In classical times, four types of cinnamon were distinguished (and often confused):

• Cassia (Hebrew qəṣi`â), the bark of Cinnamomum iners from Arabia and Ethiopia
• True Cinnamon (Hebrew qinnamon), the bark of Cinnamomum zeylanicum from Sri Lanka
• Malabathrum or Malobathrum (from Sanskrit तमालपत्रम्, tamālapattram, literally “dark-tree leaves”), Cinnamomum malabathrum from the north of India
• Serichatum, Cinnamomum aromaticum from Seres, that is, China.

Cinnamon (Cinnamomum verum, synonym C. zeylanicum) is a small evergreen tree belonging to the family Lauraceae, native to Sri Lanka,^[1] or the spice obtained from the tree’s bark. It is often confused with other, similar species and the spices derived from them, such as Cassia and Cinnamomum burmannii, which are also often called cinnamon.

Dried cassia bark

Cinnamomum burmannii

From Wikipedia, the free encyclopedia

Cinnamomum burmannii
Young Indonesian Cassia tree, Indonesia
Scientific classification
Kingdom:	Plantae
(unranked):	Angiosperms
(unranked):	Magnoliids
Order:	Laurales
Family:	Lauraceae
Genus:	Cinnamomum
Species:	C. burmannii
Binomial name
Cinnamomum burmannii

Cinnamomum burmannii, also known as Indonesian Cinnamon, Padang Cassia, or Korintje, is one of several plants in the genus Cinnamomum whose bark are sold as the spice cinnamon^[1], although, in many countries, only true cinnamon can be sold under that name^{[citation needed]}. The spice is the least expensive of the three common forms of cinnamon as it has the lowest essential oil content. The most common and cheapest type of cinnamon in the US is made from powdered Cinnamomum burmannii. As a result of the low oil content, Cinnamomum burmannii may have less of the mildly toxic substance coumarin than does C. cassia^[2]. It is also sold as neat thick quills which are made of one layer.^[3].

Cassia (called ròu gùi; 肉桂 in Chinese) is used in traditional Chinese medicine, where it is considered one of the 50 fundamental herbs.^[7]

In 2006, a study reported no statistically significant additional benefit when cinnamon cassia powder was given to type 2 diabetes patients who were already being treated with metformin.^[8] A systematic review of research indicates that cinnamon may reduce fasting blood sugar, but does not have an effect on hemoglobin A1C, a biological marker of long-term diabetes.^[9]

Chemist Richard Anderson says that his research has shown that most, if not all, of cinnamon’s antidiabetic effect is in its water-soluble fraction, not the oil (the ground cinnamon spice itself should be ingested for benefit, not the oil or a water extraction). In fact, some cinnamon oil-entrained compounds could prove toxic in high concentrations. Cassia’s effects on enhancing insulin sensitivity appear to be mediated by polyphenols.^[10] Despite these findings, cassia should not be used in place of anti-diabetic drugs, unless blood glucose levels are closely monitored, and its use is combined with a strictly controlled diet and exercise program.

Due to a toxic component called coumarin, European health agencies have warned against consuming high amounts of cassia.^[11]Other possible toxins founds in the bark/powder are cinnamaldehyde and styrene^[12].

Cinnamaldehyde is the organic compound that gives cinnamon its flavor and odor.^[1] This pale yellow viscous liquid occurs naturally in the bark of cinnamon trees and other species of the genus Cinnamomum. The essential oil of cinnamon bark is about 90% cinnamaldehyde.

Styrene, also known as vinyl benzene, is an organic compound with the chemical formula C₆H₅CH=CH₂. This cyclic hydrocarbon is a colorless oily liquid that evaporates easily and has a sweet smell, although high concentrations confer a less pleasant odor. Styrene is the precursor to polystyrene and several copolymers. Approximately 15 billion lt are produced annually.^[1]