Cassia (Cinnamomum cassia)

Cassia (Cinnamomum cassia) is a traditional Chinese medicinal herb whose primary bioactive compound, cinnamaldehyde, modulates glucose metabolism by enhancing insulin receptor signaling and inhibiting alpha-glucosidase. It also contains coumarin and procyanidins that contribute to its antioxidant, antimicrobial, and circulatory-warming effects recognized in TCM.

Origin & History

Cassia (Cinnamomum cassia) is an evergreen tree native to southern China and parts of Southeast Asia. Its inner bark is harvested, dried into quills, and used as a spice or medicinal material. Essential oils are extracted via steam distillation, while solvent methods or water decoction yield extracts.

Historical & Cultural Context

In Traditional Chinese Medicine, C. cassia bark, known as Rou Gui, has been used for over 2,000 years. It is employed to treat respiratory and digestive disorders, warm the interior, tonify kidney yang, and promote blood circulation.

Health Benefits

• Traditionally used to treat respiratory and digestive disorders, based on historical use [2][3]. • Possesses antioxidant properties as noted in preclinical studies [2][3]. • Exhibits antimicrobial effects, particularly antifungal activity in vitro against Candida species [1]. • Used to warm the interior and tonify kidney yang in TCM practices [2][3]. • Promotes blood circulation according to traditional applications [2][3].

How It Works

Cinnamaldehyde, the principal bioactive in Cassia bark, activates insulin receptor autophosphorylation and upregulates GLUT-4 translocation, improving cellular glucose uptake independent of insulin secretion. Procyanidins inhibit alpha-glucosidase and alpha-amylase enzymes in the small intestine, slowing post-meal glucose absorption. Coumarin and cinnamaldehyde also exhibit NF-κB pathway suppression, reducing pro-inflammatory cytokine expression including TNF-α and IL-6.

Scientific Research

No specific human clinical trials, RCTs, or meta-analyses for Cinnamomum cassia are available. The current research is limited to in vitro studies and reviews noting traditional uses and preclinical bioactivities, with no PubMed PMIDs provided.

Clinical Summary

A meta-analysis of 10 randomized controlled trials (n=543) found Cassia supplementation reduced fasting blood glucose by approximately 24 mg/dL and HbA1c by 0.27% in type 2 diabetic patients, though effect sizes varied considerably across studies. A 2003 RCT by Khan et al. (n=60) showed 1–6 g/day of Cassia reduced fasting glucose by 18–29% over 40 days. Antimicrobial evidence is largely in vitro, showing MIC values of 0.5–2 mg/mL against Candida albicans, with no large human trials confirming clinical antifungal efficacy. Overall evidence for glycemic benefits is moderate but limited by short trial durations, heterogeneous populations, and high coumarin content raising safety concerns in long-term use.

Nutritional Profile

Cassia (Cinnamomum cassia) is primarily used as a spice and medicinal herb rather than a macronutrient source. Per 100g of ground cassia bark: Calories ~247 kcal, Carbohydrates ~80.6g (of which dietary fiber ~53.1g, representing the dominant macronutrient fraction), Protein ~3.99g, Total Fat ~1.24g (including small amounts of saturated, monounsaturated, and polyunsaturated fatty acids). Moisture content is low (~10.6g) in dried form. Key Micronutrients per 100g: Calcium ~1228mg (notably high, though bioavailability is limited due to oxalate binding), Iron ~8.32mg, Manganese ~17.5mg (exceptionally high, exceeding daily reference intake), Magnesium ~60mg, Potassium ~431mg, Phosphorus ~64mg, Zinc ~1.83mg, Vitamin K ~31.2mcg, Vitamin A ~15mcg RAE, small amounts of B vitamins including niacin (~1.33mg) and riboflavin (~0.04mg). Bioactive Compounds: Cinnamaldehyde (primary volatile compound, comprising 75–90% of essential oil by mass) is the principal bioactive constituent responsible for antimicrobial and antioxidant effects; Coumarin is present at significantly higher concentrations in Cassia (~1–12mg/g dry weight) compared to Ceylon cinnamon (<0.017mg/g), raising hepatotoxicity concerns at high intake levels — the European Food Safety Authority has set a tolerable daily intake of 0.1mg/kg body weight. Other bioactives include cinnamyl acetate, eugenol (~trace to 5% of essential oil), trans-cinnamic acid, procyanidin polyphenols (particularly type-A and type-B oligomers), and cinnamic alcohol. Polyphenol content is estimated at ~8000mg per 100g, contributing to its high ORAC antioxidant value (~267,536 µmol TE/100g). Bioavailability notes: Cinnamaldehyde is rapidly absorbed in the gastrointestinal tract but undergoes first-pass metabolism to cinnamic acid; coumarin is well-absorbed orally and accumulates with repeated exposure; mineral bioavailability is reduced by the high fiber and oxalate content; polyphenols have variable absorption estimated at 5–20% depending on gut microbiota composition.

Preparation & Dosage

No clinically studied dosage ranges for extracts, powder, or standardized forms are reported due to the absence of human trials. Standardized extracts often target cinnamaldehyde content (42-73%). Consult a healthcare provider before starting any new supplement.

Synergy & Pairings

Ginger, Turmeric, Cardamom, Black Pepper, Clove

Safety & Interactions

Cassia contains high levels of coumarin (1–12 mg/g), which can cause hepatotoxicity with chronic daily intake exceeding the European Food Safety Authority's tolerable daily intake of 0.1 mg/kg body weight; Ceylon cinnamon (C. verum) contains far less coumarin and is safer for regular use. Cassia may potentiate hypoglycemic drugs including metformin and insulin, increasing risk of hypoglycemia. It may also interact with anticoagulants like warfarin due to coumarin content, potentially altering INR values. Cassia is traditionally contraindicated in pregnancy at medicinal doses due to uterotonic effects, and individuals with liver disease should avoid supplemental use.