Cassia (Cinnamomum aromaticum, synonym C. cassia) is an evergreen tree native to southern China and mainland Southeast Asia west to Myanmar. Like its close relative, Cinnamon (Cinnamomum zeylanicum, also known as "true cinnamon" or "Ceylon cinnamon"), it is used primarily for its aromatic bark, which is used as a spice. The Cassia tree grows to 10-15 m tall, with greyish bark, and hard elongated leaves 10-15 cm long, that have a decidedly reddish colour when young. Most of the spice sold as cinnamon in the United States and Canada (where true cinnamon is still generally unknown) is actually cassia. In some cases, cassia is labeled "Indonesian cinnamon" to distinguish it from the more expensive true cinnamon (Cinnamomum zeylanicum), which is the preferred form of the spice used in Mexico and Europe. A 2003 study published in the DiabetesCare journal followed Type 2 diabetics ingesting 1, 3 or 6 grams of cassia daily. Those taking 6 grams shows changes after 20 days, and those taking lesser doses showed changes after 40 days. Regardless of the amount of cassia taken, they reduced their mean fasting serum glucose levels 18â€“29%, their triglyceride levels 23â€“30%, their LDL cholesterol 7â€“27%, and their total cholesterol 12â€“26%, over others taking placebos. The effects, which may even be produced by brewing a tea from cassia bark, may also be beneficial for non-diabetics to prevent and control elevated glucose and blood lipid levels. Cassia's effects on enhancing insulin sensitivity appear to be mediated by polyphenols . 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. There is also much anecdotal evidence that consumption of cassia has a strong effect in lowering blood pressure, making it potentially useful to those suffering from hypertension. The USDA has three ongoing studies that are monitoring the blood pressure effect. There is concern that there is as yet no knowledge about the potential for toxic buildup of the fat-soluble components in cassia, as anything fat-soluble could potentially be subject to toxic buildup. However, people have been using the spice as a seasoning safely for thousands of years. There are no concluded long term clinical studies on the use of cassia for health reasons.