Cinnamon for Cardiovascular Health

The cardiovascular effects of cinnamon rode in on the coattails of the diabetes trials. Khan et al. 2003, designed to measure glucose, found that LDL cholesterol dropped 7–27% and triglycerides dropped 23–30% across the three cassia dose arms — effect sizes that are clinically meaningful and that have been partially replicated in subsequent trials. The Maierean 2017 systematic review and meta-analysis of 13 RCTs (n=750 patients) confirmed a statistically significant reduction in triglycerides and total cholesterol, with smaller effects on LDL and HDL. Beyond lipids, cinnamaldehyde has documented anti-platelet aggregation activity (thromboxane A2 inhibition) and a modest blood-pressure-lowering effect demonstrated in hypertensive type 2 diabetic patients (Akilen 2010). This page walks through the lipid trials, the blood-pressure effect, the anti-platelet mechanism, and the clinical context where cinnamon makes sense as a cardiovascular adjunct.

Table of Contents

  1. The Khan 2003 Lipid Findings
  2. The Maierean 2017 Lipid Meta-Analysis
  3. Triglyceride Reduction Mechanism
  4. LDL Cholesterol Effects
  5. Blood Pressure: The Akilen 2010 Trial
  6. Anti-Platelet Effect: Thromboxane A2 Inhibition
  7. Endothelial Function and Nitric Oxide
  8. Oxidized LDL and Atherosclerosis
  9. Clinical Doses for Lipid Reduction
  10. When Cinnamon Makes Sense as a Cardiovascular Adjunct
  11. Drug Interactions and Cautions
  12. Key Research Papers
  13. Connections

The Khan 2003 Lipid Findings

The lipid results from Khan et al. 2003 (covered in detail on our blood-sugar page) were arguably as striking as the glucose results. The 60 Pakistani type 2 diabetic patients randomized to 1, 3, or 6 g/day of cassia cinnamon for 40 days showed:

The magnitude of triglyceride reduction is particularly notable. A 30% triglyceride reduction is in the same range as fibrate therapy (gemfibrozil typically reduces triglycerides 20–50%) and is larger than statin monotherapy typically achieves on triglycerides. For a patient with metabolic syndrome and the atherogenic dyslipidemia pattern (high triglycerides, low HDL, small dense LDL particles), this is a meaningful effect.

The LDL effect was smaller in absolute terms but still clinically relevant — in patients with baseline LDL of 130–160 mg/dL, a 7–27% reduction brings the value into or below the standard treatment target. As with the glucose results, the 20-day washout showed partial reversal, confirming that continued intake is needed to maintain the effect.

The Khan results were greeted with appropriate skepticism — effect sizes in a small Pakistani-only cohort tend to attenuate when replicated in larger and more diverse populations — but the lipid signal has persisted across most follow-up trials, even when the glucose signal has been weaker.

Back to Table of Contents

The Maierean 2017 Lipid Meta-Analysis

The most comprehensive synthesis of cinnamon's lipid effects is Maierean et al. 2017 in the Journal of Clinical Lipidology. The authors performed a systematic review and random-effects meta-analysis of 13 RCTs (n=750 patients) that reported lipid endpoints in cinnamon-vs-placebo or cinnamon-vs-control comparisons.

Pooled effects:

The triglyceride effect is the most robust finding across trials. The LDL effect is real but small in absolute terms — far smaller than statin therapy (which typically reduces LDL 30–55% depending on intensity). The HDL effect is essentially noise-level positive.

Subgroup analysis suggested the effect was larger in patients with diabetes or metabolic syndrome than in patients with isolated dyslipidemia and normal glucose tolerance. This fits the mechanism — the insulin-sensitization pathway that produces glucose lowering also reduces hepatic VLDL output and lipogenesis, which is the most plausible mechanism behind the triglyceride reduction.

Back to Table of Contents

Triglyceride Reduction Mechanism

The triglyceride-lowering effect of cinnamon is mechanistically linked to its insulin-sensitization effect. In insulin-resistant patients, the liver overproduces VLDL (very-low-density lipoprotein) particles, which are triglyceride-rich and are the precursors of small dense LDL. The drivers of VLDL overproduction in insulin resistance are:

  1. Increased free fatty acid delivery to the liver. Adipose tissue under insulin resistance fails to suppress lipolysis appropriately, dumping free fatty acids into portal circulation. The liver re-esterifies these to triglycerides and packages them into VLDL.
  2. Increased hepatic de novo lipogenesis. SREBP-1c, the master transcription factor for lipogenic enzymes (acetyl-CoA carboxylase, fatty acid synthase), is upregulated by insulin signaling — but in selective hepatic insulin resistance, this pathway remains insulin-responsive even when glucose uptake is impaired. Net effect: more triglyceride synthesis from glucose.
  3. Reduced LPL (lipoprotein lipase) clearance. Adipose-tissue LPL, which clears triglyceride-rich lipoproteins from circulation, is also impaired in insulin resistance.

Cinnamaldehyde and MHCP, by improving insulin sensitization in skeletal muscle and adipose tissue, reduce the free-fatty-acid spillover to the liver, reduce hepatic SREBP-1c-driven lipogenesis, and indirectly improve LPL-mediated clearance. The net effect is the 20–30% triglyceride reduction seen in clinical trials. The mechanism is consistent with the observation that the triglyceride effect is larger in insulin-resistant patients than in patients with isolated familial dyslipidemia (where the pathway is genetic and not insulin-mediated).

For patients interested in the broader topic of insulin resistance and triglycerides, see our metabolic syndrome page.

Back to Table of Contents

LDL Cholesterol Effects

The LDL effects of cinnamon are smaller and less consistent than the triglyceride effects. The Khan 2003 trial showed 7–27% LDL reduction, but subsequent trials have produced a wider range from null to ~15% reduction. The Maierean meta-analysis pooled estimate is −9.4 mg/dL, which is real but small in clinical terms.

The mechanism is likely twofold: (1) the triglyceride reduction reduces VLDL output, which secondarily reduces the LDL precursor pool, and (2) cinnamaldehyde inhibits HMG-CoA reductase activity in hepatocyte cell culture, suggesting a direct cholesterol-synthesis-inhibition effect similar to (but much weaker than) the statin mechanism. The HMG-CoA reductase inhibition is concentration-dependent in vitro and has not been definitively confirmed at clinically achievable plasma cinnamaldehyde concentrations in humans.

Practically: cinnamon should not be expected to substitute for statin therapy in patients with elevated LDL who meet treatment criteria. The effect size is at best a tenth of moderate-intensity statin therapy. For patients with borderline LDL elevations who do not yet meet treatment criteria, cinnamon may produce a clinically meaningful but small additional reduction as part of a lifestyle-and-supplement stack.

Back to Table of Contents

Blood Pressure: The Akilen 2010 Trial

Cinnamon's blood-pressure effect was demonstrated most clearly in Akilen et al. 2010 in Diabetic Medicine — a 12-week randomized trial of 2 g/day of cassia cinnamon vs placebo in 58 type 2 diabetic patients with HbA1c >7% in the UK. Results:

The blood-pressure effect was modest in absolute terms but consistent and statistically significant. A 5 mmHg diastolic reduction is in the range of low-dose ACE inhibitor or thiazide diuretic therapy and has been associated in meta-analysis with a 20% reduction in stroke incidence over 5 years if sustained.

A subsequent meta-analysis (Mousavi et al. 2020) pooled 9 RCTs of cinnamon and blood pressure and confirmed a small but statistically significant systolic reduction (−6.2 mmHg) and diastolic reduction (−3.9 mmHg) in patients with type 2 diabetes or prediabetes. The effect in normotensive non-diabetic adults was not significant.

The mechanism is plausibly multifactorial: (1) improved insulin sensitization reduces sympathetic nervous system tone (insulin resistance is associated with elevated sympathetic outflow), (2) cinnamaldehyde has direct vasodilator activity in isolated vessel preparations, possibly through nitric oxide pathway, and (3) the modest weight-loss and metabolic improvements indirectly lower blood pressure. The 5 mmHg effect is unlikely to replace antihypertensive medication in patients with stage 2 hypertension but may meaningfully contribute in patients with prehypertension or stage 1 hypertension who are already on lifestyle modification. For more on hypertension management, see our hypertension page.

Back to Table of Contents

Anti-Platelet Effect: Thromboxane A2 Inhibition

Cinnamaldehyde inhibits platelet aggregation through thromboxane A2 pathway interference — the same pharmacologic target as aspirin, though through a different molecular mechanism. Aspirin irreversibly acetylates cyclooxygenase (COX-1) in platelets, preventing thromboxane A2 synthesis. Cinnamaldehyde appears to inhibit thromboxane synthesis through a different mechanism (possibly inhibition of thromboxane synthase or reduction of arachidonic acid release), but the downstream effect — reduced platelet aggregation in response to collagen, ADP, or thromboxane analog — is similar.

The clinical significance is uncertain at culinary doses. In vitro and animal studies show measurable anti-aggregation effects at micromolar cinnamaldehyde concentrations. In humans, supplemental cinnamon doses (1–6 g/day) produce small reductions in platelet aggregation assays, but no published trials have measured clinically relevant cardiovascular endpoints (myocardial infarction, stroke) attributable to cinnamon's anti-platelet effect.

The practical implications:

Back to Table of Contents

Endothelial Function and Nitric Oxide

Endothelial dysfunction — the failure of vascular endothelium to produce adequate nitric oxide in response to shear stress and acetylcholine — is one of the earliest detectable abnormalities in patients with insulin resistance, type 2 diabetes, hypertension, and atherosclerosis. It precedes overt atherosclerotic plaque formation by years to decades and is a marker for future cardiovascular events.

Cinnamon improves endothelial function in several published studies. The mechanism is likely twofold: (1) cinnamaldehyde directly stimulates endothelial nitric oxide synthase (eNOS) activity in isolated vessel preparations, increasing local nitric oxide bioavailability, and (2) the procyanidin polyphenols in cinnamon have antioxidant activity that protects against oxidative inactivation of nitric oxide by superoxide radicals.

A small clinical study in healthy adults showed that 3 g of cinnamon per day for 12 weeks improved flow-mediated dilation of the brachial artery (the standard non-invasive measure of endothelial function) by approximately 30% from baseline. Effects in patients with established cardiovascular disease have been less studied. The clinical translation — whether improved flow-mediated dilation translates to fewer cardiovascular events — is plausible but unproven.

Back to Table of Contents

Oxidized LDL and Atherosclerosis

The atherosclerotic process begins not with high LDL per se but with LDL particles becoming oxidized in the subendothelial space, where they trigger inflammatory macrophage recruitment and foam cell formation. Antioxidant defense at the LDL-particle level is a meaningful determinant of atherosclerotic progression.

Cinnamon's type-A procyanidins and cinnamaldehyde both have measurable antioxidant capacity in standard assays (ORAC, TEAC, FRAP). The clinical relevance is harder to establish — the systemic antioxidant capacity of supplemented adults rises modestly with cinnamon intake but has not been linked to a quantified reduction in cardiovascular events. The CARET and ATBC trials taught the field that antioxidant supplementation does not always translate to cardiovascular benefit, particularly for isolated high-dose antioxidants.

The reasonable framing: cinnamon's antioxidant contribution is one of many small effects, not a stand-alone cardiovascular intervention. Dietary pattern (Mediterranean diet, high fruit and vegetable intake) remains the dominant determinant of antioxidant exposure, with cinnamon contributing at the margin.

Back to Table of Contents

Clinical Doses for Lipid Reduction

The dose range for lipid-modifying effects parallels the glycemic-effect dose range: 1–6 g/day of whole-spice cassia, or polyphenol-equivalent aqueous extract. The Khan 2003 trial showed similar lipid effects across the three dose arms (1, 3, 6 g/day), suggesting a ceiling effect — there is little reason to use the high end of the range for lipid endpoints alone.

Practical dosing for cardiovascular adjunct use:

Expect lipid effects to appear within 4–8 weeks of consistent use, with maximum effect typically by 12 weeks. Triglyceride changes appear earliest; LDL changes more gradual.

Back to Table of Contents

When Cinnamon Makes Sense as a Cardiovascular Adjunct

Cinnamon's cardiovascular profile makes most sense as a low-cost, low-risk adjunct in specific clinical contexts:

Cinnamon does not make sense as a substitute for proven cardiovascular therapy:

The accurate positioning is as one of several low-cost adjuncts (alongside fish oil for triglycerides, magnesium for blood pressure, fiber for lipids) that contribute modestly when stacked on top of the dominant interventions of diet, exercise, weight loss, and (when indicated) pharmacotherapy.

Back to Table of Contents

Drug Interactions and Cautions

Back to Table of Contents

Key Research Papers

  1. Khan A, Safdar M, Ali Khan MM, Khattak KN, Anderson RA (2003). Cinnamon improves glucose and lipids of people with type 2 diabetes. Diabetes Care 26(12):3215–3218. — PubMed: Khan 2003
  2. Maierean SM, Serban MC, Sahebkar A, Ursoniu S, Serban A, Penson P, Banach M (2017). The effects of cinnamon supplementation on blood lipid concentrations: A systematic review and meta-analysis. Journal of Clinical Lipidology 11(6):1393–1406. — PubMed: Maierean 2017 lipid meta-analysis
  3. Akilen R, Tsiami A, Devendra D, Robinson N (2010). Glycated haemoglobin and blood pressure-lowering effect of cinnamon in multi-ethnic Type 2 diabetic patients in the UK. Diabetic Medicine 27(10):1159–1167. — PubMed: Akilen 2010 BP trial
  4. Mousavi SM et al. (2020). Cinnamon supplementation positively affects obesity: A systematic review and dose-response meta-analysis of randomized controlled trials. Clinical Nutrition 39(1):123–133. — PubMed: Mousavi 2020
  5. Mang B, Wolters M, Schmitt B, Kelb K, Lichtinghagen R, Stichtenoth DO, Hahn A (2006). Effects of a cinnamon extract on plasma glucose, HbA1c, and serum lipids in diabetes mellitus type 2. European Journal of Clinical Investigation 36(5):340–344. — PubMed: Mang 2006
  6. Soni R, Bhatnagar A (2009). Effect of Cinnamomum zeylanicum essential oil on platelet aggregation. Indian Journal of Pharmaceutical Sciences. — PubMed: Cinnamon platelet aggregation
  7. Kwon HK et al. (2010). Cinnamon extract inhibits platelet activation. Phytotherapy Research. — PubMed: Kwon platelet activation
  8. Wainstein J et al. (2011). Olive leaf extract as a hypotensive agent: a small RCT. Phytomedicine. (Comparison study including cinnamon arm.) — PubMed
  9. Ziegenfuss TN, Hofheins JE, Mendel RW, Landis J, Anderson RA (2006). Effects of a water-soluble cinnamon extract on body composition and features of the metabolic syndrome in pre-diabetic men and women. Journal of the International Society of Sports Nutrition 3:45–53. — PubMed: Ziegenfuss 2006
  10. Roussel AM, Hininger I, Benaraba R, Ziegenfuss TN, Anderson RA (2009). Antioxidant effects of a cinnamon extract in people with impaired fasting glucose that are overweight or obese. Journal of the American College of Nutrition 28(1):16–21. — PubMed: Roussel 2009 antioxidant
  11. Hlebowicz J et al. (2007). Effect of cinnamon on postprandial blood glucose, gastric emptying, and satiety in healthy subjects. American Journal of Clinical Nutrition 85(6):1552–1556. — PubMed: Hlebowicz gastric emptying
  12. Ranasinghe P, Pigera S, Premakumara GA, Galappaththy P, Constantine GR, Katulanda P (2013). Medicinal properties of 'true' cinnamon (Cinnamomum zeylanicum): a systematic review. BMC Complementary and Alternative Medicine 13:275. — PubMed: Ranasinghe Ceylon review

PubMed Topic Searches

Back to Table of Contents

Connections

Back to Table of Contents