When Agave nectar first burst on the scene as a healthier sweetener, it appeared to be superior to sugar and other dietary sweeteners like high fructose corn syrup. It was easy to imagine that for thousands of years Native Americans had been tapping the sap of the agave plant, using its sweet juice, perhaps boiling it down to a honey-like syrup.
According to Wikipedia’s article on agave, there is a nectar called aguamiel that can be collected by cutting underneath the flower spike or extracted from the flower like it is from sugarcane. It is collected from the maguey agave and sold as a sports drink in Mexico, often with added chili pepper. This has nothing to do with the commercial agave nectar sold by any manufacturer.
The agave rootstalk or piña is, like chicory and Jerusalem artichokes, full of a slightly sweet mostly indigestible polysaccharide called inulin. There are likely other starches in the tough rootstalk since the amount of inulin is estimated from a minor constituent to virtually all inulin. This root is treated with enzymes, according to the patent below from Aspergillis niger mold but possibly from other sources depending on the maker, and is converted through a complex process to fructose.
It is worth pointing out that fructose is not the identical to the fruit in
sugar, levulose which is a levorotatory D-form of fructose combined with a number of compounds found in fruit. Most of the fructose in fruit is in the form of L-fructose or levulose; the fructose in HFCS is a different isomer, D-fructose. You cannot tap a corn stalk to get fructose, it requires conversion via heat and enzymes to break it down. Refined fructose is similar to the natural levulose- the levorotatory D form of the base chemical is identical-, but refined fructose lacks amino acids, vitamins, minerals, pectin and fiber and is processed in the liver instead of the intestines. (It is not accurate however to say that levulose to fructose is as butter is to margarine. A better comparison is molasses to simple sugar syrup.)
Agave nectar consists primarily of fructose and glucose. One brand claims 92% fructose and 8% glucose while another shows 56% fructose and 20% glucose. 76% of glucose burns off and 24 % of it goes into the liver where most of it is stored as glycogen and the rest powers mitochondria for energy. Maybe a half a calorie goes through the TCA cycle which will turn into VLDL cholesterol, used to store fat. 72% of fructose goes into the liver. The breakdown products of this fructose in the liver is far more pernicious, including uric acid which causes gout and hypertension, but more importantly high levels of VLDL and five times as much fat formation (de novo lipogenesis .) It also causes liver insulin resistance and turns off the leptin that tells your brain you have had enough food. Research indicates that free refined fructose interferes with the heart’s use of key minerals like magnesium, copper, and chromium and fructose is known to increase fat, avoid triggering the appetite suppressant leptin and to worsen diabetes although it may not trigger insulin.
The glycemic index or glycemic load of fructose (and agave nectar) is misleading when it comes to deciding what sweetener is better. If you want something that is healthy for diabetics and sweet, use stevia, Aztec sweet herb, licorice or lo han guo which don’t add calories but have a natural sweetness. The glycemic index merely shows how much 100 g of a food will raise blood glucose. Glucose triggers insulin concentrations in the central nervous system which have a direct inhibitory effect on food intake—when insulin secretions increase, food consumption declines. Fructose doesn’t raise blood sugar nor does it trigger insulin, but it increases fat storage, raises triglycerides and interferes with leptin which regulates appetite so that you never feel full.
Fructose and glucose are both bad for you and sources of pure sugars, even the lower density sugars like rice syrup and agave nectar are harmful. I doubt that they are better than the equivalent sweetening power of molasses, which has more minerals. But a dilute thick syrup may be easier to control, especially over pancakes, and adds less taste than molasses.
The “agave nectar wars” started with an article on the Weston A. Price Foundation website on sweeteners that described a process used by one manufacturer of agave nectar, which used GMO, cooked the syrup and produced a higher fructose syrup than some other companies. They used caustic acids, clarifiers, filtration chemicals and the like which are not necessarily universal :
The process by which agave glucose and inulin are converted into “nectar” is similar to the process by which corn starch is converted into HFCS.35 The agave starch is subject to an enzymatic and chemical process that converts the starch into a fructose-rich syrup—anywhere from 70 percent fructose and higher according to the agave nectar chemical profiles posted on agave nectar websites
Agave syrup is a man-made sweetener which has been through a complicated chemical refining process of enzymatic digestion that converts the starch and fiber into the unbound, manmade chemical fructose. While high fructose agave syrup won’t spike your blood glucose levels [as HFCS is reported to do], the fructose in it may cause mineral depletion, liver inflammation, hardening of the arteries, insulin resistance leading to diabetes, high blood pressure, cardiovascular disease and obesity.
The article went on to compare the results of converting the starch to HFCS using GMO enzymes and heat. Now the bottler of Madhava Agave Nectar objects to the WAP article, pointing out that Nekutli, which produces the agave used by Madhava uses a different species of agave than IIDEA, that their extra water is removed by vacuum instead of boiling (although that process also involves heat up to 118 degrees), that their enzymes are not GMO, and alleging that there is no starch in agave or at least Agave salmiana and pointing out that the information on Agave nectar was based on a 90% fructose syrup by a different manufacturer. However he undercuts his argument by not comparing the constituents of the blue agave (A. tequiliana) to A. salmiana and using a generic Wikipedia article on fructans to allege that there is no starch, instead of an analysis of the agave piña. And while technically a fructan isn’t a starch, he is splitting hairs when he claims that cooking or converting inulin and other constituents to fructose and glucose from an indigestible polysaccharide is significantly different from doing the same to corn stalks.
There are at least six species of agave used in making agave nectar according to the somewhat inaccurate Wikipedia article. (It’s description of obtaining aguamiel from A. salmiana contradicts that of the manufacturer and is likely possible with most species) The six species are Blue Agave (Agave tequilana), Salmiana Agave (Agave salmiana), Green Agave, (Agave viridissima) Grey Agave (Agave grisea), Thorny Agave, and Rainbow Agave. Agave lechuguilla is used in Mexico.
Wikipedia describes the harvest of agave:
Harvesting the agave plant remains a manual effort, unchanged by modern farming technologies, and stretching back hundreds of years. The agave is planted, tended, and harvested by hand. The men who harvest it, the “jimadores“, possess generations of knowledge about the plants and the ways in which they need to be harvested. The jimadores must be able to work swiftly in the tight rows, pull out the hijuelos (Agave offspring) without damaging the mother plant, clear the piñas (Spanish for pineapples), and decide when each plant is ready to be harvested . Too soon and there are not enough sugars, too late and the plant will have used its sugars to grow a quiote (20–40 foot high stem), with seeds on the top that are then scattered by the wind. The piñas, weighing 40 to 70 pounds, are cut away with a special knife called a coa.  They are then shredded, their juices pressed out and put into fermentation tanks…
The juices must be reduced by mechanical evaporation or cooking so as not to ferment. Both processes involve heat, but the vacuum evaporation uses heat up to 118 degrees. There are basically four ways to then break down the concentrated juice to sweetener: cooking, chemical processing, fermentation by the mold Aspergillus niger or enzymatically breaking it down. (Enzymes are chemicals, although certain manufacturers claim otherwise.) Different brands use different methods. In the Weston A. Price article there were also chemicals used in refining and clarifying the syrup which other manufacturers including Madhava say are not used in their product.
Agave nectar is not good for people with candida as some ads maintain. People with candida can take inulin to feed probiotic organisms which compete with candida, but when broken down into a syrup of glucose and fructose, the candida can feed on it.
Saponins produce a potential problem that has not been adequately researched. According to Fallon and Nangel, saponins found in many varieties of agave plants are toxic steroid derivatives, capable of disrupting red blood cells and producing diarrhea and vomiting to be avoided during pregnancy or breastfeeding because they might cause or contribute to miscarriage by stimulating blood flow to the uterus. I don’t think we know that there are enough saponins in a typical serving to be problematical, although it would be a reason to avoid gorging.
What are we left with? Agave nectar is a high fructose syrup which is equivalent to the fructose in high fructose corn syrup (agave is 50-70% fructose, sometimes higher while HFCS is 55% fructose.) It is not as refined as HFCS and in most cases contains some minerals, although probably not enough to prevent mineral depletion. It will interfere with the regulation of appetite, can produce uric acid and will increase the formation of fat and triglycerides. Some manufacturers use GMO enzymes to make agave nectar, some use Aspergillus mold, some use non-GMO enzymes of unknown origin. It is dangerous to diabetics, people with candida and people with obesity tendencies and should only be used in small quantities. The relatively low density of sweetness may make it easier to regulate when poured on food like pancakes.
I think that fruit levulose, complete with associated pectins and other compounds is different from agave nectar in its effect on the body and fruit is better than a refined sweetener. But I also think fructose is actually worse for most people, including diabetics, than glucose. If one is not satisfied with eating fruit for the sweet taste, I suggest using lo han guo sweetener or stevia for teas and for baking, honey or unrefined glucose products like Succanat or molasses.
Since this article was written, the Glycemic Institute halted and banned all research on agave syrup because of the damage it does to diabetics. Report here.
Wikipedia Agave Nectar
Wikipedia Spanish Aguamiel
(Image of commercial agave syrup: House of Sims, via Creative Commons license)
Images of Agave production from Wildpansyflower’s Flicker photostream