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Agave: Health Food, Health Fad or Health Fraud? Part One

Posted Oct 01 2010 3:47pm
Agave is still getting a lot of press, and many people think it is a healthy alternative to white sugar.  But is it really?  A fellow RD, Jeff Novick , has written extensively on the topic.  With his permission, I am posting his findings as a "guest" blog, split into two parts.  Below is part one:

Agave has become the sweetener of choice for many health enthusiasts. It is appearing on store shelves everywhere, in many new products and being promoted in magazines and cooking shows.  One of the main benefits we hear is that it is lower in the glycemic index.  Is Agave really a health food and something you should be including in your diet?

No, but to understand why, let us take a closer look at the issues surrounding Agave.

To begin with, to understand Agave, we have to understand some points about fructose which is the main form of sugar in Agave and High Fructose Corn Syrup (HFCS).  Fructose is metabolized differently than other sugars.  Instead of going into the blood stream (where it could raise blood sugar), most of it goes directly to the liver.  This is why Fructose has a lower Glycemic index (GI) as the GI is based on a foods influence on blood sugar.

While many promote this as a positive, as the consumption of fructose tends not to raise blood sugar, fructose, or any concentrated caloric sweeteners high in fructose, can cause elevated levels of triglycerides and increase someone’s risk for heart disease.  It may also somewhat increase the risk of metabolic syndrome/insulin resistance.  And these effects are most likely in those who are insulin resistant, and/or overweight and/or obese.  It also may not affect the satiety mechanism as well as pure sucrose. (1,2)

For the record, these are all many of the reasons we are being told to avoid High Fructose Corn Syrup (HFCS) as it has a higher level of fructose than regular table sugar or regular corn syrup.

Here is the real irony in all of this.

Because of this concern about the elevated levels of fructose in High Fructose Corn Syrup, some health food stores, will not carry any product that has HFCS in it.  Yet on the other hand, they carry a full line of Agave Syrup products on their shelf and carry many products sweetened with Agave syrup.  But realize that Agave syrup has a fructose content of about 70-90%, which is way higher (worse) than HFCS.

On the one hand, consumers, especially the health conscious, are avoiding High Fructose Corn Syrup like the plague because the level of fructose in it is higher (55%) than in regular table sugar/sucrose (50%).  They consider the higher level of fructose a problem.  The fact that is has a lower GI than table sugar is ignored.

On the other hand, Agave syrup has become a popular sweetener because it is said to have a lower GI.  They consider this to be a health benefit.  The fact that it has the highest level of fructose than any other sweetener is ignored.

So, are higher levels of fructose in a concentrated caloric sweetener good or bad?

From my perspective, the Glycemic index (and the glycemic load) are very poor indicators of how healthy a food is and I recommend avoiding choosing foods by it.

However, as Agave is being promoted because of its low Glycemic index, lets look at the Glycemic index issue.

GI (GL) Of Sugars/Sweeteners
Fructose 13 (2)
Sucrose 65 (7)
Glucose 100 (10)
Honey 61 (12) (depending on variety as ratio can be 35-74 for GI and 6-18 for the GL)
Agave Syrup 13 (2) (depending on variety)

High Fructose Corn Syrup would be similar to a honey that has a similar fructose/glucose ratio as the composition and ratio would be the same.  So, let's say a GI of 45 (and a GL of 9) as a honey with the same ratio of fructose/glucose tested at 45 (and 9). HFCS has a lower GI (GL) than table sugar because of the higher level of fructose. So, the higher the percentage of fructose the lower the GI with pure fructose being the lowest.

There are other concerns with HFCS and fructose and so potentially Agave.

A recent study showed that when HFCS was exposed to warm temperatures, it forms hydroxymethylfurfural (HMF),  a potentially dangerous toxic substance, and killed honeybees (3).  Some researchers believe that this chemical, HMF,  may be a factor in Colony Collapse Disorder, a mysterious disease that has killed at least one-third of the honeybee population in the United States.

In the study, the scientists measured levels of HMF in HFCS products from different manufacturers over a period of 35 days at different temperatures.  As temperatures rose, levels of HMF increased steadily.  Levels jumped dramatically at about 120 degrees Fahrenheit.  They also mentioned other studies that have linked HMF to DNA damage in humans.  In addition, HMF breaks down in the body to other substances potentially more harmful than HMF.

The researchers said, "Because HFCS is incorporated as a sweetener in many processed foods, the data from this study are important for human health as well," the report states.

In this study, it was the effect of heat on fructose that formed the toxic chemical, so heating anything high in fructose corn syrup (HFCS) should be a concern.  

However, remember, HFCS is about 55% Fructose and Agave syrup is about 70-90% fructose.  Therefore, heating Agave would potentially create more of this toxic chemical.  Another strike against HFCS, but a bigger strike against Agave.

There is more to the concern about heating fructose.  It turns out that when fructose is heated in can also create Advanced Glycogen End Products (AGEs), which may be harmful as they may play a role in development of atherosclerosis, diabetes, aging and chronic renal failure.

One study compared the amount of AGEs formed between the subject following a traditional omnivorous diet and one following a more traditional vegetarian diet (4).  (NOTE: This was not the same type of vegetarian diet recommended here!)

What the authors found was that the AGEs levels were higher in the vegetarians.  Upon closer examination, they discovered that it was higher levels of fructose in the vegetarian diet that was the main contributor to the increased level of AGEs and stated, "Comparison of nutrition and plasma AGEs in vegetarian and omnivorous groups shows that the higher intake of fructose in alternative nutrition of healthy subjects may cause an increase of AGE levels."

In the above study, most of the AGEs were formed from the fructose which came from honey.  As the authors stated, "Furthermore, the intake of honey is three times higher in vegetarians."

Honey has one of the higher concentrations of fructose out of many of the typical sweeteners available and is around 55% fructose depending on the variety. Agave is 70-90% fructose.  Therefore, substituting Agave for any other sweetener would make the above results (of a potential increase in AGEs) more likely to occur.  This is one more good reason to avoid Agave.

Come back next week to read part two!
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