One of these three spices has real human-trial evidence behind it. The other two only have animal data — and the researchers who reviewed it say so explicitly. Here's the difference, spice by spice.

Most "cinnamon" on shelves is Cassia, not true Ceylon. Here's how to tell them apart by bark, color and taste, why coumarin is the difference that matters, and how to check what's actually in your pouch.