Up until recently, I've been happily buying saigon cinnamon to sprinkle on oatmeal and toast (and sometimes my coffee). That is, until I heard that out of all the cinnamon varieties out there, saigon contained by far and away the highest levels of the liver-damaging substance coumarin. Yikes.

The type of cinnamon with the least coumarin is known as ceylon—also known as "true cinnamon." Its flavor is more delicate but much sweeter than other varieties. The best ceylon I've found on Amazon is this organic ground cinnamon from Frontier Natural Products.

It's about $5 for a 1.76-ounce bottle (or $21 for a 1-pound bag), which isn't the cheapest deal around but probably worth the cost in the long run for those of us who consume a lot of cinnamon.

If you prefer to grind the stuff fresh at home, Indus Organics sells various-sized packs of ceylon cinnamon sticks that work nicely—3oz ($12), 8oz ($20), and 16oz ($35).