The Critical Difference: Cassia vs. Ceylon
Not all cinnamon is created equal. The two primary types sold are Cassia and Ceylon, and their differing chemical compositions are central to understanding the risks of overconsumption.
Cassia Cinnamon: The Common & Risky Variety
Most cinnamon sold in North American supermarkets is Cassia cinnamon, which comes from the Cinnamomum cassia tree. It is cheaper and has a stronger, more pungent flavor. However, it contains high levels of coumarin, a naturally occurring compound known to be toxic to the liver in large doses. Regular, heavy consumption of Cassia is the primary cause for concern regarding cinnamon toxicity.
Ceylon Cinnamon: The Safer 'True' Cinnamon
Ceylon cinnamon, or "true cinnamon," comes from the Cinnamomum verum tree, native to Sri Lanka. It has a lighter, sweeter, and more delicate flavor. Crucially, Ceylon cinnamon contains only trace amounts of coumarin, making it significantly safer for regular, long-term use, especially in larger quantities.
Liver Damage from High Coumarin Intake
The most serious risk associated with consuming too much Cassia cinnamon is liver damage. Coumarin, the compound responsible for this toxicity, can be especially harmful to individuals with pre-existing liver conditions. Animal studies have shown that high doses of coumarin over a prolonged period can cause liver inflammation or more serious damage. The European Food Safety Authority has established a tolerable daily intake (TDI) for coumarin at 0.1 mg per kg of body weight, a limit easily surpassed with regular, high-dose consumption of Cassia cinnamon or supplements.
The Risk of Low Blood Sugar (Hypoglycemia)
Cinnamon is well-known for its potential to lower blood sugar levels and improve insulin sensitivity. While this can be beneficial for managing blood glucose, consuming large amounts, particularly in concentrated supplement form, can cause blood sugar to drop too low.
Who is at risk?
This risk is especially relevant for people with diabetes who are already taking medication to control their blood sugar. The combined effect of medication and excessive cinnamon could lead to hypoglycemia, characterized by symptoms such as dizziness, fatigue, and faintness. It is essential for diabetic individuals to monitor blood sugar closely and consult a doctor before adding significant amounts of cinnamon to their diet.
Allergic Reactions and Mouth Sores
Some individuals may experience an allergic reaction to cinnamon, often due to the compound cinnamaldehyde. Excessive consumption can trigger a condition called cinnamon stomatitis, which causes painful mouth sores or ulcers. Other symptoms can include burning, itching, or swelling of the lips and tongue. While not life-threatening, these allergic responses can be quite uncomfortable and are a clear signal to reduce intake.
Dangerous Interactions with Medications
For those on certain prescription drugs, over-consuming cinnamon can pose a serious health risk through drug interactions. Potential interactions include:
- Blood Thinners: Cassia cinnamon's high coumarin content has mild blood-thinning properties. When combined with prescription anticoagulants like warfarin, this can significantly increase the risk of bleeding.
- Diabetes Medication: As mentioned, cinnamon can enhance the blood sugar-lowering effect of medications like insulin and metformin, potentially leading to hypoglycemia.
- Liver-Affecting Drugs: The coumarin in Cassia can interact with medications metabolized by the liver, such as acetaminophen and statins, increasing the risk of liver damage.
Respiratory Dangers from Inhaling Dry Cinnamon
A well-known, albeit less common, danger comes from the inhalation of dry, ground cinnamon powder. The viral internet "cinnamon challenge" highlighted this risk, where participants attempted to consume a tablespoon of dry cinnamon in one minute. The fine powder can easily be inhaled, irritating the throat and lungs. Since the lungs cannot break down the spice's fibers, it can accumulate, leading to inflammation and potentially aspiration pneumonia, which can cause permanent lung scarring. This is particularly dangerous for individuals with asthma or other respiratory conditions.
Other Gastrointestinal Side Effects
Beyond liver issues, excessive cinnamon can irritate the gastrointestinal tract, leading to a variety of uncomfortable symptoms. Some people may experience a burning sensation in the stomach, upset stomach, or heartburn. Long-term irritation could potentially contribute to more serious digestive problems.
Cassia vs. Ceylon: A Comparison Table
| Aspect | Cassia Cinnamon | Ceylon Cinnamon (True Cinnamon) |
|---|---|---|
| Coumarin Content | High | Low (trace amounts) |
| Toxicity Risk | Higher risk, especially to the liver with excessive intake | Very low risk for toxicity due to low coumarin |
| Flavor Profile | Strong, pungent, and spicy | Mild, delicate, and subtly sweet |
| Appearance | Thick, rough, and single-rolled bark | Thin, layered, and crumbly bark |
| Availability | Widely available and cheaper in most supermarkets | Less common and more expensive, found in specialty stores |
| Recommended Use | Moderate, occasional use due to coumarin levels | Safer for regular, daily consumption |
Conclusion
While cinnamon offers several health benefits when consumed in moderation, excessive intake, particularly of the common Cassia variety, can lead to serious side effects. The primary risks stem from the high concentration of coumarin in Cassia, which can cause liver damage, interact with medications, and dangerously lower blood sugar. Allergic reactions and respiratory issues from inhalation are also potential concerns. To mitigate these risks, consumers should be mindful of the type of cinnamon they are using and the quantity they are consuming. For those who use cinnamon frequently or in large amounts, switching to Ceylon cinnamon is a safer alternative due to its negligible coumarin content. As with any dietary change, consulting a healthcare provider is recommended, especially for those on medication or with underlying health conditions. For more information, you can research dietary guidelines and supplement safety from reputable sources like the National Center for Complementary and Integrative Health.
