Cinnamon is a tropical medium-sized, bushy evergreen tree and is one of the world’s oldest spices. Approximately 250 species have been identified among the cinnamon genus, with trees being scattered all over the world. As a spice, cinnamon is available in powder form or whole and as pieces of bark. People can also use cinnamon essential oil and supplements.
The bark of various cinnamon species is one of the most important and popular spices used worldwide not only for cooking but also in traditional and modern medicines.
Cinnamon is also used in the aroma and essence industries due to its fragrance, which can be incorporated into different varieties of foodstuffs, perfumes, and medicinal products.
The major constituents of cinnamon are cinnamaldehyde and trans-cinnamaldehyde (Cin), contributing to the fragrance and also to the various biological activities observed with cinnamon such as antidiabetic, anti-inflammatory, antimicrobial, antioxidant, antitumor, cardiovascular, cholesterol-lowering, and immunomodulatory.
Cinnamon may act as an insulin mimetic, to potentiate insulin activity or to stimulate cellular glucose metabolism. It has strong hypoglycemic properties. A study comparing the insulin-potentiating effects of many spices revealed that the aqueous extract of cinnamon was 20-fold higher than the other spices.
Cinnamon showed an antidiabetic effect through enhancing the translocation of glucose transporter type 4 (GLUT4) in the adipose tissues and muscle and it causes upregulation of uncoupling protein-1 (UCP-1). Phenolic compounds and volatile oils, mainly cinnamaldehyde in cinnamon play a vital role in improvement of insulin signaling.
Several studies have revealed that cinnamon lower not only blood glucose but also cholesterol levels hence plays a key role in the advancement of human health. It has been reported that the administration of cinnamon at 1 and 3 g doses per day caused a reduction in serum glucose, triglyceride, total cholesterol, and LDL cholesterol levels in humans.
The available data suggests that despite the safety of cinnamon use as a spice or flavoring agents, its use may be associated with significant adverse effects in medicinal uses with larger doses or longer duration of use. The most frequent adverse affects were gastrointestinal disorders and allergic reactions which were self-limiting in the majority of cases.
The typical recommended dose is 1 to 4 grams daily of ground according to New York University. Cinnamon oil is generally used at a dose of 0.05 to 0.2 g daily. It is not recommended during pregnancy because it can induce uterine contractions and in some cases even cause premature labor.
References
S. Chilton, “Encyclopedia of common natural ingredients used in food, drugs, and cosmetics,” American Scientist, vol. 85, issue 1, pp. 83, 1997.
E. Ernst “Herbal medicinal products during pregnancy: are they safe?,” BJOG: An International Journal of Obstetrics & Gynaecology, vol. 109, issue 3, pp. 227-235, 2002.
Charles, D.J. (2012). Cinnamon. In: Antioxidant Properties of Spices, Herbs and Other Sources. Springer, New York, NY. https://doi.org/10.1007/978-1-4614-4310-0_19