Cinnamon: benefits, dosage, contraindications
Scientific name(s)
Cinnamomum verum
Family or group:
Plants
Active ingredients:
Proanthocyanidins
Polyphenols
Indications
Scoring methodology
EFSA approval.
Type 2 diabetes ✪✪✪✪✪
Some clinical studies of cinnamon in diabetic patients have found significant benefits, while others have failed to confirm those benefits. The best evidence comes from a meta-analysis of these clinical trials, which included 543 adults with type 2 diabetes. The results show that taking 120 mg to 6 grams of cassia cinnamon per day for 4 to 18 weeks reduces fasting blood glucose by an average of 25 mg/dL, total cholesterol by 16 mg/dL, low-density lipoprotein (LDL) cholesterol by 9 mg/dL, and triglycerides by 30 mg/dL, and increases high-density lipoprotein (HDL) cholesterol by 2 mg/dL. In contrast, cinnamon has no effect on glycated hemoglobin (HbA1c), although many studies were too short to detect a significant change. The studies were also small and very heterogeneous with respect to dose, duration, use of conventional medications, and baseline diabetes control. It appears that duration of use, dosage, and baseline glycemic levels may be important factors influencing the results and deserve further study. Furthermore, the effects on type 2 diabetes are more promising than on type 1 diabetes. In patients with type 1 diabetes, clinical research shows that daily cinnamon intake does not improve fasting blood glucose, HbA1c, insulin sensitivity, or the frequency of hypoglycemic episodes. Another factor is the type of cinnamon used, since many different species are available in products and they may differ in their chemical composition and resulting activities. For example, some studies used water-soluble cinnamon extract rather than the whole spice. Unfortunately, some studies do not specify which cinnamon was used, which makes interpreting the studies difficult. Finally, the use of antidiabetic medications in combination with cinnamon may yield better results. A highly successful early study, conducted in patients on sulfonylureas (a medication that increases insulin secretion), showed significant effects on fasting blood glucose. Indeed, increased insulin secretion, combined with cinnamon's role in reducing insulin resistance, may produce better outcomes.
Posologie
Oral: bark
120 - 6000 mg
12 weeks
powder, dry extract
Effect of cinnamon on glucose and lipid levels in non-insulin-dependent type 2 diabetes
The effect of cassia cinnamon powder in type 2 diabetes mellitus
Cinnamon use in type 2 diabetes: an updated systematic review and meta-analysis
Effect of cinnamon on glucose control and lipid parameters
The effect of cinnamon on A1C among adolescents with type 1 diabetes
Cinnamon extract improves fasting blood glucose and glycosylated hemoglobin level in Chinese patients with type 2 diabetes
Effects of a cinnamon extract on plasma glucose, HbA, and serum lipids in type 2 diabetes mellitus
Cinnamon supplementation does not improve glycemic control in postmenopausal type 2 diabetes patients
Efficacy of cinnamon in patients with type II diabetes mellitus: A randomized controlled clinical trial
Glycated hemoglobin and blood pressure-lowering effect of cinnamon in multi-ethnic Type 2 diabetic patients in the UK: a randomized, placebo-controlled, double-blind clinical trial
Effectiveness of cinnamon for lowering hemoglobin A1C in patients with type 2 diabetes: a randomized, controlled trial
Cinnamon in glycemic control: systematic review and meta-analysis
Dietary cinnamon supplementation and changes in systolic blood pressure in subjects with type 2 diabetes
Digestive disorders ✪✪✪✪✪
Cinnamon bark essential oil and ground cinnamon bark are used in the treatment of dyspeptic conditions, such as mild spasmodic conditions of the gastrointestinal tract, fullness and flatulence, loss of appetite and diarrhea. Although controlled studies are not available, evidence of antispasmodic activity in animal models and a long history of use provide some support for its use in these indications. Cinnamon bark and Chinese cinnamon are approved by the German Commission E for the treatment of loss of appetite and dyspeptic complaints such as mild gastrointestinal spasms, bloating and flatulence. ESCOP indicates that cinnamon is used in dyspeptic conditions such as gastrointestinal spasms, bloating and flatulence, loss of appetite, diarrhea...
Posologie
Oral: bark
500 - 1500 mg
powder, essential oil, dry extract
Metabolic syndrome ✪✪✪✪✪
Results on the efficacy of cinnamon in prediabetic subjects are contradictory. A small clinical study conducted in patients with glucose intolerance shows that taking 6 g of cinnamon powder (C. cassia) twice daily for 12 weeks does not improve fasting blood glucose or insulin sensitivity compared with placebo. However, a water-soluble cinnamon extract (Cinnulin PF 500 mg/day) significantly reduced fasting blood glucose and systolic blood pressure and increased lean body mass, according to a placebo-controlled trial conducted in 22 subjects with prediabetes and metabolic syndrome. The study lasted 12 weeks and also detected small but statistically significant reductions in body fat in the cinnamon-treated group when within-group analyses were performed. Another clinical study in overweight or obese patients with impaired fasting glucose shows that taking a 250 mg dried aqueous extract of cassia cinnamon twice daily for 12 weeks reduced fasting blood glucose by about 12 mg/dL from baseline, but did not affect fasting insulin levels. Another preliminary clinical trial in overweight or obese patients with glucose intolerance found that taking two capsules daily of a specific product (Glycabiane, PiLeJe) containing 228 mg of cassia cinnamon extract, 10 mcg chromium chloride, and 100 mg carnosine per capsule for 4 months reduced fasting blood glucose by 6.5 mg/dL but had no effect on glycated hemoglobin (HbA1c), insulin sensitivity, or body weight compared with placebo.
Posologie
By mouth: bark
500 mg
powder, dry extract
Synergies
Effects of a water-soluble cinnamon extract on body composition and features of the metabolic syndrome in pre-diabetic men and women
Cinnamon supplementation positively affects obesity: A systematic review and dose-response meta-analysis of randomized controlled trials
A Dietary Supplement Containing Cinnamon, Chromium and Carnosine Decreases Fasting Plasma Glucose and Increases Lean Mass in Overweight or Obese Pre-Diabetic Subjects: A Randomized, Placebo-Controlled Trial
Efficacy and safety of cinnamon in type 2 diabetes mellitus and pre-diabetes patients: A meta-analysis and meta-regression
Antioxidant effects of a cinnamon extract in people with impaired fasting glucose who are overweight or obese
Gestational diabetes ✪✪✪✪✪
A randomized, double-blind, placebo-controlled study of 51 women with gestational diabetes found that 6 weeks of treatment with 1 g of cinnamon per day led to a trend toward reduced insulin requirements (53.85% for cinnamon versus 44% for placebo); however, this trend was not statistically significant. The cinnamon used was C. cassia. The researchers suggested that a longer treatment duration might be necessary to achieve better results.
Posologie
By mouth: bark
1000 mg
powder, dry extract
Dysmenorrhea ✪✪✪✪✪
Cinnamon has been traditionally used for gynecological problems in women such as dysmenorrhea, menorrhagia, lactation and labor pains. A small study demonstrated that the use of cinnamon (Cinnamomum Zeylancium) at 3 g per day can significantly reduce the intensity of menstrual pain.
Posologie
Oral: bark
3000 mg
powder
Bacterial infections ✪✪✪✪✪
Cinnamon has been traditionally used for common infections such as bronchial, ENT, urinary or gastrointestinal infections. In Traditional Chinese Medicine (TCM), it is considered to warm the kidneys and strengthen the yang, and it is therefore used for impotence, among other indications.
Posologie
Oral: bark
1500 mg
powder, essential oil, dry extract
Cough ✪✪✪✪✪
Cinnamon has many applications in traditional medicine. It has been used for cough, abdominal cramps and intestinal spasms.
Posologie
Oral: bark
1500 mg
powder, essential oil, dry extract
Warts ✪✪✪✪✪
Cinnamon essential oil, rich in cinnamaldehyde, is traditionally used to treat warts, thanks to its caustic dermal properties that act directly on the lesion. To be used pure or diluted in a vegetable oil.
Posologie
Topical use: bark
3 drops
essential oil
Properties
Antibacterial
Several in vitro studies have identified broad-spectrum antibacterial and fungicidal effects for both cinnamon species. These effects have been mainly attributed to the cinnamaldehyde, although other constituents such as eugenol, caryophyllene and 1,8-cineole also exhibit antimicrobial properties. The species C. verum has demonstrated activity against a wide range of bacteria and fungi, including Bacillus subtilis, Escherichia coli, Saccharomyces cerevisiae, Candida albicans, Listeria monocytogenes and Salmonella enterica. Cinnamon extracts were found to be superior to two other antifungals (garlic and calendula) in an in vitro study, and were recommended as an effective herbal treatment for candidiasis. In vitro, cinnamon extracts significantly inhibit Helicobacter pylori with an effect equal to or greater than that of commonly used antibiotics. Similarly, cinnamon bark essential oil has been shown in vitro to inhibit pathogenic respiratory tract strains (S. pneumoniae, S. pyogenes, S. aureus, H. influenzae…).
Usages associés
Hypoglycemic
Procyanidin oligomers of types A and B present in various cassia cinnamon extracts have been identified as having hypoglycemic activity and may improve insulin sensitivity in the treatment of rats with induced type 2 diabetes. Polyphenolic polymers such as hydroxy-chalcone found in cassia cinnamon appear to potentiate the action of insulin. These compounds appear to increase phosphorylation of the insulin receptor, which enhances insulin sensitivity. Increased insulin sensitivity can improve glycemic control and lipid levels. Cinnamon extracts also appear to activate glycogen synthase and increase glucose uptake. Animal and in vitro studies suggest that cassia cinnamon has a greater insulin-stimulating effect than Ceylon cinnamon. Research conducted in healthy humans shows that cassia cinnamon improves short-term glycemic control and insulin sensitivity; however, clinical trials in diabetic patients have produced conflicting results.
Usages associés
Digestive effect
Cinnamon is traditionally used to aid digestion and as a carminative, in combination with other herbs, for flatulence, bloating, mild gastrointestinal spasms, and as an appetite stimulant.
Usages associés
Antifungal
The bark of Cinnamomum cassia demonstrated strong antifungal activity against strains of Candida albicans. Among the different extracts tested, the chloroform extract proved the most effective, with inhibition zones reaching up to 60 mm and minimum inhibitory concentrations (MICs) of 0.10 µg/ml for Candida albicans ATCC 10231. These results even surpass those of amphotericin B, a reference antifungal. The bioactive compounds identified in the bark include terpenes, flavonoids and alkaloids, which are responsible for these remarkable antifungal effects.
Uricosuric effect
The cinnamon bark extract was studied in combination with a Chrysanthemum indicum flower extract. The combination reduced serum uric acid levels in rats and promoted the excretion of uric acid in the urine. This combination also inhibits xanthine oxidase activity, hepatic uric acid production and cellular uptake of uric acid in vitro.
Cardiovascular
Data from animal experiments suggest that cinnamon may have a beneficial effect on lipid metabolism control. Animal studies have shown that treatment with a water-soluble cinnamon extract induces a decrease in blood glucose and postprandial serum triglycerides.
Usages associés
Safe dosage
Adults 18 years and older: 500 mg - 4000 mg
- infusion: 2 to 4 g of Ceylon cinnamon bark per cup of boiling water, steep for 10 minutes, to drink 2 to 3 times per day - dried bark: 1.5 to 4 g per day - powder: 0.5 to 1.5 g per day; - essential oil: 0.005 to 0.2 g per day; - fluid extract (1:1 in 70% alcohol) 2-4 ml
Interactions
Médicaments
Antidiabetic: low interaction
Cassia cinnamon may lower blood glucose levels and have additive effects in patients treated with antidiabetic agents. Dose adjustments of diabetes medications may be necessary.
Antiplatelet agents/Anticoagulant: low interaction
In vitro, cinnamaldehyde, a major compound of Cinnamomi Cortex, inhibits the release of arachidonic acid and thus the formation of thromboxane B2. It can thereby reduce platelet aggregation. Theoretically, concomitant use of C. cassia with anticoagulants/antiplatelet agents could increase the risk of bleeding
Precautions
Liver disorders: avoid
Coumarins taken orally at high doses are known to cause liver damage in rodents, and isolated similar incidents of hepatotoxicity have been observed in humans. C. cassia contains high amounts of coumarin (up to 87,000 mg/kg) compared to C. verum or C. burnanii. Warning from several European health agencies regarding the consumption of large amounts of cassia due to its high coumarin content. Hepatotoxic doses of coumarin in therapy: 50–7000 mg/day. (Tolerable daily intake of coumarins from the diet: 0–0.1 mg/kg body weight) The French agency recommends not exceeding 0.1 mg/kg/day of essential oil (i.e., 3 g of Chinese cinnamon).
Breastfeeding women: avoid
There is not enough reliable information available on the safety of cassia cinnamon when used in medicinal amounts during breastfeeding.
Children up to 18 years: use with caution
Half the adult dose.
Contraindications
Pregnant woman: prohibited
C. cassia or C. zeylanicum/verum should not be used during pregnancy; however, usual dietary intakes are probably safe. Currently, evidence of teratogenicity from animal studies is contradictory.
