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

As promised, here is part two of the blog on Agave.  I think this will answer a few more questions for you!

Two last points..

A recent study in the journal Environmental Health (5), found mercury in nearly 50 percent of the tested samples of commercial high fructose corn syrup (HFCS).  A separate study by the Institute for Agriculture and Trade Policy (IATP) detected mercury in nearly one-third of 55 popular brandname food and beverage products where HFCS is the first or second highest labeled ingredient.  As the authors concluded, "With respect to total mercury exposure, it may be necessary to account for this source of mercury in the diet of children and sensitive populations."  This concern would only relate to HFCS and not Agave.

A recent study (6) measured the antioxidant acuity level of several sweeteners and found that refined sugar, corn syrup, and agave nectar contained minimal antioxidant activity, raw cane sugar was slightly higher, and dark and blackstrap molasses had the highest antioxidant activity.  Maple syrup, brown sugar, and honey showed intermediate antioxidant capacity.

So, lets put all of this in perspective...

Are higher levels of fructose in a concentrated caloric sweetener good or bad?

Well, if you think HFCS is bad because of the amount of fructose in it, then Agave must be much worse then HFCS.

If you think Agave syrup is good because it has a very low GI/GL, as a result of the fructose in it, than HFCS must not be that bad and at least better than table sugar because it has a higher level of fructose in it, and so would have a lower GI/GL than table sugar.

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

We just can't argue it both ways.

Now, as we see from these recent studies (1,2), fructose, in excess can create problems as it goes directly to the liver.  However, these problems only existed when excess was consumed as there were no negative effects when less than 50 grams was consumed, even when it was pure fructose.  So again, the real issue is quantity.

If it takes a minimum of 50 grams of fructose to see any negative effect and at least 100 grams of fructose to see a significant negative effect, lets see how these numbers related to potential intakes.

To ingest 50 grams fructose, this would be the equivalent of consuming either 100 grams of sucrose, as sucrose is 50/50 glucose/fructose and about 91 grams of HFCS, as HFCS is 55/45 fructose/glucose.

To ingest 100 grams of fructose, this would be the equivalent of either 200 grams of sucrose, as sucrose is 50/50 glucose/fructose and about 182 grams of HFCS, as HFCS is 55/45 fructose/glucose.

91 grams of HFCS is 370 calories

100 grams of sucrose is 400 calories

182 grams of HFCS is 740 calories

200 grams of Sucrose is 800 calories

I think anyone would agree that 370 to 400 calories, or 740 to 800 calories of either one as part of daily diet would be considered excess. On a 2000 calorie diet, this would be 19% (at 370 calories) to 40% (at 800 calories) of someone's caloric intake.

So, the real issue again, is not which one, but the total amount.  The bottom line, no matter which one you choose to use, quantity is the real issue.

The recommendation I give in my Label Reading talk is to limit their consumption of all concentrated caloric sweeteners to no more than 5% of calories which for someone consuming 2000 calories is 100 calories per day which is 25 grams or about 2 tablespoons. The only exception I give is that if someone has elevated TGs, or at risk for CVD, then they may want to avoid those higher in fructose.

Therefore, limit your consumption of all refined and/or concentrated sweeteners and if heart disease, elevated triglycerides, insulin resistance, diabetes and/or weight are concerns of yours, avoid the ones higher in fructose especially Agave.



1) Br J Nutr. 2008 Nov;100(5):947- 52. Consumption of fructose-sweetened beverages for 10 weeks increases postprandial triacylglycerol and apolipoprotein- B concentrations in overweight and obese women.

Fructose consumption in the USA has increased over the past three decades.  During this time, obesity, insulin resistance and the metabolic syndrome have also increased in prevalence.  While diets high in fructose have been shown to promote insulin resistance and increase TAG concentrations in animals, there are insufficient data available regarding the long-term metabolic effects of fructose consumption in humans.  The objective of the present study was to investigate the metabolic effects of 10-week consumption of fructose-sweetened beverages in human subjects under energy-balanced conditions in a controlled research setting.  Following a 4-week weight-maintaining complex carbohydrate diet, seven overweight or obese (BMI 26.8-33.3 kg/m2) postmenopausal women were fed an isoenergetic intervention diet, which included a fructose-sweetened beverage with each meal, for 10 weeks.  The intervention diet provided 15% of energy from protein, 30% from fat and 55% from carbohydrate (30% complex carbohydrate, 25% fructose).  Fasting and postprandial glucose, insulin, TAG and apoB concentrations were measured.  Fructose consumption increased fasting glucose concentrations and decreased meal-associated glucose and insulin responses (P = 0.0002, P = 0.007 and P = 0.013, respectively).  Moreover, after 10 weeks of fructose consumption, 14 h postprandial TAG profiles were significantly increased, with the area under the curve at 10 weeks being 141% higher than at baseline (P = 0.04).  Fructose also increased fasting apoB concentrations by 19% (P = 0.043 v. baseline).  In summary, consumption of fructose-sweetened beverages increased postprandial TAG and fasting apoB concentrations, and the present results suggest that long-term consumption of diets high in fructose could lead to an increased risk of CVD. PMID: 18384705


2) Am J Clin Nutr. 2008 Nov;88(5):1419- 37.  Fructose consumption and consequences for glycation, plasma triacylglycerol, and body weight: meta-analyses and meta-regression models of intervention studies.

BACKGROUND: The glycemic response to dietary fructose is low, which may improve concentrations of glycated hemoglobin (HbA(1c), a marker of dysglycemia).  Meanwhile, adverse effects on plasma triacylglycerol (a marker of dyslipidemia) and body weight have been questioned. Such effects are reported inconsistently.  OBJECTIVE: We aimed to evaluate the effect of fructose on these health markers, particularly examining treatment dose and duration, and level of glycemic control.  DESIGN: A literature search was conducted for relevant randomized and controlled intervention studies of crystalline or pure fructose (excluding high-fructose corn syrup), data extraction, meta-analyses, and modeling using meta-regression.  RESULTS: Fructose intake < 90 g/d significantly improved HbA(1c) concentrations dependent on the dose, the duration of study, and the continuous severity of dysglycemia throughout the range of dysglycemia.  There was no significant change in body weight at intakes <100 g fructose/d.  Fructose intakes of <50 g/d had no postprandially significant effect on triacylglycerol and those of or=100 g fructose/d, the effect on fasting triacylglycerol depended on whether sucrose or starch was being exchanged with fructose, and the effect was dose-dependent but was less with increasing duration of treatment.  Different health types and sources of bias were examined; they showed no significant departure from a general trend.  CONCLUSIONS: The meta-analysis shows that fructose intakes from 0 to >or=90 g/d have a beneficial effect on HbA(1c).  Significant effects on postprandial triacylglycerols are not evident unless >50 g fructose/d is consumed, and no significant effects are seen for fasting triacylglycerol or body weight with intakes of

3) J Agric Food Chem. 2009 Jul 31. [Epub ahead of print] Formation of Hydroxymethylfurfural in Domestic High-Fructose Corn Syrup and Its Toxicity to the Honey Bee ( Apis mellifera ).

In the United States, high-fructose corn syrup (HFCS) has become a sucrose replacement for honey bees and has widespread use as a sweetener in many processed foods and beverages for human consumption.  It is utilized by commercial beekeepers as a food for honey bees for several reasons: to promote brood production, after bees have been moved for commercial pollination, and when field-gathered nectar sources are scarce.  Hydroxymethylfurfural (HMF) is a heat-formed contaminant and is the most noted toxin to honey bees.  Currently, there are no rapid field tests that would alert beekeepers of dangerous levels of HMF in HFCS or honey.  In this study, the initial levels and the rates of formation of HMF at four temperatures were evaluated in U.S.-available HFCS samples.  Different HFCS brands were analyzed and compared for acidity and metal ions by inductively coupled plasma mass spectroscopy.  Levels of HMF in eight HFCS products were evaluated over 35 days, and the data were fit to polynomial and exponential equations, with excellent correlations. The data can be used by beekeepers to predict HMF formation on storage. Caged bee studies were conducted to evaluate the HMF dose-response effect on bee mortality.  Finally, commercial bases such as lime, potash, and caustic soda were added to neutralize hydronium ion in HMF samples, and the rates of HMF formation were compared at 45 degrees C. PMID: 19645504

4) Advanced Glycation End Products and Nutrition  Physiol. Res. 51: 313-316, 2002

Advanced glycation end products (AGEs) may play an important adverse role in process of atherosclerosis, diabetes, aging and chronic renal failure.  Levels of N(epsilon)-carboxymethyllysine and fluorescent AGE values were estimated in two nutritional population groups--alternative group (vegetarians--plant food, milk products, eggs) and traditional group (omnivorous subjects).  Vegetarians have a significantly higher carboxymethyllysine content in plasma and fluorescent AGE values.  Intake of proteins, lysine and monosaccharides as well as culinary treatment, consumption of food AGEs (mainly from technologically processed products) and the routes of Maillard reaction in organism are the substantial sources of plasma AGEs.  Vegetarians consume less proteins and saccharides.  Lysine intake is significantly reduced (low content in plant proteins). Subjects on alternative nutrition do not use high temperature for culinary treatment and consume low amount of technologically processed food.  Fructation induced AGE fluorescence is greater as compared with that induced by glucose.  It is due to higher participation of a more reactive acyclic form of fructose.  Intake of vegetables and fruit with predominance of fructose is significantly higher in vegetarians.  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. PMID: 12234125

5) Environ Health.  2009 Jan 26;8:2.  Mercury from chlor-alkali plants: measured concentrations in food product sugar.

Mercury cell chlor-alkali products are used to produce thousands of other products including food ingredients such as citric acid, sodium benzoate, and high fructose corn syrup.  High fructose corn syrup is used in food products to enhance shelf life.  A pilot study was conducted to determine if high fructose corn syrup contains mercury, a toxic metal historically used as an anti-microbial.  High fructose corn syrup samples were collected from three different manufacturers and analyzed for total mercury.  The samples were found to contain levels of mercury ranging from below a detection limit of 0.005 to 0.570 micrograms mercury per gram of high fructose corn syrup.  Average daily consumption of high fructose corn syrup is about 50 grams per person in the United States.  With respect to total mercury exposure, it may be necessary to account for this source of mercury in the diet of children and sensitive populations. PMID: 19171026

6) Total Antioxidant Content of Alternatives to Refined Sugar, JADA. Volume 109, Issue 1, Pages 64-71 (January 2009

Abstract

Background: Oxidative damage is implicated in the etiology of cancer, cardiovascular disease, and other degenerative disorders.  Recent nutritional research has focused on the antioxidant potential of foods, while current dietary recommendations are to increase the intake of antioxidant-rich foods rather than supplement specific nutrients.  Many alternatives to refined sugar are available, including raw cane sugar, plant saps/syrups (eg, maple syrup, agave nectar), molasses, honey, and fruit sugars (eg, date sugar).  Unrefined sweeteners were hypothesized to contain higher levels of antioxidants, similar to the contrast between whole and refined grain products.

Objective: To compare the total antioxidant content of natural sweeteners as alternatives to refined sugar.

Design: The ferric-reducing ability of plasma (FRAP) assay was used to estimate total antioxidant capacity.  Major brands of 12 types of sweeteners as well as refined white sugar and corn syrup were sampled from retail outlets in the United States.

Results: Substantial differences in total antioxidant content of different sweeteners were found.  Refined sugar, corn syrup, and agave nectar contained minimal antioxidant activity (<0.01 mmol FRAP/100 g); raw cane sugar had a higher FRAP (0.1 mmol/100 g). Dark and blackstrap molasses had the highest FRAP (4.6 to 4.9 mmol/100 g), while maple syrup, brown sugar, and honey showed intermediate antioxidant capacity (0.2 to 0.7 mmol FRAP/100 g).  Based on an average intake of 130 g/day refined sugars and the antioxidant activity measured in typical diets, substituting alternative sweeteners could increase antioxidant intake an average of 2.6 mmol/day, similar to the amount found in a serving of berries or nuts.

Conclusion: Many readily available alternatives to refined sugar offer the potential benefit of antioxidant activity.