Contents
What it is
Cinnamon is the dried inner bark of a tree in the laurel family — bark, not a leaf or a fruit, which is unusual among spices; as it dries it curls inward into quills. There are two main kinds. Ceylon cinnamon from Sri Lanka is built of thin layers, crumbles easily and smells delicate; cassia from Southeast Asia and China is thick, hard and much more pungent. What is commonly sold in Korea, and most cheap ground cinnamon anywhere, is cassia. Cassia carries comparatively more coumarin.
Scientific name Cinnamomum
Plenty of articles cover cinnamon and blood sugar, but the more important story is which cinnamon. Ceylon ("true") cinnamon and cassia cinnamon come from different trees, and most ground products are the cheaper cassia.
The difference is coumarin. Cassia contains dozens of times more of it than Ceylon, and coumarin is linked to liver damage at high doses. EFSA sets a tolerable daily intake of 0.1 mg per kg of body weight.
Key benefits
- Moderate evidence
It can flatten the post-meal glucose rise
A meta-analysis of 28 randomised trials in 3,054 people with type 2 diabetes found fasting glucose down 15.3 mg/dL, post-meal glucose down 39.2 mg/dL and HbA1c down 0.56%, most clearly in capsule form at 2 g a day or less. But the trials disagree wildly with each other (I² 88–100%) — the pooled numbers should not be taken at face value. It does not substitute for medication.[1][2]
- Early research
Cinnamaldehyde is antimicrobial and anti-inflammatory
The compound behind cinnamon's aroma shows antibacterial and antifungal activity in laboratory work. That is also the background to cinnamon's long history as a preservative.[3]
- Nutrition data
It creates an impression of sweetness without sugar
Cinnamon is not sweet itself, but its aroma is associated with sweetness, so adding it to coffee or oatmeal keeps satisfaction while you cut sugar. In practice this is its most useful property.
- Nutrition data
High antioxidant scores
Its polyphenol content is among the highest of the spices. But since real intake is only 1–2 g a day, its share of your total antioxidant intake stays small.
How to eat it well
- Choose Ceylon. The label will say so, and Ceylon sticks are rolled from many thin layers; cassia sticks are thick and roll in a single curl.
- 1–2 g a day is enough. Supplement-level doses are not advisable.
- Sprinkled on coffee, oatmeal or yoghurt, it genuinely helps reduce how much sugar you add.
- Add it at the end rather than boiling it, since the aromatic compounds evaporate.
- Remember that cinnamon rolls and similar products are mostly sugar and butter.
How to read the grades
Each benefit carries a label showing how far research on people supports it. Grades differ between items even within the same ingredient.
- Nutrition data
- A fact verifiable from food composition databases or health authorities. This is a different kind of statement from a clinical effect.
- Strong evidence
- Consistently confirmed across randomised controlled trials or meta-analyses.
- Moderate evidence
- Human studies exist, but effect sizes are small or results are mixed.
- Early research
- Cell or animal work, or small preliminary studies.
- Not established
- Commonly claimed, but not confirmed in studies on people.
What to watch out for
- Coumarin in cassia cinnamon is linked to liver damage at high or prolonged intake. The EFSA limit of 0.1 mg per kg body weight works out to roughly 2 g of cassia for a 60 kg adult.
- With liver disease or hepatotoxic medication, avoid cassia and use Ceylon.
- At high doses alongside glucose-lowering drugs, consider the possibility of hypoglycaemia.
- Inhaling dry cinnamon powder can injure the airways and is genuinely dangerous.
- Culinary amounts are fine in pregnancy; therapeutic doses are not recommended.
Nutrition
Approximate values per 100 g of ground cinnamon. Typical use is 1–2 g a day, about half a teaspoon.
- Calories
- 247 kcal12%
- Carbohydrates
- 80.6 g29%
- Fiber
- 53.1 g190%
- Protein
- 4.0 g8%
- Calcium
- 1,002 mg77%
- Manganese
- 17.5 mg761%
- Iron
- 8.3 mg46%
Percentages are of the US FDA Daily Value for adults and children 4 and over. National reference intakes differ by sex and age.
Calculate this alongside other ingredients →
Key nutrients
By health concern
Dishes with this ingredient
Sources
The databases and health authorities this article's nutrition figures and health statements draw on.
- 1The impact of cinnamon on anthropometric indices and glycemic status in patients with type 2 diabetes: A systematic review and meta-analysis of clinical trialsMeta-analysisNamazi N, et al. Complement Ther Med 2019PMID 30935562
- 2Effects of cinnamon supplementation on metabolic biomarkers in individuals with type 2 diabetes: a systematic review and meta-analysisMeta-analysisde Moura SL, et al. Nutr Rev 2025PMID 38917435
- 3Cinnamaldehyde in Focus: Antimicrobial Properties, Biosynthetic Pathway, and Industrial ApplicationsResearch literatureJaramillo Jimenez BA, et al. Antibiotics (Basel) 2024PMID 39596788
- 4USDA FoodData CentralFood composition database
- 5European Food Safety Authority (EFSA)Health authority
- 6Cochrane LibrarySystematic reviews
- 7PubMedResearch literature
