Cinnamon is a widely loved spice, prized for its warm aroma, flavour, and versatility in both sweet and savoury dishes. Often added to cereals, baked goods, teas, and smoothies, it is considered a natural way to enhance taste and even support health. However, excessive consumption can pose serious health risks, especially to the liver, due to a compound called coumarin found in certain types of cinnamon. High intake can lead to liver toxicity over time, particularly in those with pre-existing liver conditions. Being aware of the type and amount of cinnamon consumed is essential for safe, healthy use.







Coumarin: The compound that makes cinnamon harmful for the liver

The main concern with cinnamon is coumarin, a naturally occurring compound present in some types of the spice. Coumarin can be hepatotoxic in high doses, meaning it can cause liver damage over time. Regular intake of cinnamon high in coumarin can overload the liver’s detoxification system, leading to liver inflammation, elevated liver enzymes, and, in extreme cases, liver failure. According to a study published in
Food and Chemical Toxicology, heavy consumption of cassia cinnamon can result in coumarin exposure levels high enough to cause liver toxicity in sensitive individuals, underscoring the importance of monitoring cinnamon intake.



Coumarin content varies depending on the type of cinnamon. Cassia cinnamon, the variety most widely available in supermarkets, contains high levels of coumarin, sometimes enough that just a teaspoon per day exceeds the safe daily limit recommended by the
European Food Safety Authority (EFSA). Conversely, Ceylon cinnamon, also called “true cinnamon,” contains very low levels of coumarin and is much safer for regular consumption.







Who is at higher risk

People with pre-existing liver conditions, older adults, or those taking medicines that affect liver function are particularly vulnerable when consuming cinnamon high in coumarin. Their livers may already be compromised, making it harder to process and detoxify additional compounds.







Other health risks of excessive cinnamon consumption

While liver damage is the most serious concern, consuming too much cinnamon can also lead to other health issues. High levels of coumarin may interfere with blood clotting, which can increase the risk of bleeding, especially for those on anticoagulant medications.



Cinnamon contains cinnamaldehyde, which can trigger allergic reactions in sensitive individuals. Symptoms may include mouth sores, skin irritation, and respiratory problems. Gastrointestinal discomfort, such as nausea, bloating, or heartburn, is also common when cinnamon is consumed in excess.



Although cinnamon is often praised for its blood sugar-lowering properties, excessive consumption can lead to digestive upset and inconsistent glucose control, particularly if combined with diabetes medications or supplements.







Symptoms of liver stress

Signs of liver stress caused by excessive coumarin intake can include tiredness, nausea, jaundice (yellowing of the skin and eyes), and abdominal discomfort. Recognising these symptoms early is crucial to prevent further damage and seek timely medical care.







How to enjoy cinnamon safely



To enjoy cinnamon without compromising liver health or overall wellbeing, moderation is key. Limit daily intake of Cassia cinnamon to no more than 1 teaspoon (approximately 2–3 grams). Choosing Ceylon cinnamon for daily use is a safer option due to its minimal coumarin content.



Be cautious with cinnamon supplements, which can be highly concentrated and easily exceed safe coumarin levels. Always check product labels, monitor your intake, and consult a healthcare professional if you have liver conditions or take medications.



Pairing cinnamon with protein and healthy fats, and using it as a flavouring rather than the main ingredient, can also reduce its impact on blood sugar and liver stress. Recipes such as overnight oats, smoothies, or lightly spiced teas are excellent ways to enjoy cinnamon safely.








Disclaimer: This article is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional before making any changes to your health routine or treatment.