is thought to be antimicrobial, antiinflammatory (1, 2, 3, 4), antifungal (1, 2), antioxidant, antidiabetic (1, 2, 4), antimycotic (1) and anticancer (1, 2, 5). Thus, people have been using the spice for multiple purposes, including bad breath (1, 2), colon health (1, 2, 3), coagulation (1) and food preservation (4).

What is cinnamon?

Cinnamon is a spice obtained from the bark of trees in the Cinnamomum genus (4, 7). Only some of the approximately 250 species in the genus are used as a spice (1, 6, 7).

Cinnamomum verum, a.k.a. C. zeylanicum, true cinnamon or Ceylon cinnamon, hails mainly from Sri Lanka (2, 3, 6, 7). Another well-known species is Chinese cassia cinnamon, a.k.a. Cinnamomum cassia (6, 7). The spice is sold as sticks of bark (i.e. quills), ground powder (6, 7) and extracts (6).

Cinnamon composition

The main components in cinnamon are volatile oils such as cinnamaldehyde (responsible for the taste and aroma of the spice), cinnamate, cinnamic acid, trans-cinnamaldehyde, cinnamyl acetate, eugenol and camphor (1, 2, 3, 4, 6, 7). Other compounds include polyphenols, trace elements and coumarin (4, 6).

Cinnamon and health

The health benefits of cinnamon have mostly been investigated in animal and in vitro (i.e. cell culture) studies. There are some human studies which, as a whole, do not paint a conclusive picture.

Diabetes

This is one of main areas of research on the topic. Several studies have shown cinnamon extracts to lower blood glucose, cholesterol levels and other markers of glucose metabolism dysregulation (1, 2, 3, 4, 7).

The mechanisms identified through animal and in vitro studies include upregulation of glucose uptake (2, 3) due to increase in activity and number of the insulin receptors (3, 4, 7), increase of glycogen synthesis (2, 3, 4) and reduction of glucose absorption in the small intestine (2, 3). Some compounds in cinnamon have been found to have an activity similar to insulin. Human studies have shown cinnamon to stimulate the production of insulin and decrease insulin resistance (2, 4). Cinnamon may also help control diabetes by regulating adipogenesis (generation of fat cells) and inflammation (4).

On the flip side, systematic reviews of studies looking at markers of diabetes such as fasting blood glucose and haemoglobin A1c (HbA1c, which indicates average blood sugar in the last 3 months) have found inconclusive results. Moreover, some of the positive results were modest and/or clinically insignificant. Potential reasons include variability in subjects and product used for treatment, as well as concurrent standard of care therapy (i.e. medications) (6, 7).

Oxidative stress

Some studies have reported that cinnamon extracts protect from free radical damage and exhibit antioxidant activity. This activity could potentially protect against metabolic and age-related diseases (1, 2, 3, 4).

Inflammation

Several flavonoids isolated from cinnamon have been shown to have anti-inflammatory activity. Research suggests that some species could be used for the treatment or prevention of conditions with an inflammatory component (1, 2).

Neurological disorders

Some components and metabolites of cinnamon might protect the nervous system against ischaemic and oxidative damage. A cinnamon extract has also been shown to reduce tau protein aggregation and filament formation, which occur in Alzheimer’s disease (1).

Microbes

Some research indicates that the essential oils in cinnamon have antimicrobial activity (1) against many bacteria, fungi and the human rota-virus (3). In particular, chewing gum containing bioactive compounds from cinnamon has shown to reduce certain bacteria in saliva (3).

Cancer

Cinnamon extracts could be used in cancer prevention as they act against angiogenesis (formation of new blood vessels) (1), inhibit cancer-related cytokines (1), inhibit tumour cell growth (1, 5) and proliferation (5). They also have a cytotoxic effect on certain cancer cells (3), induce tumor apoptosis (programmed cell death) (1, 5) and mitochondrial dysfunction (5).

Cardiovascular health

The effects of cinnamon components and extracts on the cardiovascular system include improving endothelial (internal tissue layer) function (1) and lowering blood pressure (1, 2, 4).

Blood lipids

Human studies have found cinnamon to be effective in lowering triglycerides, total cholesterol and LDL cholesterol (1, 2, 4).

Advanced glycation end products (AGEs)

Phenolic compounds in cinnamon may prevent the formation of AGEs (1), which are compounds that can cause accelerated ageing and degenerative conditions.

Skin and bones

Cinnamon might play a role in collagen synthesis in skin and prevent bone breakdown (3).

Cons

Negative effects of cinnamon consumption seem to be rare and include irritation, contact allergies (6, 7) and nausea (7).

In addition, the compound coumarin, which is higher in Cinnamon cassia than Ceylon Cinnamon, is toxic to the liver(7).

Form and doses

The form of cinnamon administered in studies vary from powder to capsules and extracts (6, 7). Doses vary from 500 mg to 6 g and all doses seem to be effective with no dose-response relationship when measuring glycaemic effects (7).

Recommendations

If you don’t have any side effects, daily intake of cinnamon is not likely to be harmful. Given that some evidence exists of a positive link between cinnamon and health, it might be beneficial to consume it on a regular basis. Just don’t assume this is the superfood that will cure all your ailments, nor a replacement for prescribed medications.

Cinnamon can be enjoyed in multiple ways, for example:

• Sprinkled on yoghurt, fruit (e.g. papaya, banana), cereal, porridge, pudding or custard-type desserts, ice cream
• As an ingredient in sweet foods such as smoothies, cookies, muffins, cakes, etc.
• As an ingredient in savoury foods such as stews, tagines, curries, etc.
• As an infusion, just steep cinnamon sticks in hot or warm water and let cool down.

Please note that many of the foods mentioned above are discretionary choices and should not be consumed often.

References

1. Rao PV, Gan SH. Cinnamon: A Multifaceted Medicinal Plant. Evidence-Based Complementary and Alternative Medicine. 2014;2014:1-12.
2. Mollazadeh H, Hosseinzadeh H. Cinnamon effects on metabolic syndrome: a review based on its mechanisms. Iranian Journal of Basic Medical Sciences. 2016;19(12):1258-70.
3. Ranasinghe P, Pigera S, Premakumara GAS, Galappaththy P, Constantine GR, Katulanda P. Medicinal properties of ‘true’ cinnamon (Cinnamomum zeylanicum): a systematic review. BMC Complementary and Alternative Medicine. 2013;13:275-.
4. Rafehi H, Ververis K, Karagiannis TC. Controversies surrounding the clinical potential of cinnamon for the management of diabetes. Diabetes, obesity & metabolism. 2012;14(6):493-9.
5. Dutta A, Chakraborty A. Cinnamon in Anticancer Armamentarium: A Molecular Approach. Journal of Toxicology. 2018;2018.
6. Costello RB, Dwyer JT, Saldanha L, Bailey RL, Merkel J, Wambogo E. Do Cinnamon Supplements Have a Role in Glycemic Control in Type 2 Diabetes? A Narrative Review. Journal of the Academy of Nutrition and Dietetics. 2016;116(11):1794-802.
7. Medagama AB. The glycaemic outcomes of Cinnamon, a review of the experimental evidence and clinical trials. Nutr J. 2015;14:108.

[Photo by Uriel Soberanes on Unsplash]

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