Cinnamon bread: a sweet loaf with a spice's reputation

In a meta-analysis of 28 randomized trials in 3054 adults with type 2 diabetes, cinnamon taken as a supplement lowered fasting blood glucose by about 15 mg/dL over 30 to 120 days (95% CI 8.3 to 22.2), with results that varied widely between trials. A second meta-analysis of 49 placebo-controlled trials in adults found the same direction, with a standardized mean difference of -1.28 for fasting glucose and -0.71 for LDL cholesterol. Those trials gave cinnamon as a supplement. We found no measurement of how much cinnamon or coumarin sits in a slice of cinnamon bread, so none of these effects can be credited to the bread. Those supplement doses come with limits. Cassia cinnamon carries coumarin, whose tolerable daily intake EFSA sets at 0.1 mg per kg of body weight, and NCCIH advises anyone taking a medicine to talk with a clinician before using cinnamon products. No study of cinnamon alongside glucose-lowering drugs was found. What a slice carries is known. A medium 0.99 oz (28 g) slice gives about 71 calories, 4 g of sugars and 109 mg of sodium in the US survey database, and glazed or homemade loaves can differ. The only test of an actual cinnamon bread used a recipe with 3.5 oz (100 g) of coconut flour per kg, in 10 healthy and 10 diabetic adults. That bread and a granola bar landed at a glycemic index of 62.7 to 71.6, and an ordinary loaf was never tested.

The numbers, per 3.5 oz (100 g)

As people eat it, per 3.5 oz (100 g)

How much is actually in it

• Lab analysis of German retail foods found coumarin averaging 9 mg per kg in bakery products and breakfast cereals, with up to 88 mg per kg in some cinnamon cookies. — retail cinnamon-containing foods from German official food control (n = not stated in the abstract) Evidence D source
  Coumarin mean 9 mg/kg in bakery products and breakfast cereals, up to 88 mg/kg in some cinnamon cookies
• A US lab analysis found only traces of coumarin in Ceylon cinnamon but substantial amounts in all three cassia species, and coumarin in every cinnamon-flavored food bought locally. — authenticated cinnamon barks and US retail cinnamon, cinnamon-flavored foods and supplements (n = not stated in the abstract) Evidence D source
  Ceylon (C. verum) bark only traces of coumarin, cassia species substantial amounts; coumarin found in all retail cinnamon foods tested

What a real portion looks like

• A medium slice of cinnamon bread (28 g) provides about 71 calories, 4 g of sugars and 109 mg of sodium. — US survey food Bread, cinnamon Evidence E source
  Per 100 g: 253 calories, total sugars 14.11 g, sodium 388 mg; medium slice 28 g, large slice 43 g

What your body absorbs

• In a randomized crossover test in 10 healthy and 10 diabetic adults, cinnamon bread with 100 g coconut flour per kg and a granola bar with 50 g per kg had glycemic indices between about 63 and 72. — Ten normal and ten diabetic subjects, single test meals after overnight fast (n = 20) Evidence B source
  GI 62.7 to 71.6 for granola bar and cinnamon bread with 50-100 g coconut flour/kg
• In a crossover study in 24 volunteers, coumarin from cassia cinnamon baked into rice pudding was absorbed almost as well as pure coumarin, so the coumarin intake limit applies to cinnamon foods. — 24 healthy volunteers, single 12 mg coumarin doses in four formulations (n = 24) Evidence C source
  Relative absorption 54.7% from rice pudding vs 62.8% for isolated coumarin capsule

What it does to your health

• A meta-analysis of 28 RCTs in 3054 people with type 2 diabetes found cinnamon supplements lowered fasting glucose by about 15 mg/dL over 30 to 120 days. — Adults and older adults with type 2 diabetes, trials of 30-120 days (n = 3054) Evidence A source
  Fasting glucose WMD -15.26 mg/dL (95% CI -22.23 to -8.30), I2 88%
• A meta-analysis of 49 RCTs found cinnamon supplements lowered fasting glucose (SMD -1.28) and LDL cholesterol (SMD -0.71) in adults. — Adults in placebo-controlled RCTs of at least one week, searches to July 2024 (n = 3038) Evidence A source
  Fasting glucose SMD -1.28 (95% CI -1.65 to -0.90); LDL-C SMD -0.71 (95% CI -1.02 to -0.40)

Safety, limits and interactions

• A meta-analysis of 7 RCTs in 256 adults found cinnamon supplements did not significantly change liver enzymes ALT, AST or ALP. — Adults in RCTs of oral cinnamon supplementation, searches to September 2020 (n = 256) Evidence A source
  No significant effect on ALT, AST, ALP overall; ALT -4.01 U/L (95% CI -6.86 to -1.15) in type 2 diabetes
• EU law caps coumarin at 50 mg per kg in traditional or seasonal bakery ware labeled with cinnamon, 15 mg per kg in other fine bakery ware, 20 mg per kg in breakfast cereals and 5 mg per kg in desserts. — compound foods sold in the European Union with added flavorings or cinnamon Evidence E source
  Coumarin maximum 50 mg/kg in traditional or seasonal bakery ware labeled with cinnamon, 20 mg/kg breakfast cereals, 15 mg/kg other fine bakery ware, 5 mg/kg desserts

What people believe that the data does not support

• In a randomized crossover trial in 9 healthy young adults, adding 3 g of cinnamon to a high-fat breakfast did not change gastric emptying, blood glucose or appetite over 360 minutes. — Nine healthy young subjects, single high-fat test meal (n = 9) Evidence B source
  No change in gastric emptying, postprandial triacylglycerol or glucose, appetite

Who this works differently for

• A meta-analysis of 12 RCTs in 773 people with metabolic syndrome found cinnamon cut LDL cholesterol by about 6 mg/dL overall, but showed no lipid effect in European and American patients. — Patients with metabolic syndrome and related disorders in placebo-controlled RCTs (n = 773) Evidence A source
  LDL-C WMD -6.2 mg/dL (95% CI -7.7 to -4.3; metric: -0.16 mmol/L, -0.20 to -0.11); no significant effect in European and American subgroups
• EFSA kept the tolerable daily intake of coumarin at 0.1 mg per kg of body weight, which is 6 mg a day for a 132 lb (60 kg) adult and 2 mg for a 44 lb (20 kg) child. — general population, tolerable daily intake set per kg of body weight Evidence E source
  TDI 0.1 mg coumarin per kg body weight a day (6 mg for a 132 lb (60 kg) adult, 2 mg for a 44 lb (20 kg) child)
• NCCIH advises anyone taking a medicine to talk with a clinician before using cinnamon products, and says Ceylon cinnamon in larger amounts during pregnancy is considered unsafe. — people taking any medicine; pregnant and breastfeeding people Evidence E source
  Advises talking with a clinician before cinnamon products when on any medicine; Ceylon cinnamon in larger amounts in pregnancy considered unsafe
• In its fact sheet on type 2 diabetes and supplements, which covers cinnamon, NCCIH warns that dietary supplements may interact with medications or other supplements. — people with type 2 diabetes considering dietary supplements Evidence E source
  Supplements may interact with medications; no numeric risk given
• A case report describes acute hepatitis in a 73-year-old woman a week after she added cinnamon supplements to a statin, and its authors advise against the combination. — one 73-year-old woman on a statin who started cinnamon supplements (n = 1) Evidence C source
  Acute hepatitis about one week after starting cinnamon supplements, resolved after stopping; statin resumed without problems

The bottom line

The idea that a little cinnamon on a meal steadies blood sugar has one direct test here. In a randomized crossover trial in 9 healthy young adults, 3 g of Ceylon cinnamon added to a high-fat breakfast did not change gastric emptying, blood glucose or appetite over 360 minutes. Nine people and one meal is a thin base. The lipid effects in supplement trials were also uneven. A meta-analysis of 12 trials in 773 people with metabolic syndrome found LDL cholesterol fell by 6.2 mg/dL (0.16 mmol/L) overall, about 6 mg/dL, and found no significant lipid effect in the European and American patients. Cassia cinnamon contains coumarin. In a crossover study in 24 healthy volunteers, coumarin from cinnamon baked into rice pudding was absorbed at 54.7 percent, against 62.8 percent from a pure coumarin capsule. The authors judged that the tolerable daily intake for coumarin can be used for meals containing cinnamon. That study did not state randomization, and nobody has measured coumarin in cinnamon bread. On the liver, a meta-analysis of 7 trials in 256 adults found cinnamon supplements did not significantly change ALT, AST or ALP, in short trials that did not look at coumarin separately. The coumarin limit of 0.1 mg per kg of body weight works out to 6 mg a day for a 132 lb (60 kg) adult and 2 mg for a 44 lb (20 kg) child, so a child reaches it with less cinnamon food. EU law caps coumarin at 50 mg per kg in traditional or seasonal bakery ware labeled with cinnamon and at 15 mg per kg in other fine bakery ware. German retail bakery products and breakfast cereals averaged 9 mg per kg, with up to 88 mg per kg in some cinnamon cookies, in samples taken before those limits applied. A US analysis found only traces of coumarin in Ceylon cinnamon, substantial amounts in cassia, and coumarin in every cinnamon-flavored food it bought. A single case report describes acute hepatitis in a 73-year-old woman a week after she added cinnamon supplements to a statin, which resolved when she stopped. NCCIH says amounts commonly found in foods appear safe in pregnancy in some studies, but considers Ceylon cinnamon in larger amounts unsafe. We found no study of low blood sugar from cinnamon taken with diabetes medicines, and we have no card on cinnamon allergy.

Sources

1. cnbrd-hf2-03 · laboratory food analysis
   In the foods under investigation, appreciable amounts of coumarin were found in bakery products and breakfast cereals (mean 9mg/kg) with the highest concentrations up to 88mg/kg in certain cookies flavoured with cinnamon.
   Sproll C, Ruge W, Andlauer C, Godelmann R, Lachenmeier DW. HPLC analysis and safety assessment of coumarin in foods. Food Chemistry (2008) · checked 2026-10-08
2. cnbrd-hf2-04 · laboratory food analysis
   The experimental results indicated that C. verum bark contained only traces of coumarin, whereas barks from all three cassia species, especially C. loureiroi and C. burmannii, contained substantial amounts of coumarin. ... Coumarin was detected in all locally bought cinnamon, cinnamon-flavored foods, and cinnamon food supplements.
   Wang YH, Avula B, Nanayakkara NP, Zhao J, Khan IA. Cassia cinnamon as a source of coumarin in cinnamon-flavored food and food supplements in the United States. J Agric Food Chem (2013) · checked 2026-10-08
3. cnbrd-daily-r1-08 · food composition and portion data
   Bread, cinnamon (FDC 2707620): Energy 253 kcal; Total Sugars 14.11 g; Sodium 388 mg per 100 g; 1 medium or regular slice 28 g
   USDA FNDDS 2021-2023, Bread, cinnamon, FNDDS 51113010, FDC 2707620 · checked 2026-10-01
4. cnbrd-daily-r1-01 · randomized crossover trial
   Using a randomized crossover design, the control and test foods were fed in random order on separate occasions after an overnight fast. ... On the other hand, granola bar and cinnamon bread with 50 and 100 g coconut flour/kg respectively gave a GI ranging from 62.7 to 71.6 and did not differ significantly from the test foods with 150 g coconut flour/kg (P<0.05).
   Br J Nutr, 2003 · checked 2026-10-01
5. cnbrd-daily-r1-06 · crossover pharmacokinetic study
   The relative extent of absorption measured as urinary excretion of the main metabolite 7-hydroxycoumarin (7OHC) was found to be 62.8% for isolated coumarin in a capsule (reference), 56.0% for cinnamon in capsules, 66.1% for cinnamon tea, and 54.7% for cinnamon in rice pudding (means, n=23, observation period 8 hours). ... Therefore, the TDI of coumarin can be used for risk assessment of coumarin exposure from cinnamon-containing meals.
   Mol Nutr Food Res, 2011 · checked 2026-10-01
6. cnbrd-daily-r1-02 · meta-analysis of RCTs
   In total, 28 RCTs with a duration ranging from 30 to 120 days and a total enrollment of 3054 patients with DM2 were included. Participants consuming cinnamon showed a significant reduction in fasting blood glucose (FBG) (WMD: -15.26 mg/dL; 95% CI: -22.23 to -8.30; I2 = 88%)
   Nutr Rev, 2025 · checked 2026-10-01
7. cnbrd-daily-r1-03 · meta-analysis of RCTs
   Forty-nine studies were included. Cinnamon supplementation significantly reduced WC (SMD = - 0.40; 95% (CI): - 0.73, - 0.06), DBP (SMD = - 1.04; 95% CI: - 1.54, - 0.55), SBP (SMD = - 0.85; 95% CI: - 1.54, - 0.16), fasting glucose (SMD = - 1.28; 95% CI: - 1.65, - 0.90)
   J Health Popul Nutr, 2025 · checked 2026-10-01
8. cnbrd-daily-r1-05 · meta-analysis of RCTs
   A total of seven original trials (nine treatment arms) involving a total of 256 subjects were included in the final analysis. The pooled analysis indicated that cinnamon supplementation had no significant effect on serum levels of ALT, AST, and ALP.
   Phytother Res, 2021 · checked 2026-10-01
9. cnbrd-hf2-02 · regulation
   Coumarin Traditional and/or seasonal bakery ware containing a reference to cinnamon in the labelling 50 Breakfast cereals including muesli 20 Fine bakery ware, with the exception of traditional and/or seasonal bakery ware containing a reference to cinnamon in the labelling 15 Desserts 5
   Regulation (EC) No 1334/2008 on flavourings, Annex III Part B · checked 2026-10-08
10. cnbrd-daily-r1-07 · randomized crossover trial
    A single-blind randomized crossover study assessed nine healthy, young subjects. ... Cinnamon did not change gastric emptying parameters, postprandial triacylglycerol or glucose concentrations, oxidative stress, arterial function or appetite (p < 0.05).
    Cardiovasc Diabetol, 2011 · checked 2026-10-01
11. cnbrd-daily-r1-04 · meta-analysis of RCTs
    Twelve studies involving 773 subjects were included in the meta-analysis. ... In the subgroup analysis, cinnamon did not exhibit a significant effect on lipid profiles in European and American patients.
    Complement Ther Clin Pract, 2022 · checked 2026-10-01
12. cnbrd-hf2-01 · agency risk assessment
    concluded to maintain the TDI of 0.1 mg coumarin/kg bw allocated in the 2004 Opinion.
    EFSA AFC Panel, Coumarin in flavourings and other food ingredients with flavouring properties, EFSA Journal (2008) 793 · checked 2026-10-08
13. cnbrd-hf2-05 · NIH agency page
    If you take any type of medicine, talk with your health care provider before using cinnamon or other herbal products; some herbs and medicines interact in harmful ways. Some studies of the use of Ceylon and cassia cinnamon during pregnancy suggest it is safe in amounts commonly found in foods, but Ceylon cinnamon in larger amounts during pregnancy is considered unsafe.
    NIH National Center for Complementary and Integrative Health, Cinnamon: Usefulness and Safety, updated November 2024 · checked 2026-10-08
14. cnbrd-hf2-06 · NIH agency page
    Keep in mind that dietary supplements may interact with medications or other dietary supplements.
    NIH National Center for Complementary and Integrative Health, Diabetes and Dietary Supplements · checked 2026-10-08
15. cnbrd-hf2-07 · case report
    A combination of cinnamon supplement and statin can cause hepatitis, and it should be discouraged.
    Am J Case Rep, 2015 · checked 2026-10-08