Ceylon Cinnamon Nutrition Facts: What's Actually in a Teaspoon (And What Isn't)

The Short Answer: Ceylon Cinnamon Nutrition Facts at a Glance

Per teaspoon (2.6g) breakdown

This is the serving size that matters, because it’s what people actually use.

Nutrient	Per 1 tsp (2.6g)	% Daily Value
Calories	6.4 kcal	<1%
Total carbohydrate	2.1 g	<1%
Dietary fiber	1.4 g	5%
Sugars	0.05 g	negligible
Protein	0.1 g	<1%
Total fat	0.03 g	<1%
Calcium	26 mg	2%
Manganese	0.45 mg	20%
Iron	0.2 mg	1%
Potassium	11 mg	<1%
Magnesium	1.6 mg	<1%
Vitamin K	0.8 mcg	1%
Sodium	0.3 mg	0%

Per tablespoon (7.8g) breakdown

Triple everything. A tablespoon gives you about 19 calories, 6.3g carbohydrate, 4.1g fiber, 78mg calcium, and 1.36mg manganese (roughly 59% DV). I’ll note now that a tablespoon of cinnamon is a lot of cinnamon. If you’ve ever attempted the cinnamon challenge, you know exactly how much.

Per 100g reference values

For completeness: 247 kcal, 80.6g carbohydrate, 53.1g fiber, 3.99g protein, 1.24g fat, 1,002mg calcium, 17.5mg manganese, 8.3mg iron, 431mg potassium, 60mg magnesium, 31.2mcg vitamin K.

Now here’s why I’m skeptical of everyone who leads with that column. When a site tells you cinnamon is “68% of your daily manganese” or “a great source of calcium,” they’re quoting the 100g figure without saying so. It’s technically accurate and practically useless. You’d have to eat a third of a spice jar to get there, and long before you hit any nutritional target you’d be dealing with a mouth that feels like sandpaper.

Two more things you should know before we go further.

The USDA doesn’t distinguish Ceylon from Cassia. FoodData Central lists “Spices, cinnamon, ground” as a single entry. It doesn’t specify species. Given that roughly 90 percent of cinnamon sold in North America is Cassia, that database entry almost certainly reflects Cassia, not Cinnamomum verum. The macronutrients are close enough between species that I’m comfortable using these numbers for Ceylon. The bioactive compounds are not close at all, which brings me to the big one.

Coumarin is the nutrition fact that matters most, and it’s not on any label. Ceylon cinnamon contains roughly 0.017 g/kg of coumarin. Cassia ranges from 0.31 to 6.97 g/kg. That’s a difference of up to 400-fold, and it’s the single reason I’ll argue Ceylon isn’t a gourmet preference but a safety decision for anyone eating cinnamon daily. We’ll get there.

Macronutrients: Why "Zero Calorie" Isn't Quite Right

Calories and where they come from

A teaspoon of Ceylon cinnamon has 6.4 calories. Not zero. Not “free.” Just small enough that it doesn’t matter for anyone who isn’t weighing food to the gram.

Where do those calories come from? Almost entirely carbohydrate. Protein contributes about 0.4 calories, fat contributes about 0.27, and the rest is carbohydrate, most of which is fiber that your small intestine can’t touch. Your colonic bacteria ferment some of it and you recover maybe 1.5 to 2 calories per gram of fermentable fiber, which is why the Atwater-derived label number slightly overstates the metabolically available energy.

Practical translation: a teaspoon of cinnamon gives you somewhere between 3 and 5 usable calories. I’m not going to pretend that’s a meaningful distinction for anyone.

The fiber story (and why it dominates the carb count)

Here’s what surprised me the first time I ran the numbers. Of cinnamon’s 80.6g of carbohydrate per 100g, 53.1g is dietary fiber. That’s 66 percent. For a spice, that’s unusual. Cinnamon is dried inner bark, so you’re consuming ground plant structural tissue, which means lignin, cellulose, and hemicellulose rather than starch.

And that matters for a reason nobody mentions: cinnamon’s fiber is largely insoluble. People assume any “fiber” in a functional food is the soluble, gel-forming, cholesterol-binding kind you get from oats or psyllium. It isn’t. Bark lignin doesn’t form a viscous gel in your stomach. It doesn’t slow gastric emptying the way beta-glucan does. Whatever blood sugar effects cinnamon has (and there are some, discussed later), they’re not coming from fiber-mediated delayed absorption.

Protein and fat: essentially rounding errors

0.1g protein. 0.03g fat. There is nothing more to say. If your protein target depends on cinnamon, something has gone badly wrong with your diet.

Net carbs for keto and low-carb readers

This is the calculation a lot of people land on this page looking for, so let me be explicit:

2.1g total carbohydrate minus 1.4g fiber = 0.7g net carbs per teaspoon.

Sugars are 0.05g, which is a rounding artifact. On a 20g net carb ketogenic day, a teaspoon of Ceylon cinnamon costs you 3.5 percent of your allowance. Two teaspoons in your coffee and yogurt across a day costs 1.4g. That’s fine. Cinnamon is keto-friendly by any reasonable standard.

I’ll be honest about my own habits here. I stopped logging cinnamon in my macros years ago, and the arithmetic that convinced me was this: to accumulate a single gram of net carbs, I’d need 1.4 teaspoons. To accumulate the tracking error of a typical food scale (±1g on a 200g meal), I’d need to be off by more cinnamon than I use in a week. Tracking it was noise pretending to be data.

The fiber myth, killed with math

You’ll see cinnamon described as “a good source of fiber.” Let’s test that. The daily target is 25 to 38g depending on sex and calorie intake. At 1.4g per teaspoon, hitting 25g requires about 18 teaspoons of cinnamon per day.

That’s not happening. It shouldn’t happen. Cinnamon is a flavoring, not a fiber supplement, and anyone selling it as the latter is being generous with the truth.

How it stacks up against other spices

Spice (1 tsp, ground)	Calories	Carbs	Fiber	Net carbs
Ceylon cinnamon (2.6g)	6.4	2.1g	1.4g	0.7g
Turmeric (3.0g)	9.4	2.0g	0.7g	1.3g
Ground ginger (1.8g)	6.0	1.3g	0.25g	1.05g
Ground cloves (2.1g)	5.8	1.4g	0.7g	0.7g
Black pepper (2.3g)	5.8	1.5g	0.6g	0.9g

Notice cinnamon has the highest fiber-to-carb ratio of the group. Cloves come closest. Turmeric, despite its reputation, is the most carb-dense per teaspoon of the five, mostly because a teaspoon of turmeric weighs more.

Micronutrients: The Minerals Worth Mentioning

Calcium: the standout (sort of)

At 1,002mg per 100g, cinnamon looks like a calcium powerhouse on paper. Per teaspoon it delivers 26mg, or 2 percent of the DV. For context, that’s about the calcium in a tablespoon of milk.

Is it useless? Not entirely. If you’re using two or three teaspoons a day across meals, you’re picking up 50 to 80mg of calcium you weren’t counting on. It’s a bonus, not a strategy.

Manganese and the %DV trap

Manganese is the one micronutrient where a realistic serving of Ceylon cinnamon does something. A teaspoon provides roughly 0.45mg, which is 20 percent of the 2.3mg Daily Value. A tablespoon gets you to nearly 60 percent.

So what does manganese actually do? Three things worth knowing:

• It’s the metal cofactor for manganese superoxide dismutase (MnSOD), the antioxidant enzyme that lives inside your mitochondria and neutralizes superoxide radicals produced during energy production. Think of MnSOD as the fire extinguisher mounted next to the furnace.
• It’s required for bone matrix formation, specifically for glycosyltransferases that build the proteoglycans in cartilage and bone.
• It participates in carbohydrate and amino acid metabolism, including the pyruvate carboxylase step of gluconeogenesis.

Frank manganese deficiency is rare in people eating whole grains, nuts, or tea. But if cinnamon is contributing 20 percent of your DV per teaspoon, that’s a legitimate nutritional contribution, and it’s the only one on this list I’d defend.

Now the part that irritates me. Competitor articles routinely publish “cinnamon provides 68% of your daily manganese” without the per-100g qualifier. That’s the 17.5mg figure. It’s a real number attached to an unreal serving. If you see a %DV in a spice article that seems too good to be true, check whether the author quietly switched serving sizes.

Iron, potassium, magnesium

Per teaspoon: 0.2mg iron (1% DV), 11mg potassium (under 1%), 1.6mg magnesium (under 1%), 1.7mg phosphorus.

These are trace contributions. Worse, the iron in cinnamon is non-heme iron sitting in a matrix loaded with polyphenols and tannins, which are well-documented inhibitors of non-heme iron absorption. So the 0.2mg is likely to be absorbed poorly. I wouldn’t count it at all.

Vitamins: K, A, and the trace amounts

Vitamin K1 comes in at 31.2mcg per 100g, which works out to 0.8mcg per teaspoon, or about 1 percent of the adequate intake. Trivial for almost everyone.

Except for one group. If you’re on warfarin and tracking vitamin K intake with the obsessive precision that stable INR requires, know that cinnamon contains some. A teaspoon a day adds 0.8mcg. Consistency matters more than the absolute amount, so if you use cinnamon daily, keep using it daily rather than swinging between zero and three tablespoons.

Vitamin A shows up at 15mcg RAE per 100g, which is 0.4mcg per teaspoon. Round it to zero.

What Ceylon cinnamon does NOT provide

Let me list this plainly, because articles love to imply spices are multivitamins:

• Vitamin B12: zero. Cinnamon is a plant. Plants don’t make B12.
• Vitamin C: the USDA lists 3.8mg per 100g, which is 0.1mg per teaspoon. Ascorbic acid degrades under heat and oxygen during bark drying and curing. Effectively none.
• Vitamin D: zero.
• Sodium: 10mg per 100g, 0.26mg per teaspoon. Genuinely a zero-sodium seasoning, which is the strongest practical argument for cinnamon in a blood-pressure-conscious kitchen.
• Meaningful B vitamins: thiamine, riboflavin, niacin, and B6 all appear in trace quantities that vanish at teaspoon scale.

One more caveat that no lab report will tell you. Mineral content in Ceylon cinnamon varies with soil composition and growing region. Sri Lankan cinnamon from the wet-zone coastal belt around Negombo and Matara grows in different lateritic soils than upland plantations, and mineral uptake follows soil chemistry. I’ve seen supplier certificates of analysis with calcium figures ranging from around 700 to over 1,200 mg per 100g. The USDA number is an average, not a guarantee for the jar in your cupboard.

The Coumarin Question: The Ceylon Cinnamon Nutrition Fact That Actually Matters

What coumarin is and why it’s regulated

Coumarin is a benzopyrone with a sweet, hay-like, vanilla-adjacent aroma. It’s the compound that makes freshly cut grass smell the way it does. It’s also hepatotoxic in susceptible individuals, which is why the FDA banned it as a direct food additive back in 1954 and why European regulators cap it in foods.

In rodents, chronic high-dose coumarin produces liver tumors. In humans the mechanism differs (we metabolize coumarin primarily via 7-hydroxylation rather than the 3,4-epoxidation route that generates toxic intermediates in rats), so the carcinogenicity concern is weaker. The hepatotoxicity concern is not. A subset of people, likely those with lower CYP2A6 activity, develop reversible liver enzyme elevations at intakes that don’t bother anyone else.

The European Food Safety Authority set a tolerable daily intake of 0.1 mg per kg of body weight per day, first in 2004 and reaffirmed in its 2008 opinion. That TDI is for lifelong daily exposure, and EFSA has explicitly said short-term exceedance of up to three times the TDI isn’t a cause for alarm.

Ceylon vs Cassia: the difference isn’t subtle

Cinnamon type	Species	Coumarin (g/kg)	Per teaspoon (2.6g)
Ceylon (“true”)	C. verum / zeylanicum	~0.017	~0.04 mg
Chinese Cassia	C. cassia	~0.31 to 6.97	0.8 to 18 mg
Indonesian Korintje	C. burmannii	often highest in range	frequently 5 to 12 mg
Saigon	C. loureiroi	high	5 to 15 mg

Blahová and Svobodová assessed coumarin in ground cinnamon from the Czech retail market, published in The Scientific World Journal (2012), and found Cassia samples averaging around 3 g/kg while Ceylon samples came in near the detection floor. Germany’s Federal Institute for Risk Assessment (BfR) reached similar conclusions in its 2006 and 2012 risk communications, which is why Denmark briefly restricted cinnamon content in traditional baked goods and set off a minor national scandal about Christmas pastries.

Doing the arithmetic

A 70kg adult gets a TDI of 7 mg of coumarin per day.

• Cassia at 3 g/kg (a mid-range figure): one teaspoon (2.6g) delivers 7.8 mg. You’ve exceeded the TDI with a single teaspoon.
• Cassia at 6.97 g/kg (Korintje, high end): one teaspoon delivers 18 mg. That’s 2.6 times the TDI.
• Ceylon at 0.017 g/kg: one teaspoon delivers 0.044 mg. You’d need roughly 160 teaspoons to reach the TDI.

Read those numbers again. That’s not a small margin. That’s not even close.

Why children are the highest-risk group

The TDI scales with body weight, and children have very little of it. A 15kg four-year-old has a TDI of 1.5 mg per day. At mid-range Cassia potency, that’s half a gram of cinnamon, roughly a fifth of a teaspoon.

A generous dusting of cinnamon sugar on toast. One large cinnamon roll. A couple of servings of cinnamon breakfast cereal. Any of these can put a small child over the TDI, and the BfR specifically flagged children as the population most likely to exceed it through ordinary holiday baking. This is the scenario I’d actually worry about, more than any adult supplement habit.

The case reports

They exist, and they’re worth taking seriously without overstating them. Brancheau, Patel and Zhu documented a case of acute hepatitis in The American Journal of Case Reports (2015) in a patient taking cinnamon supplements alongside a statin, with liver enzymes normalizing after the cinnamon was stopped. Other published cases describe similar patterns: supplement-dose Cassia, transaminase elevation, resolution on withdrawal, sometimes recurrence on rechallenge.

These are individual reports, not a controlled trial, and the absolute risk from culinary amounts is low. But every documented case I’m aware of involves Cassia or unspecified cinnamon at supplement doses. Not Ceylon.

My position

If you use cinnamon occasionally, on oatmeal twice a week, the species barely matters. Sprinkle whatever’s in the cupboard.

But if you’re taking cinnamon daily for blood sugar, or putting a teaspoon in your coffee every morning, or giving it to your kids regularly, Ceylon isn’t a preference. It’s the only defensible choice. The extra $4 a jar buys you a 200-fold reduction in your hepatotoxin exposure. I don’t think that’s a close call.

Two caveats, because I’d rather be accurate than clean. First, Ceylon’s coumarin content isn’t literally zero. It’s low enough to be near the detection limit of many assays, and some analyses report trace values above 0.017 g/kg depending on batch and method. Second, retail “Ceylon” is sometimes adulterated with Cassia. DNA barcoding studies of the international spice trade have repeatedly turned up mislabeled product. Buy from suppliers who publish origin and, ideally, coumarin testing. If your “Ceylon” is dark reddish-brown, hard as a stick, and smells aggressively spicy rather than delicately sweet, be suspicious.

Beyond the Label: Bioactive Compounds Most Ceylon Cinnamon Nutrition Facts Skip

Everything above is the boring part. The interesting chemistry doesn’t appear on any nutrition panel.

Cinnamaldehyde: the flavor and the pharmacology

Cinnamaldehyde is the dominant aromatic in cinnamon bark oil, and here’s the split that explains everything about taste:

• Ceylon bark oil: roughly 50 to 63 percent cinnamaldehyde
• Cassia bark oil: frequently over 90 percent

That’s why Ceylon tastes milder, sweeter, and more floral, while Cassia hits you with that hot, one-note punch familiar from cinnamon gum and snickerdoodles. If you’ve switched to Ceylon and thought “this tastes weaker,” you weren’t imagining it. It is weaker in cinnamaldehyde, by design of the plant.

Pharmacologically, cinnamaldehyde is a TRPA1 agonist (the same receptor channel that responds to mustard oil and wasabi), which is part of why it produces warmth and mild irritation. It’s also the compound driving most of cinnamon’s antimicrobial activity in vitro.

Cinnamic acid and eugenol

Cinnamaldehyde oxidizes to cinnamic acid, which is a precursor in the plant’s phenylpropanoid pathway and shows up in cinnamon extracts.

More interesting to me is eugenol. Ceylon bark oil contains meaningfully more of it than Cassia, in the range of a few percent up to about 10 percent depending on the analysis and plant part (Ceylon leaf oil is a different animal entirely, running 70 to 90 percent eugenol, which is why it smells like cloves). Eugenol is the compound behind clove’s numbing, analgesic quality. It’s a big part of why Ceylon has a rounder, more complex aroma. Cassia essentially lacks it.

Proanthocyanidins and polyphenols

Cinnamon is dense in polyphenols, and the specific class that matters is type A doubly-linked procyanidin oligomers.

Let me explain that without hand-waving. Procyanidins are chains of flavan-3-ol units (the same building blocks found in cocoa and grape seed). Most procyanidins in food are “type B,” connected by a single carbon-carbon bond between units. Cinnamon’s are predominantly “type A,” which have an additional ether bond linking the units, creating a doubly-linked, more rigid, more compact structure. That second bond changes the molecule’s shape and its ability to interact with proteins, and it’s the structural feature most strongly associated with the insulin-signaling effects seen in cell culture.

Anderson and colleagues characterized these polymers in the Journal of Agricultural and Food Chemistry (2004), showing that the type-A trimers and tetramers isolated from cinnamon increased insulin-dependent glucose uptake in vitro while type-B procyanidins from other sources did not.

MHCP and the insulin-signaling research

The earlier work came from the same USDA group. Jarvill-Taylor, Anderson and Graves, writing in the Journal of the American College of Nutrition (2001), isolated a methylhydroxychalcone polymer (MHCP) from cinnamon and demonstrated that it stimulated glucose uptake and glycogen synthesis in 3T3-L1 adipocytes, activated glycogen synthase, and inhibited glycogen synthase kinase-3β. In other words, it behaved like insulin, and it potentiated insulin’s effects when both were present.

Here’s my honest read on that. It’s genuinely good mechanistic work, and it’s the origin of essentially every “cinnamon for blood sugar” claim you’ve ever seen. But it’s fat cells in a dish. The leap from adipocyte glucose uptake to a measurable HbA1c change in a human being is enormous, and the clinical trials that followed have been inconsistent (I’ll get into that evidence in detail later).

ORAC values and antioxidant capacity, with the caveats

Ground cinnamon scores 131,420 μmol TE per 100g on the ORAC scale, one of the highest values ever recorded for a food. Cloves beat it. Almost nothing else does.

And I want you to mostly ignore that number.

Here’s why. The USDA withdrew its ORAC database entirely in 2012, stating that the values were being misused in marketing and that in-vitro antioxidant capacity has no demonstrated relationship to health outcomes in humans. ORAC measures how well a compound quenches peroxyl radicals in a test tube. Your bloodstream is not a test tube. Polyphenol bioavailability is often under 5 percent, the absorbed fraction gets rapidly conjugated by phase II enzymes into metabolites with different activity, and the compounds that survive frequently work through signaling pathways (Nrf2 activation, for instance) rather than direct radical scavenging.

A high ORAC number tells you a food is rich in phenolics. That’s it.

What you absorb depends on how you consume it

This distinction gets lost constantly, and it’s the practical takeaway from this whole section.

Water-soluble compounds (the type-A procyanidins, MHCP, most phenolic acids) extract into water. They’re what you get in cinnamon tea, in a water-based extract, and in the standardized aqueous extracts used in most clinical trials. They’re also what you get when you eat the whole ground bark, since the powder passes through and releases them.

Fat-soluble compounds (cinnamaldehyde, eugenol, the entire essential oil fraction) do not extract meaningfully into water. They partition into oil. Cinnamon essential oil is concentrated in these and contains essentially none of the procyanidins.

So: if you’re steeping a cinnamon stick in hot water and expecting cinnamaldehyde’s effects, you’re getting aroma and very little compound. If you’re using cinnamon oil and expecting the insulin-signaling polyphenols, they aren’t in there. And whole ground Ceylon cinnamon, eaten as food, is the only form that delivers both fractions at once.

That last point has real consequences for dosing, which is where things get genuinely contentious.

That last point has real consequences for dosing, which is where things get genuinely contentious.

What the Ceylon Cinnamon Nutrition Facts Translate To: Blood Sugar, Lipids, and Inflammation

Numbers on a label are inert. What matters is whether 2.6 grams of bark powder does anything measurable inside a human being. I’ll be straight about where the data is strong and where it’s mostly wishful thinking.

Blood glucose and HbA1c: what the meta-analyses show

The study that started this entire conversation came out of Peshawar, Pakistan. Khan et al., published in Diabetes Care (2003), randomized 60 people with type 2 diabetes to 1, 3, or 6 grams of cinnamon daily for 40 days. Fasting glucose dropped 18 to 29 percent across all three dose groups. Triglycerides fell 23 to 30 percent. LDL dropped 7 to 27 percent.

Those are pharmaceutical-sized effects from a spice. Predictably, the supplement industry has been quoting that paper for twenty-two years.

Here’s the problem. The effect size was so large that nobody has come close to replicating it in a Western population. Baseline fasting glucose in those participants was around 220 mg/dL, which is poorly controlled diabetes, and the further you start from normal the more room there is to fall.

The pooled data tells a more sober story. Allen et al. (2013, Annals of Family Medicine) combined 10 randomized controlled trials covering 543 patients with type 2 diabetes. Their results: fasting glucose down about 24.6 mg/dL, total cholesterol down 15.6 mg/dL, LDL down 9.4 mg/dL, triglycerides down 29.6 mg/dL, HDL up 1.7 mg/dL. All statistically significant. But HbA1c? No significant change.

That HbA1c gap matters more than most articles admit. Fasting glucose is a single snapshot; HbA1c reflects roughly three months of average glycemia. A supplement that moves the snapshot but not the average is doing something small.

The trials that found nothing

I trust a body of evidence more when I’ve read the negative results, so let me lay them out.

Baker and colleagues published a meta-analysis in Diabetes Care in 2008 pooling five trials and 282 participants. No significant effect on HbA1c, fasting glucose, or lipids. Flat.

The Cochrane review (Leach and Kumar, 2012) assessed 10 trials with 577 participants and concluded there was insufficient evidence to support cinnamon for type 1 or type 2 diabetes. Cochrane reviews are famously conservative, but “insufficient evidence” from Cochrane is not a ringing endorsement.

Blevins et al. gave 1 gram of cinnamon daily to 57 American adults with type 2 diabetes for three months. Nothing moved. Vanschoonbeek’s team ran 1.5 grams daily in postmenopausal women with type 2 diabetes and found no change in insulin sensitivity or glycemic control.

And here’s the one that should give Ceylon enthusiasts pause: Wickenberg and colleagues tested 6 grams of Cinnamomum zeylanicum (actual Ceylon, not Cassia) on postprandial glucose and insulin in people with impaired glucose tolerance. Published in the British Journal of Nutrition (2012). No significant effect on either.

So which is it? My read: the effect is real in people with meaningfully elevated fasting glucose, it’s modest, and it shrinks toward zero as baseline control improves. If your fasting glucose is 92, cinnamon is not going to move it. If it’s 180 and you’re on metformin, it might shave a few points. That’s the honest version.

Lipid effects: modest but real

The lipid data is actually more consistent than the glucose data, which surprised me. Across Allen’s pooled analysis and several individual trials, total cholesterol and triglycerides move in the right direction with reasonable reliability. Triglyceride reductions in the 20 to 30 mg/dL range showed up repeatedly.

Is that clinically meaningful on its own? For most people, no. It’s the equivalent of a small dietary change. But it’s directionally consistent, and unlike the glucose data it doesn’t seem to require terrible baseline numbers to show up.

Anti-inflammatory and antimicrobial data

Cinnamaldehyde suppresses NF-kB signaling and downstream inflammatory cytokines in cell culture. The procyanidins activate Nrf2, the transcription factor that switches on your endogenous antioxidant enzymes. Both mechanisms are well characterized.

In humans? Thin. A handful of small trials have shown reductions in CRP and malondialdehyde with cinnamon supplementation, mostly in people with type 2 diabetes or metabolic syndrome, mostly with Cassia, mostly underpowered.

Antimicrobial activity is where the in-vitro data is genuinely impressive. Cinnamaldehyde and cinnamon essential oil inhibit Listeria monocytogenes, Salmonella, E. coli, and Candida albicans at low concentrations in laboratory assays. Food scientists have studied cinnamon extracts as natural preservatives for exactly this reason.

But I want to be unambiguous: that’s a petri dish. Getting antimicrobial concentrations of cinnamaldehyde into your gut or bloodstream by sprinkling powder on oatmeal is not happening. Anyone telling you cinnamon treats candida overgrowth is extrapolating across about four orders of magnitude.

The Ceylon-specific evidence gap

Now for the thing almost nobody says out loud.

The overwhelming majority of clinical trials on cinnamon (including Khan 2003, including most of what Allen pooled, including the trials Cochrane assessed) used Cassia, not Ceylon. Cassia is cheaper, more available, and higher in cinnamaldehyde. Researchers used what was in the warehouse.

Reviews of Cinnamomum zeylanicum specifically, including the 2016 assessment in the Journal of Traditional and Complementary Medicine, have repeatedly flagged that human trials on Ceylon remain limited, small, and heterogeneous compared to the Cassia literature.

So the situation is faintly absurd: Ceylon is the safer species, the one you should be eating daily, and the one with the thinner evidence base for the benefits people buy it for. The Wickenberg trial, one of the few genuinely Ceylon-specific studies, was negative.

My position, stated plainly: the metabolic effects of cinnamon are real but modest, the Ceylon-specific human evidence is weaker than marketing implies, and anyone telling you cinnamon replaces a diabetes medication is selling something. Use it as a spice that may contribute a small metabolic nudge. Not as therapy.

Ceylon Cinnamon Nutrition Facts vs Cassia: The Side-by-Side Comparison

Macronutrients between the two species are nearly identical. Everything that matters is in the trace compounds.

Side-by-side nutrition table

Per 1 tsp (2.6 g)	Ceylon (C. verum)	Cassia (C. cassia)
Calories	6.4	6.4
Total carbs	2.1 g	2.1 g
Fiber	1.4 g	1.4 g
Net carbs	~0.7 g	~0.7 g
Manganese	0.46 mg (20% DV)	0.45 mg (20% DV)
Calcium	26 mg (2% DV)	26 mg (2% DV)
Coumarin	~0.005 to 0.05 mg	~5 to 12 mg
Cinnamaldehyde (of oil)	50 to 63%	70 to 90%
Eugenol (of oil)	4 to 10%	trace to none
Price per ounce (US retail)	$2.00 to $4.00	$0.40 to $1.00

Read the coumarin row again. That’s a difference of roughly 100 to 1,000-fold, and it’s the single reason this comparison exists. The European Food Safety Authority set a tolerable daily intake for coumarin at 0.1 mg per kg of body weight. For a 70 kg adult that’s 7 mg a day. One teaspoon of Cassia can hit or exceed that on its own. One teaspoon of Ceylon uses up less than 1 percent of it.

Eugenol is the other giveaway. It’s the clove-like compound that gives Ceylon its softer, more complex aroma, and it’s essentially absent from Cassia. If your cinnamon smells one-dimensionally hot and sweet, it’s Cassia.

Appearance, texture, and how to tell them apart

Whole quills are easy once you’ve held both.

Ceylon quills are thin, papery, and made of many fine layers rolled together like a cigar. They’re brittle. You can crush one between your fingers, and I mean actually crumble it, no grinder needed. Color is a light tan to golden brown.

Cassia quills are thick, hard, and typically a single layer of bark curled inward from both edges (a hollow double-scroll). They’re reddish-brown to dark brown, and trying to snap one with your fingers is a losing proposition. Most bakers own a spice grinder specifically because of Cassia.

Ground powder is subtler but still distinguishable. Ceylon powder is finer, paler, tan-brown. Cassia powder is coarser and noticeably redder. Side by side on a white plate, the difference is obvious. In isolation, less so.

Flavor and culinary use

Ceylon is delicate, citrusy, faintly floral. It disappears in a heavy spice blend and shines in custards, rice pudding, poached fruit, and anything where you want cinnamon to be a note rather than a shout.

Cassia is aggressive. It’s the flavor of a cinnamon roll, a snickerdoodle, a Red Hot. In chili, mole, or Vietnamese pho, Cassia is arguably the right choice, and I say that as someone who keeps both jars.

Substituting Ceylon for Cassia one-for-one in a recipe usually leaves the result tasting underspiced. Use about 1.5 times as much.

Price difference and why it exists

Ceylon runs roughly 3 to 5 times the price of Cassia. That’s not a premium markup on a marketing story.

Sri Lanka produces the large majority of the world’s true cinnamon, and harvesting is skilled manual labor. Workers cut two-year-old shoots, scrape the outer bark, loosen the inner bark by hand-rubbing with a brass rod, peel it off in sheets, and nest the sheets into quills that dry for days. It takes years to train a peeler. Cassia, by contrast, is stripped in thick slabs from trees across Indonesia, China, and Vietnam and dried in the sun.

You’re paying for labor and for a narrower supply base. In my view it’s worth it, but only if what’s in the jar is actually Ceylon.

How to spot fake or adulterated Ceylon

This is not hypothetical. Wang and colleagues analyzed cinnamon and cinnamon-flavored products sold in the United States, publishing in the Journal of Agricultural and Food Chemistry (2013), and found Cassia-type chemical markers dominating the retail supply, including in products where consumers assumed otherwise. Coumarin turned up where the label implied it shouldn’t be.

What I check before buying:

• The Latin binomial. The label should say Cinnamomum verum or Cinnamomum zeylanicum. If it just says “cinnamon” or “Ceylon-style,” pass. “Cinnamomum burmannii” is Indonesian Cassia. “Cinnamomum loureiroi” is Saigon Cassia, the highest-coumarin type of all.
• Country of origin. Sri Lanka. Occasionally the Seychelles or Madagascar. Not Indonesia, China, or Vietnam.
• A coumarin certificate of analysis. Serious sellers test and publish. Most don’t. The ones that do are telling you something.
• The physical test. Buy quills once. If they don’t crumble in your hand, you’ve learned something about that supplier.

Serving Sizes, Dosage, and Practical Use

Culinary amounts vs supplemental amounts

Most people who use cinnamon daily land somewhere between a quarter teaspoon and one teaspoon. Call it 0.65 to 2.6 grams. That’s the range that fits into food without dominating it.

Clinical trials cluster at 1 to 6 grams daily, which is roughly half a teaspoon to two and a half teaspoons. So culinary intake and research intake genuinely overlap at the low end, which is unusual for a botanical and one of the reasons cinnamon gets so much attention.

Where I draw a line: 6 grams a day is a supplement dose, not a food dose, and it should be Ceylon or a water-based extract. Nobody should be taking 6 grams of Cassia daily. That’s 30 to 70 mg of coumarin, roughly five to ten times the tolerable daily intake, every day, indefinitely.

Whole bark vs ground vs extract

Three formats, three different nutritional realities.

Whole quills give you everything, but only what you extract. Steeped in water you’ll pull out procyanidins and phenolic acids and very little cinnamaldehyde. Simmered in a milk-based chai you’ll get more of the oil fraction, because fat is the solvent cinnamaldehyde likes.

Ground powder consumed as food is the only format that delivers the complete package: fiber, minerals, water-soluble polyphenols, and fat-soluble aromatics all at once. It’s also the format the USDA nutrition data actually describes.

Water-based extracts are the genuinely underappreciated option. Because coumarin is fat-soluble and the insulin-signaling type-A procyanidins are water-soluble, an aqueous extract concentrates the compounds most trials tested while leaving coumarin behind almost entirely. Several of the standardized extracts used in research (the Cinnulin PF-type preparations) work on exactly this principle. If your goal is metabolic rather than culinary, that’s the smarter delivery system.

Timing: does it matter?

Honestly, the timing evidence is weak. Nobody has run a proper crossover trial comparing morning versus evening cinnamon.

That said, taking it with a carbohydrate-containing meal has the most theoretical justification, because the proposed mechanisms (enhanced insulin receptor signaling, slowed gastric emptying, alpha-glucosidase inhibition) all act on postprandial glucose. If you’re going to have it once a day, have it with your biggest carb load. That’s reasoning, not proof, and I’ll flag it as such.

How to actually get it into your diet

Practical stuff. Half a teaspoon stirred into oatmeal or overnight oats. A quarter teaspoon added to coffee grounds before brewing (it does not make coffee taste like a candle if you keep the dose modest). Whisked into plain Greek yogurt with a little vanilla. Tossed onto roasted sweet potatoes or carrots with olive oil. Simmered as quill tea, one broken quill per cup, ten minutes.

I put it on roasted vegetables more than anything else. Ceylon’s citrus note works with caramelized root vegetables in a way Cassia’s heat doesn’t.

Storage and shelf life

Here’s something the nutrition label will never tell you: your cinnamon is probably weaker than the data suggests.

Ground cinnamon loses meaningful volatile oil within about six months. The minerals stay put (manganese doesn’t evaporate), the fiber stays put, but the cinnamaldehyde and much of the aromatic fraction fade. Whole quills hold their potency for two to three years because the oils are locked inside intact bark cells.

So if that jar has been open since 2023, the nutrition facts on the back are optimistic about everything that isn’t a mineral. Buy small quantities. Store in dark glass, away from the stove. Better yet, buy quills and grind as needed.

Safety, Side Effects, and Who Should Be Careful

Realistic risks at culinary doses

At a quarter to one teaspoon a day, Ceylon cinnamon is about as risky as oregano. The entire cinnamon safety conversation, the liver warnings, the coumarin limits, the “don’t exceed one teaspoon” advice floating around the internet, is really a Cassia conversation that got attached to the word “cinnamon.”

Germany’s Federal Institute for Risk Assessment issued warnings about coumarin in cinnamon-heavy baked goods in the mid-2000s specifically because Cassia dominated the market. Coumarin is hepatotoxic in sensitive individuals at sustained high intakes, with liver enzyme elevations that typically reverse on withdrawal. Ceylon’s coumarin content is low enough that reaching problematic intakes would require eating tablespoons daily.

Oral irritation and cinnamaldehyde allergy

This one’s more common than people expect. Cinnamaldehyde is a well-documented contact allergen. It causes perioral dermatitis, cheilitis, burning mouth, and oral mucosal irritation, and the usual culprits aren’t spice jars at all. They’re cinnamon-flavored chewing gum, toothpaste, mouthwash, and candy, where synthetic or concentrated cinnamaldehyde sits against mucosa for extended periods.

If your mouth burns or peels after cinnamon gum, that’s cinnamaldehyde sensitivity, and Ceylon powder in food may bother you too (Ceylon has less cinnamaldehyde but not zero).

Drug interactions worth knowing

Two worth flagging.

Glucose-lowering medications. If cinnamon has any hypoglycemic effect (modest, as covered above) it’s additive with metformin, sulfonylureas, or insulin. The realistic risk is low at culinary doses, higher with gram-level extracts, and highest with sulfonylureas and insulin where hypoglycemia is already on the table. Monitor if you’re adding a supplement dose.

Hepatotoxic drugs. If you’re on acetaminophen regularly, statins, methotrexate, or anything else that taxes the liver, high-dose Cassia is a bad combination. Ceylon sidesteps this almost entirely, which is precisely why I recommend it for anyone using cinnamon daily and long-term.

The cinnamon challenge and aspiration risk

Dry cinnamon powder inhaled into the airway is genuinely dangerous. It doesn’t dissolve, and the cellulose fibers are not cleared efficiently from the lungs. Animal work has shown inflammatory and fibrotic changes after inhalation exposure.

The “cinnamon challenge” internet trend produced real casualties. American poison centers logged 222 cinnamon-misuse calls involving adolescents in 2012, a sharp jump from prior years, with documented emergency department visits for aspiration, and at least one case requiring ventilator support. The Pediatrics case series by Grant-Alfieri and colleagues (2013) documented it thoroughly.

Swallowing a teaspoon of cinnamon: fine. Attempting to swallow a tablespoon dry: don’t.

Pregnancy and pediatric considerations

Culinary cinnamon during pregnancy is fine, and Ceylon is the clearly better choice given the sustained coumarin exposure question. Same logic for children, who have lower body weights and therefore hit the coumarin tolerable daily intake faster. A 20 kg child’s TDI is 2 mg, which a single cinnamon-heavy pastry made with Cassia can approach.

What I’d avoid in pregnancy: cinnamon supplements and cinnamon essential oil taken internally. Not because there’s evidence of harm, but because there’s essentially no safety data, and a concentrated botanical extract is a different risk category from sprinkling powder on toast. That distinction (food versus supplement) is the one people collapse most often, and it’s the one that actually matters.

Frequently Asked Questions

How many calories are in a teaspoon of Ceylon cinnamon?

One teaspoon of ground Ceylon cinnamon (2.6 grams) contains about 6.4 calories. That breaks down to 2.1 grams of carbohydrate, 1.4 grams of fiber, 0.1 grams of protein, and 0.03 grams of fat. Because fiber makes up two-thirds of the carbohydrate, the metabolically available energy is closer to 3 to 4 calories. In practical terms, cinnamon’s calorie contribution to any dish is a rounding error. Cassia has essentially identical calorie and macronutrient values.

Is Ceylon cinnamon nutritionally better than Cassia cinnamon?

Nutritionally they’re nearly identical in calories, fiber, manganese, and calcium. The difference is coumarin: Ceylon contains roughly 0.005 to 0.05 mg per teaspoon versus 5 to 12 mg for Cassia, a 100 to 1,000-fold gap. Coumarin is hepatotoxic at sustained high intakes, with a tolerable daily intake of 0.1 mg per kg body weight. Ceylon is better for daily use. Cassia has more cinnamaldehyde and a stronger flavor, so it’s arguably better for occasional baking.

How much Ceylon cinnamon is safe to eat per day?

Ceylon’s low coumarin means 1 to 2 teaspoons (2.6 to 5.2 grams) daily is comfortably safe for most adults, and even higher intakes don’t approach coumarin limits. Clinical trials have used up to 6 grams daily without significant adverse effects. Compare that to Cassia, where a single teaspoon can exhaust a 70 kg adult’s 7 mg daily coumarin allowance. Start at half a teaspoon if you’re new to it, and drop the dose if you notice mouth or lip irritation.

Does Ceylon cinnamon actually lower blood sugar?

Modestly, and mainly in people with elevated fasting glucose. Allen et al. (2013) pooled 10 randomized trials in 543 people with type 2 diabetes and found fasting glucose fell about 24.6 mg/dL, though HbA1c didn’t change significantly. Baker’s 2008 meta-analysis and the 2012 Cochrane review found no significant benefit. Most of those trials used Cassia. One Ceylon-specific trial in the British Journal of Nutrition (2012) found no postprandial glucose effect at all. Real but small, and not a medication substitute.

How long does it take for Ceylon cinnamon to work?

Acute postprandial effects, if they occur, happen within the same meal (30 to 120 minutes). Measurable changes in fasting glucose in trials typically appeared at 4 to 12 weeks of daily supplementation. Khan et al. (2003) saw effects at 40 days. Lipid changes in pooled analyses generally showed up at 8 to 16 weeks. If you’ve taken it daily for three months with no change in your fasting numbers, it likely isn’t doing much for you.

Does Ceylon cinnamon contain coumarin at all?

Yes, just very little. Ceylon typically contains 0.002 to 0.02 mg of coumarin per gram, meaning about 0.005 to 0.05 mg per teaspoon. Cassia contains 2 to 5 mg per gram, sometimes higher in Saigon varieties. You’d need to eat roughly 140 to 1,000 teaspoons of Ceylon to reach the 7 mg tolerable daily intake for a 70 kg adult. Some batches test at literally undetectable levels, but “very low” is more accurate than “zero.”

Is Ceylon cinnamon keto-friendly, and how many net carbs does it have?

Yes. One teaspoon has 2.1 grams total carbohydrate minus 1.4 grams fiber, leaving about 0.7 grams of net carbs. Even at two teaspoons a day you’re adding under 1.5 grams. Sugar content is negligible at roughly 0.06 grams per teaspoon. Cinnamon is one of the most keto-compatible flavoring agents available, and it adds sweet aromatic character without sweetener, which is genuinely useful on a low-carb diet.

Does Ceylon cinnamon break a fast?

A quarter to half teaspoon in coffee or tea contributes 1.6 to 3.2 calories and about 0.2 to 0.35 grams of net carbs. That will not meaningfully raise insulin or interrupt a fast for weight or metabolic purposes. If you’re fasting for a medical test requiring absolutely nothing by mouth, skip it. For intermittent fasting, cinnamon in black coffee is fine, and the polyphenols may even blunt the glucose response to your first meal.

How can I tell if my Ceylon cinnamon is real?

Check the label for Cinnamomum verum or Cinnamomum zeylanicum and Sri Lanka as country of origin. Then check the product itself: Ceylon quills are thin, papery, multi-layered, tan-colored, and crumble between your fingers, while Cassia quills are thick, hard, reddish-brown, and won’t break by hand. Ground Ceylon is finer and paler than Cassia’s coarse reddish powder. Best assurance is a third-party coumarin certificate of analysis, which reputable sellers publish.

What I'd Actually Take Away From This

The ceylon cinnamon nutrition facts that matter aren’t the ones on the front of the jar.

Calories, carbs, and fat are all effectively zero at real serving sizes. The manganese number is the only vitamin or mineral worth a mention (20 percent of your daily value in a single teaspoon, which genuinely surprised me the first time I ran the numbers). The fiber is real but small.

Everything else that makes cinnamon interesting lives in compounds that don’t appear on a nutrition panel at all: the type-A procyanidins that interact with insulin signaling, the cinnamaldehyde driving aroma and antimicrobial activity in vitro, the eugenol that gives Ceylon its softer profile, and the coumarin that Ceylon almost entirely lacks.

That last one is the whole argument. Not because Ceylon does more, but because it does less harm at the doses people actually consume. If cinnamon is a once-a-month baking ingredient, buy Cassia and enjoy the stronger flavor. If it’s in your coffee every morning, Ceylon is the obvious choice, and paying three times as much for something that costs a few dollars an ounce is not a hard financial decision.

What I won’t tell you is that a teaspoon of bark powder will fix your fasting glucose. The pooled evidence says modest, inconsistent, mostly studied in Cassia, and largely absent in people whose numbers are already decent. I came into this literature expecting to debunk it and ended up somewhere in between: there’s a real signal, it’s small, and it’s been oversold by roughly an order of magnitude.

Use it because it makes oatmeal, roasted carrots, and coffee taste better. Take the manganese and the fiber as free. Treat any metabolic benefit as a bonus rather than a plan.

And check the Latin name on the jar. That single habit does more for you than any dosing protocol.

Frequently Asked Questions