Q I read your article last year on cinnamon and high blood sugar ( “Cinnamon Reduces Blood Sugar in Diabetic Patients,” July 2006). However, I am unable to eat nightshades, and I understand cinnamon is a nightshade. Do you have any thoughts on this?

DAVID, Chapel Hill, NC

A Cinnamon belongs to the family Lauraceae and is not a nightshade. Nightshades are members of the family of flowering plants known as Solanaceae, which includes jimsonweed, henbane, mandrake, belladonna, capsicums (paprika, chili peppers, etc.), eggplant, potato, tomato, tobacco, and petunia.

The fact that herbs and spices are natural does not mean they are safe, especially in large quantities. The fat-soluble portion of cinnamon, e.g., contains coumarin, an anticoagulant that’s potentially harmful in large amounts, as well as cinnamaldehyde, which is potentially allergenic. So it’s fortunate that the blood-sugar-lowering procyanidins (type A) that are described in the article you mentioned (and in other articles in Life Enhancement†) are found in the water-soluble portion of cinnamon powder. By extracting and using only that portion, the risk from the fat-soluble compounds is eliminated.