But what are glyconutrients and, more important, is there any truth to these impressive claims? WDDTY separates the facts from the fiction.
What are glyconutrients?
Recently, there's been a lot of interest in glycobiology, the study of the structure, biosynthesis and biology of saccharides-sugar chains or glycans-which are widely distributed in nature. From this, an entire industry has emerged, based on the sale of plant extracts called 'glyconutrients', a newly invented term that refers to sugars ('glyco') that the body can use ('nutrients'). The glyconutrient in- dustry now has a worldwide sales force of over half a billion people, and sells nearly half a billion dollars' worth of products each year (Glycobiology, 2008; 18: 652-7).
Perhaps the best known of these single sugars is glucosamine, which has growing evidence to support its use in the treatment of arthritis (Arthroscopy, 2009, 25: 86-94).
Nevertheless, the term 'glyco-nutrients' is now being applied to new supplements that offer a mix of the various sugars found in plants.
Of the many companies that are currently selling glyconutrients, Mannatech, an international company based in Texas, is the most successful. Its flagship product, sold as both a stand-alone and as a component in other products, is Ambrotose Com-plex, a patented blend of plant-sourced polysaccharides, including aloe vera extract (inner-leaf gel), ara-binogalactan (gum from the wood of Larix spp), ghatti gum (from guar beans) and tragacanth gum (from Astragalus legumes). The company claims that Ambrotose Complex was the "world's first natural plant polysaccharide/glyconutritional product" and, so far, more than 4.5 million units have been sold worldwide.
Although Mannatech is careful to point out that its products are not intended to diagnose, treat, cure or prevent any disease, the company does claim that Ambrotose can help to:
o support cell-to-cell communication
o improve immune-system health
o support digestive function and promote gastrointestinal health
o enhance cognitive brain function, including memory, and
o improve mood and decrease irritability.
Mannatech also states that "no other combination of vitamins, minerals, amino acids or herbals can provide the benefits found in our Ambrotose Complex".
Where's the evidence?
There have been a number of published scientific studies on Mannatech's glyconutrient formula, including double-blind, placebo-controlled clinical trials. In one of the latest studies, researchers in Australia investigated the effects of saccharide supplementation (Ambrotose Com-plex powder) on cognition and well-being in 109 middle-aged adults. Each participant took a teaspoonful of Ambrotose (3.6 g/day) or a placebo twice a day for 12 weeks. Before and after this period of supplementation, they all had filled in a number of questionnaires assessing their mental functioning and feelings of well-being. The results showed significant improvements in both memory and wellbeing in the Ambrotose group (Dev Neuropsychol, 2010; 35: 66-80).
In another study, researchers at Howard University in Washington, DC, looked at the impact of Ambrotose Complex on the brain function of 62 healthy college students. The study showed that a single, 1-tbsp serving of Ambrotose significantly improved their visual discrimination and simple working-memory skills (Percept Mot Skills, 2009; 108: 259-70).
Other trials show that Ambrotose has antioxidant activity as well as prebiotic effects. One test-tube study revealed that both Ambrotose Complex and Advanced Ambrotose powder exhibited bifidogenic and lactobacillogenic effects-in other words, they encouraged the growth and proliferation of both these probiotic organisms (Int J Food Microbiol, 2010; 139: 168-76)-while a preliminary trial involving 21 healthy volunteers demonstrated that four capsules/day of the Ambrotose AO supplement increased blood 'oxygen radical absorption capacity' (ORAC, a way to measure antioxidant protection) by 36.6 per cent (BMC Complement Altern Med, 2010; 10: 16).
Further studies suggest that Mannatech's glyconutrients may even be useful for specific medical conditions. Indeed, a review article of glyconutrients and the study of glycobiology by scientists in Galves-ton, TX, describes how these nutrients have been tested in patients with asthma, cystic fibrosis, myasthenia gravis (an autoimmune neuro-muscular disease) and other chronic illnesses-with promising results (Explore [NY], 2006; 2: 488-94).
One six-week study carried out by Mannatech itself tested a "glyco-nutritional product containing sac-charides" in 17 children with ADHD. The researchers reported that the supplement reduced the severity of ADHD and its associated symptoms within the first two weeks of the study (Integr Physiol Behav Sci, 1998; 33: 49-60).
Another study on human cells suggested that glyconutrients may be useful for those suffering from chronic fatigue syndrome (CFS). The researchers, at the University of California at Irvine, added a glyconutrient formula to the blood cells of patients with CFS and found that the "glyconutrients improved abnormal immune parameters" (Integr Physiol Behav Sci, 1998; 33: 280-7).
More recently, a rat study showed that both Ambrotose Complex and Advanced Ambrotose had beneficial effects on chemically induced colitis, although these results may not necessarily apply to humans (Dig Dis Sci, 2010; 55: 1278-85).
Although all of this evidence may at first appear to constitue an impressive body of research, a closer look reveals that all of these studies were supported by Mannatech in some way (which Mannatech admits on its website).
Even the review article published in Explore (Explore [NY], 2006; 2: 488-94) is supported by Mannatech and written by researchers who have acted as Mannatech consultants. Moreover, the article cites positive studies that were published in the Proceedings of the Fisher Institute for Medical Research. News reports in 2006 revealed that the directors of the Fisher Institute for Medical Research were also major Mannatech shareholders (Glycobiology, 2008; 18: 652-7).
However, in all fairness, it should be pointed out that all these practices are standard in the drug industry. There appear to be no studies on PubMed to support the use of Mannatech's flagship product, but this may also reflect the fact that supplement companies have no choice but to pay for their own research.
Clearly, there's a distinct lack of independent research into glyco-nutrients. Although this doesn't necessarily mean that we should discount all of the company-funded research, it's nevertheless been well documented that company-funded studies are more likely to report positive findings than are independent ones.
Many orthodox scientists take issue with the supposed medicinal effect of glyconutrients as supplements. Drs Ronald Schnaar and Hudson Freeze, at the Johns Hopkins School of Medi-cine in Baltimore, MD looked at Ambrotose's individual components, and remain unconvinced of their efficacy as supplements. For example, although aloe vera gel has long been reported to have medicinal value for burns and other skin lesions, taking aloe gel glucomannan (as found in Ambrotose) orally is not well studied. However, one clinical study has found that oral aloe glucomannan failed to either enhance immune-system func-tion or decrease viral load in AIDS patients (J Acquir Immune Defic Syndr Hum Retrovirol, 1996; 12: 153-7).
As the components of Ambrotose Complex-all of which are dietary fibres-are largely indigestible, say Schnaar and Freeze, they therefore question whether these ingredients could really deliver biologically meaningful concentrations of indi-vidual monosaccharides to human tissues.
"While there are clearly established health benefits of including indiges-tible fibre in the diet, the implication that larch-bark arabinogalactans, aloe vera gel glucomannan and plant-gum emulsifiers are a biologically signifi-cant source of dietary monosac-charides required for optimal cellular health appears to the authors to be unsupported," the article states.
Besides a relatively high price tag, perhaps the biggest cause for concern is the organization of Mannatech, as a decentralized multilevel marketing company. Any MLM operates with an army of self-employed entrepreneurs, all selling the product through independent networks and free to make any claims.
Indeed, in 2007, Mannatech and its 'associates' (sales force) were accused by the Attorney General of Texas of using ". . . false, misleading, or deceptive acts or practices . . ." to "sell [glyconutrients] as a way to cure, mitigate, treat, or prevent diseases, illnesses or serious conditions, despite [their] admission that the products do not cure any disease" (Glycobiology, 2008; 18: 652-7).
In the US, supplement companies are free to sell their products, but can run foul of the law if they make any therapeutic claims.
Mannatech reportedly reached a settlement for this case, and for a class-action lawsuit brought against it in 2005, in 2009.
The bottom line
Ultimately, there's a lack of inde-pendent research on glyconutrients, and certainly no proof that these supplements can prevent or cure any particular disease. Furthermore, other, far cheaper nutrients have been proven to provide the same kinds of benefits claimed thus far. Extracts of the herb Ginkgo biloba, for instance, have been shown to improve memory and other mental abilities (J Altern Complement Med, 2000; 6: 219-29).
Many glycobiologists view the term 'glyconutrient' as nothing more than a marketing gimmick used to sell products rather than an accepted medical/scientific term.
There is a legitimate field of research called 'glycobiology', which is now finding that glycans are key components in human physiology.
As alternative cancer specialist Dr Ralph Moss recently wrote: 'Glyco-biology is a promising avenue of research, to be sure. However, network marketing creates a rah-rah atmosphere, in which a chemical becomes a product and a product then becomes a profit center . . . and an ideological cause." That cause-that glyconutrients are an all-purpose cure-all-remains pure hype.
WDDTY VOL. 21 ISSUE 7