This article is well researched, footnoted, long, detailed, and makes many excellent points about agave and your health. I've been reluctant to use it, not only from the cost, but I got rid of my craving for "sweet" a long time ago. Then there's my natural skepticism over anything so hyped. Still, many people use agave thinking it's a "health food" when, in fact, it apparently isn't.
Below are some quick edits from the much longer article (and a highly recommended read) here.
... Most agave syrup has a higher fructose content than any commercial sweetener -- ranging from 55 to 97 percent, depending on the brand, which is FAR HIGHER than high fructose corn syrup (HFCS), which averages 55 percent. This makes agave actually WORSE than HFCS.
... In addition to insulin resistance, your risk of liver damage increases, along with triglycerides and a whole host of other health problems, as discussed in this CBC News video about the newly discovered dangers of high fructose corn syrup. The study discussed in this news report is about HFCS, however, it's well worth remembering that agave contains MORE fructose than HFCS, and in all likelihood, it's the FRUCTOSE that is causing these severe liver problems.
... though processing methods can differ among manufacturers, most commercially available agave is converted into fructose-rich syrup using genetically modified enzymes and a chemically intensive process involving caustic acids, clarifiers, and filtration chemicals...
...In case you doubt the influence of marketing in setting trends and consumer buying habits, look at these statistics... New agave products more than tripled in number between 2003 and 2007, from 56 to 176. Agave syrup is now appearing in products such as energy bars, cereals and organic ice creams. Revenues for the category "other liquid sweeteners," which includes agave, rose to more than $10.3 million in 2007, which was a 50 percent jump from 2006.
...It's important for you and your family's health to remember that agave syrup is neither healthy nor natural. As reported by Dr. Ingrid Kohlstadt, a fellow of the American College of Nutrition and an associate faculty member at Johns Hopkins School of Public Health:
"Agave is almost all fructose, a highly processed sugar with great marketing..."