Well, it was too good to be true. Just as Agave nectar is hitting the shelves en masse, we're finding out that although it doesn't mess with insulin resistance, it's not so innocent. It turns out that agave is being produced in such a way that it's about 90% fructose. Fructose is a type of sugar that has to be converted to glucose by the liver. People that are consuming agave on a regular basis are ending up with elevated triglycerides (part of a cholesterol panel), and some are experiencing high liver enzymes.
Wondering what to do if you've been using agave? Switch to molasses, honey, or maple syrup---and even then, use minimally. These sweeteners have more anti-oxidants in them to help your body process the sugars, and they're lower in fructose (higher in glucose, and easier for the body in general).