Two jars can both say “cinnamon” and still contain noticeably different spices. Ceylon cinnamon and cassia share a warm, sweet aroma, but they come from different species and differ in flavor, bark structure, and—most importantly for frequent use—the amount of coumarin they contain.
If you dust a little cinnamon over oatmeal once in a while, the distinction is usually not a major practical issue. If cinnamon is a daily habit measured in teaspoons rather than pinches, knowing which type is in the jar becomes much more useful.
They are related spices, not two names for the same product
Ceylon cinnamon is mainly Cinnamomum verum, historically associated with Sri Lanka. Cassia refers to related cinnamon species, including Cinnamomum cassia or C. aromaticum. In the United States, cassia is the type commonly sold simply as “cinnamon,” while Ceylon is more often labeled specifically.
The flavor difference is real too. Ceylon tends to be lighter, more floral, and slightly citrusy; cassia is usually bolder, sweeter, and hotter. That does not make cassia “fake cinnamon.” It makes the two useful for somewhat different culinary preferences.
Coumarin is the difference that matters for heavy daily use
Coumarin is a naturally occurring plant compound. Germany’s Federal Institute for Risk Assessment (BfR) uses a tolerable daily intake of 0.1 mg of coumarin per kilogram of body weight per day. For a 132-pound (60-kg) adult, that works out to 6 mg per day.
BfR reports an average of about 3,000 mg of coumarin per kilogram of cassia cinnamon, or roughly 3 mg per gram, with some samples reaching close to 10,000 mg/kg. At the average concentration, about 2 g of cassia would provide around 6 mg—the tolerable daily intake for that 60-kg adult. Ceylon cinnamon, by contrast, contains only low or trace amounts.
That does not turn 2 g into a sharp line between “safe” and “dangerous.” A tolerable daily intake is designed around repeated lifetime exposure, and an occasional day above it is not the same thing as poisoning. The useful distinction is between a small culinary amount now and then and gram-level cassia use every day for months.
Cinnamon sticks are easier to identify than cinnamon powder
Ceylon sticks are made of many thin, papery layers rolled together. Cassia bark is much thicker and harder, usually forming one or only a few curls. Side by side, the difference can be striking.
Once the spice is ground, appearance is a poor test. BfR notes that cinnamon powders are difficult to distinguish visually. If you specifically want Ceylon for its low coumarin content, look for “Ceylon” or Cinnamomum verum on the label rather than relying on color.
Which one should you buy?
For a recipe that benefits from a bold cinnamon punch, cassia may be exactly right. For custards, fruit, tea, or other preparations where a softer aroma is welcome, Ceylon can be appealing. Flavor is a preference; the coumarin question is mostly about dose and frequency.
The U.S. National Center for Complementary and Integrative Health says cinnamon in amounts commonly used in foods is generally considered safe. It also notes that prolonged use of large amounts of cassia can be a concern for sensitive people, particularly those with liver disease.
A spice does not need to become a supplement
Ceylon’s lower coumarin content is not a reason to start taking spoonfuls of cinnamon for a promised health effect. Current evidence does not clearly support cinnamon as a treatment for a health condition, and study results on metabolic outcomes have not been consistent enough to make large daily doses a sensible default.
Use cinnamon first as food. For occasional small amounts, let flavor and price decide. For a daily habit measured in grams, Ceylon sharply reduces coumarin exposure and is the more practical choice for long-term use.
Sources
- BfR — FAQ on coumarin in cinnamon and other foods — Tolerable daily intake for coumarin, cassia concentrations, Ceylon comparison, and guidance for frequent cinnamon users.
- NCCIH — Cinnamon — Cinnamon species, culinary safety, coumarin concerns, and current evidence on health claims.