Cinnamon

Medically reviewed by Prof. Giorgi Pkhakadze, MD, MPH, PhD — GMJ Editorial Board

What is Cinnamon?

Cinnamon is a popular spice derived from the inner bark of trees belonging to the genus Cinnamomum. The most common varieties used in supplements are Ceylon cinnamon (Cinnamomum verum) and Cassia cinnamon (Cinnamomum cassia). As an herbal extract category supplement, cinnamon has been used for thousands of years both as a culinary spice and traditional medicine. The bark is harvested, dried, and naturally curls into quill-like rolls. For supplements, cinnamon is typically processed into powder form or concentrated extracts containing active compounds like cinnamaldehyde, cinnamic acid, and procyanidin polymers.

Unlike essential nutrients, cinnamon has no established Recommended Daily Allowance (RDA) or Upper Limit (UL) from health authorities. However, its bioactive compounds have attracted significant research interest for potential therapeutic applications, particularly in metabolic health and blood sugar management.

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Health benefits & uses

Blood sugar management (Moderate evidence): Multiple studies suggest cinnamon may help improve glucose metabolism and insulin sensitivity. A systematic review of randomized controlled trials found that cinnamon supplementation can modestly reduce fasting blood glucose levels in people with type 2 diabetes, though effects vary between studies.

Cardiovascular health (Limited evidence): Some research indicates cinnamon may help reduce total cholesterol, LDL cholesterol, and triglycerides. However, results are inconsistent across studies, and more research is needed to establish definitive cardiovascular benefits.

Anti-inflammatory effects (Limited evidence): Laboratory studies show cinnamon extracts possess anti-inflammatory properties, potentially due to compounds like cinnamaldehyde. Human studies demonstrating clinically significant anti-inflammatory effects remain limited.

Antioxidant activity (Moderate evidence): Cinnamon ranks high among spices for antioxidant content, with polyphenolic compounds that may help protect cells from oxidative stress. However, translating these laboratory findings to meaningful health outcomes in humans requires further investigation.

How it works

Cinnamon’s potential health effects stem from several bioactive compounds. Cinnamaldehyde, responsible for cinnamon’s characteristic flavor and aroma, appears to enhance insulin signaling pathways and glucose uptake by cells. Procyanidin type-A polymers may mimic insulin activity and improve glucose metabolism.

The spice’s antioxidant properties come primarily from polyphenolic compounds that neutralize free radicals and may reduce oxidative stress. Some research suggests these compounds can influence inflammatory pathways, potentially explaining cinnamon’s traditional use for various health conditions.

Cinnamon may also affect digestive processes, potentially slowing gastric emptying and reducing post-meal blood sugar spikes. However, the exact mechanisms and their clinical significance continue to be studied.

Dosage

Typical adult dosages for cinnamon supplements range from 1-6 grams daily, often divided into multiple doses. Most clinical studies have used 1-3 grams daily for blood sugar management. However, optimal dosing remains unclear due to variations in study designs and cinnamon preparations.

Since no official RDA or UL exists for cinnamon, and individual responses can vary significantly, consultation with a healthcare provider is essential before starting supplementation. This is particularly important for people with diabetes or those taking medications, as cinnamon may affect blood sugar levels.

Ceylon cinnamon is generally preferred for supplementation due to lower coumarin content compared to Cassia varieties, making it safer for long-term use.

Food sources

Cinnamon is widely available as a culinary spice and can be incorporated into the diet through various foods and beverages. Common sources include:

• Ground cinnamon powder added to oatmeal, yogurt, or smoothies
• Cinnamon sticks used in teas, coffee, or cooking
• Cinnamon-spiced foods like baked goods and desserts
• Traditional beverages like chai tea or golden milk
• Savory dishes in Mediterranean, Middle Eastern, and Asian cuisines

While culinary amounts provide beneficial compounds, therapeutic dosages typically require concentrated supplements to achieve levels used in clinical studies.

Safety & side effects

Cinnamon is generally safe for most people when consumed in typical food amounts. However, supplements providing higher doses may cause side effects in some individuals, including mouth sores, digestive upset, or allergic reactions.

Cassia cinnamon contains significant amounts of coumarin, a compound that may cause liver damage with prolonged high-dose use. Ceylon cinnamon contains much lower coumarin levels and is considered safer for supplementation.

Common side effects from high-dose cinnamon supplementation may include gastrointestinal irritation, mouth ulcers, and increased heart rate. Some people may experience allergic reactions, particularly those sensitive to cinnamon or related plants.

Interactions

Cinnamon may interact with several medications and supplements:

Diabetes medications: Cinnamon may enhance blood sugar-lowering effects of insulin, metformin, and other antidiabetic drugs, potentially causing hypoglycemia.

Blood thinners: High-coumarin Cassia cinnamon may enhance anticoagulant effects of warfarin and similar medications.

Liver medications: Coumarin-containing cinnamon varieties may interact with drugs processed by the liver.

Always inform healthcare providers about cinnamon supplementation, especially when taking prescription medications.

Who should be cautious

Certain individuals should exercise caution with cinnamon supplements:

• People with diabetes taking blood sugar-lowering medications
• Individuals with liver disease or taking hepatotoxic medications
• Those on blood-thinning medications
• Pregnant or breastfeeding women (safety data limited)
• People with known allergies to cinnamon or related plants
• Individuals scheduled for surgery (may affect blood clotting)

Frequently asked questions

What’s the difference between Ceylon and Cassia cinnamon?

Ceylon cinnamon (Cinnamomum verum) is considered “true” cinnamon and contains very low levels of coumarin, making it safer for long-term supplementation. Cassia cinnamon (Cinnamomum cassia) is more common and less expensive but contains higher coumarin levels, which may pose liver risks with prolonged high-dose use.

Can cinnamon replace diabetes medication?

No, cinnamon should never replace prescribed diabetes medications. While research suggests it may provide modest blood sugar benefits, it cannot substitute for proven medical treatments. Always consult your healthcare provider before making any changes to diabetes management.

How long does it take to see effects from cinnamon supplements?

Studies suggest potential blood sugar effects may be observed within 1-2 weeks of consistent use, though individual responses vary. However, most clinical trials showing benefits used supplementation for several weeks to months.

Is cinnamon safe during pregnancy?

While culinary amounts of cinnamon are generally considered safe during pregnancy, the safety of therapeutic supplement doses hasn’t been well-studied in pregnant women. Pregnant women should consult their healthcare provider before using cinnamon supplements.

Can I take cinnamon supplements with other herbs?

Cinnamon may be combined with other herbs, but potential interactions should be considered. Particularly avoid combining with other blood sugar-lowering herbs without medical supervision, as this may cause hypoglycemia. Always discuss supplement combinations with a healthcare provider.