Over the last couple of years I’ve watched the food community rave about the wonders of agave. This nectar from a succulent plant joins stevia, corn syrup and even good old fashioned honey in an array of “natural” alternatives to cane sugar. So is one form of sweetener any better than the other?
While you might think the body metabolises all sweeteners in the same way, high levels of fructose (such as in agave nectar and corn syrup) adds a few twists to this biological activity.
Contrary to what most of us imagine, agave is not tapped from the plant and eaten in an unprocessed state. Agave nectar is created from a starchy substance that is heated and refined to create a sweet liquid. This is where fructose enters the picture. Agave nectar processed in this manner bears many nutritional similarities to High Fructose Corn Syrup (HFCS), a liquid sugar replacement derived from corn favoured by the bulk food and confectionary industry due to its low cost. The scientific reasons why we metabolise fructose differently from a simple sugar like glucose are complex. A bit like there being “good” fats and “bad” fats, or more appropriately fats that benefit the body compared to those that tend to harm it, there are different kinds of sugars. Glucose (which I am in no way suggesting is some kind of health food) is a disaccharide while fructose in a monosaccharide dictating that the body metabolise the two substances slightly differently. At this point the issue gets more complex because the problem is not solely about fructose per se but the ratio between glucose and fructose in a given food. HFCS, for example, tends to range from 42-90% fructose (though often it is quoted as 55% fructose to 45% glucose) and the greater the quantity of fructose to simple glucose the more worrying the health implications.
An ABC radio Health Report interview with Robert Lustig (Professor of Paediatric Endocrinology at the University of California, San Francisco) explains the connection between high fructose foods and not just obesity and insulin resistance diabetes but liver disease as well. Lustig goes as far as calling fructose as an hepato-toxin (something that poisons the liver), which if we extend the logic to a product like agave nectar suggests that no matter how “organic” or “natural” the sweetener is, or how low the glycaemic index, this does not deserve the moniker of a “health food”.
Take home message
Sugar in any form tends to burden our body with extra, unnecessary calories. Don’t kid yourself that one form is better for you than another. Have a healthy scepticism for new “wonder foods” (and “super foods”) – if it sounds too good to be true, it probably is.
Food Renegade’s rethink on the agave conundrum.
A good rundown on different types of sugars/sweeteners from Melissa at Gluten Free for Good.
The biological issues regarding fructose digestion are not to be confused with Fructose Malabsorption Intolerance (FMI) is an increasingly diagnosed condition caused by an impaired ability to digest fructose. FMI causes food intolerance/irritable bowel type symptoms and is managed by dietary changes. While fructose is potentially hepato-toxic to everyone, those with FMI have additional issues.
This article was first published in the Health Trip eNewsletter, January 2010. The newsletter is free, just click on the link to subscribe.