Cinnamon is a spice obtained from the inner bark of several tree species from the genus Cinnamomum. It is native to Sri Lanka, but is also found throughout India, Bangladesh, Java, Sumatra, West Indies, Brazil, Egypt and Vietnam.
Cinnamon sticks are made from the bark of the tree and are rolled naturally into a quill shape when the bark is sun-dried. The oil is traditionally prepared by roughly pounding the bark, macerating it in seawater, and then quickly distilling the resulting liquid. It is of a golden-yellow colour with the characteristic odour of cinnamon and a very hot, aromatic taste and has been used for thousands of years as a culinary spice in many cultures.
Cinnamon’s history as a medicinal plant goes back as far as the ancient Egyptians and Chinese. Three of the main biological constituents of the essential oils obtained from cinnamon are trans-cinnamaldehyde, eugenol and linalool, which represent 82.5% of the total composition.
Other health giving constituents of cinnamon are oligopolymeric procyanidins, cinnamic acid, phenolic acids, pentacyclic diterpenes, cinnzeylanol and its acetyl derivative cinnzeylanine and the sugars mannitol, L-arabino-D-xylanose, L-arabinose, D-xylose, α-D-glucan as well as mucilage polysaccharides. Each 100 grams contains vitamin A: 260 IU, thiamine: 0.02 mg, riboflavin: 0.14 mg, niacin: 1.3 mg, ascorbic acid: 28 mg, Ca: 1.228 mg, P: 61 mg, Fe: 38 mg, Mg: 56 mg, Na: 26 mg, K: 500 mg, Zn: 2 mg.
Cinnamon has become a natural product of interest because it has been observed to provide health benefits such as the ability to lower serum lipids and blood glucose. Several studies have examined the effects of cinnamon on glucose, insulin, and lipid metabolism associated with metabolic diseases such as diabetes mellitus. It has been suggested that the mechanism by which cinnamon expresses its effect on blood glucose can be attributed to its active component cinnamaldehyde. The insulinotropic effects of cinnamaldehyde have been preliminarily investigated and are thought to be responsible for the following:
In animal studies, cinnamon extracts have been shown to increase the expression of peroxisome proliferator-activated receptors (PPARs), which are transcriptional factors involved in the regulation of insulin resistance and the formation of fat cells, resulting in improved lipid and glucose metabolism.
A meta-analysis done for 10 randomized controlled trials including 543 patients has established that cinnamon, when taken in a dose of 120 mg/day to 6 g/day for approximately 4 months leads to a statistical decrease in levels of fasting plasma glucose along with an improvement in the lipid profile.
One of the main reason’s cinnamon has been included in Healthy Ageing Essentials is because it has been seen to have an insulin mimetic and insulin sensitizing action. Cinnamon plays a significant role in the function of cellular signalling proteins and enhancement of expression of insulin sensitive glucose transporters which limits the progress of insulin resistance. This has downstream effects on the reduction of IGF-1 in the liver and the resulting inhibition of mTOR gene expression.
A recent meta-analysis, and a systematic review, on the effects of cinnamon on diabetes demonstrate numerous beneficial effects both in vitro and in vivo. The beneficial effects of cinnamon in vivo included:
In vitro cinnamon has demonstrated a potential for:
Cinnamtannin B1 was identified as the potential active compound responsible for these effects in the lists above.