Cinnamon is a versatile and aromatic spice rich in polyphenolic compounds that act as protective antioxidants. Just smelling cinnamon increases a person's cognitive ability and actually functioned as a kind of a "brain boost". It comes from the interior bark of evergreen trees that are native to Asia (i.e., China, Ceylon, Indonesia, and Vietnam).
There are two main commercial types of cinnamon:
- Ceylon cinnamon
- Mainly from Ceylon or Sri Lanka
- Cassia cinnamon
- Mainly cultivated in Vietnam, China, and Indonesia
Cassia cinnamon contains high levels (up to 1 %) of coumarin. In contrast, Ceylon cinnamon contains much less coumarin. Coumarin is known to cause liver and kidney damage in rats, mice and probably humans. Therefore, European health agencies have warned against consuming high amounts of Cassia for long periods[2,8].
In one recent study, cinnamon was shown to reduce the oxidative stress and impaired fasting glucose (two risk factors associated with cardiovascular disease and diabetes) in overweight and obese adults.
- In one laboratory study, cinnamon and cloves turned out to be the nicest spices for preventing fatty acid oxidation.
- Other research suggests that cinnamon and cardamom may act by waking up antioxidant enzymes and sending them off to work.
- Fascinating new research reveals that people with type 2 diabetes who consumed 1 to 2 teaspoons of cinnamon daily had lower levels of blood sugar, triglycerides, LDL cholesterol, and total cholesterol.
- Cinnamon boosts the ability of insulin to metabolize glucose and carry it into cells for energy production
- Just one-quarter to one-half teaspoon can result in a 20% drop in blood sugar
- Cinnamon contains coumarin, which in larger amounts can have a blood-thinning effect.
- A 2007 study in the American Journal of Clinical Nutrition showed that adding a teaspoon of cinnamon to rice pudding blunted the usual high-blood-sugar response following dessert.
- Experiments at the USDA's Human Nutrition Research Center revealed that an ingredient in cinnamon called methylhydroxychalcone polymer (MHCP) mimics insulin and increases the sensitivity of the receptors on the cells to the action of insulin.[9,10]
- The researchers found these beneficial metabolic effects with as little as 1/2 teaspoon of cinnamon per day.
- In test tubes, MHCP increased insulin's processing of blood sugar by 2,000%, or 20-fold.
- As an added nutritional perk, 2 teaspoons of cinnamon contain 57 mg of calcium.
- At least three new studies have shown that it can also help alleviate inflammation by controlling a protein that triggers the inflammatory response.
- Cinnamon increases circulation, especially in arthritic joints.
- Cinnamon may prevent or get rid of tau in human brain cells
- Dr. Richard Anderson at the U.S. Department of Agriculture has shown that cinnamon may stop the genesis of Alzheimere's:
- In brain cell studies, a water-soluble cinnamon extract blocked the formation of "tau filaments," which help to initiate Alzheimer's
- The cinnamon extract, when incubated in test tubes with tau tangles, quickly destroyed them
- Cinnamon can function as an antibacterial (from the essential oil)
- It can stop the growth of bacteria (i.e., E. coli) as well as fungi, including the common yeast Candida.
- Spices such as cinnamon, garlic, sage, and clove may inhibit bacterial growth and help keep cooked food from spoiling.
- Cinnamon is now being tested for its ability to knock out Helicobacter pylori, the bacteria that cause most stomach ulcers. Stay tuned for more on that research front.
- In one study, high doses of cinnamon bark oil stopped mold from growing in laboratory petri dishes.
Cinnamon is well tolerated. However, precautions should be taken for:
- Liver problem
- To be safe, caution is advised for anyone with liver problems.
- The U.S. National Library of Medicine warns that too much cassia cinnamon taken along with medications that could cause possible liver damage might increase the chance of liver damage. 
- Due to its blood-thinning effects, cinnamon in quantities greater than use as a spice should end at least one week prior to surgery.
- Medicinal doses are not recommended during pregnancy
- Close monitoring of blood sugar levels in diabetics is warranted to avoid unsafe lowering of blood sugar.
Try to buy organically grown cinnamon, as it is less likely to have been irradiated. We know that irradiating cinnamon may lead to a decrease in its vitamin C and carotenoid content. You may also want to take it in capsule form, so that it bypasses the saliva in the mouth on its way to the stomach. Saliva can actually reduce the beneficial effects of this spice. Finally, cinnamon contains both water-soluble and fat-soluble compounds. Fat-soluble compounds may accumulate in the body if ingested over a long period.