SRI LANKA

Sri Lanka grows the original cinnamon, pale bark peeled from one tree.
Most of the world buys a cheaper cousin your liver would rather you skip.

True cinnamon (Ceylon)  ·  Cinnamomum verum  ·  Mechanism: low coumarin

True cinnamon comes from Cinnamomum verum, a tree native to Sri Lanka, where the island still grows the large majority of the world's supply. The spice itself is the tree's thin inner bark, peeled off in long strips and dried until it curls into fragile, papery quills the color of pale tan, light enough to crumble between your fingers.

This is the cinnamon that European powers once fought wars over, the spice that pulled Portuguese, Dutch, and British traders to the island for centuries. It is delicate and faintly sweet, closer to a perfume than to the hot, brassy, almost harsh spice most Americans actually picture.

What most of the world actually calls cinnamon is usually a different tree entirely, cassia, grown mainly in China, Indonesia, and Vietnam. Cassia is cheaper, darker, and harder, a single thick curl rather than a bundle of thin papery layers, and it is the one that dominates supermarket shelves and spice jars.

The two are sold under the same single word, cinnamon, as if they were freely interchangeable in every way. They are not, and the difference between them is not only a matter of flavor but of what your liver has to process.

The gap that matters most is a natural compound called coumarin. Cassia is loaded with it, while true Ceylon cinnamon carries only a trace, and coumarin in quantity can stress and inflame the liver over time, which is exactly why European food-safety agencies set a strict daily limit on how much is reasonable to eat in a day.

The numbers are genuinely stark. About a single teaspoon of cassia can bring a smaller adult right to that daily coumarin limit, while you would have to eat many spoonfuls of Ceylon to get anywhere near it, which is the entire case for knowing which of the two sits in your cabinet.

Sold under one word, cinnamon, they are two different trees.

The irony is that the health claim people actually chase, cinnamon for blood sugar, rests on modest and inconsistent evidence, and most of those trials happened to use cassia, the riskier of the two. The honest read is that cinnamon may nudge fasting glucose a little, that Ceylon is the clearly safer bark for anyone using it every day, and that neither version is a substitute for the real work of managing blood sugar, from food to movement to medication.

The how-to

The single most useful move here is reading the species on the label.

If you eat cinnamon most days, buy true Ceylon cinnamon, which names Cinnamomum verum on the label, sold at spice shops, South Asian grocers, and online for a few dollars more than the generic kind. In stick form Ceylon is pale, brittle, and rolled into many thin papery layers, while cassia is dark, hard, and a single tight curl.
For an occasional sprinkle on toast or coffee, ordinary cassia is fine and the coumarin is not a real concern. The switch matters if you take cinnamon in large or daily doses, in capsules, or by the spoonful stirred into food every morning.
Do not expect cinnamon of either kind to control blood sugar on its own, since the effect is small and inconsistent. Treat Ceylon as the safer choice for a daily habit, not as a reason to start one for glucose.
Go easy on high-dose cassia if you have liver disease or take a blood thinner such as warfarin, since coumarin stresses the liver and can interact. And if you use cinnamon alongside diabetes medication, keep an eye on your glucose, because any lowering effect can stack with the drugs.

Tomorrow: China and tai chi
the slow practice with real trial evidence for balance, and why that matters more with age.

See you then.