Prepared by Gerald Gawne, Editor, Resveratrol News

America needs truth-in-labeling laws for supplements. That need has been newly emphasized, we believe, by a host of new resveratrol supplement brands arriving on the market recently. The product label claims are often amazing. But where is their science? Where is their Laboratory proof?  

Special Report    Exclusive    
There are many new brands of resveratrol pills being introduced.  One newly introduced brand claims it is the “world’s first red wine anti-aging pill,” but is in fact only the most recent, and violates FDA regulations by claiming it may yield “Super Immunity Against Every Crippling Ailment And Life-Shortening Disease Plaguing Mankind Today!”  Dietary supplements are not supposed to claim they cure or prevent any disease without first obtaining approval from the FDA. 

 A brochure for another recently introduced brand of resveratrol pills, derived from muscadine grapes, overtly alludes to the idea, by virtue of its high antioxidant power, that it can prevent cancer, heart disease, symptoms of menopause, Parkinson’s and a long list of other diseases.  Neophyte dietary supplement manufacturers often step over the line in making unsubstantiated health claims for their products only to find months later the Food & Drug Administration has delivered a letter asking them to substantiate their product claims or withdraw their advertising.  This company also asserts that muscadine grape seed provides greater amounts of resveratrol than other grapes or wine, but there is no listing of the exact amount of resveratrol provided per pill, only that the product is derived from resveratrol-rich muscadine grapes. 

Yet another manufacturer claims its resveratrol formula was developed “after two years of relentless research” to produce a product offering the “most consistent potency and bioavailability of any resveratrol extract.”   Gee - somehow that company’s two-year research project was completed and its product introduced just as resveratrol’s anti-aging properties were first aired in September of 2003 in Nature Magazine.  Additionally, after another competitor included quercetin in its resveratrol pills to improve bioavailability, the aforementioned brand added quercetin (another red wine molecule) even though their initial advertising claimed superior bioavailability without quercetin.

If you think this all sounds confusing, it is.  Manufacturers are cutting corners and producing misleading labels and exaggerated advertising claims in attempts to create the illusion their products are superior in quality or price.  If you can endure reading more, here is a more detailed report.  A comparison chart on various resveratrol dietary supplements in the marketplace today is also provided.   We take no responsibility for the accuracy of claims made by manufacturers.

Source of Resveratrol
Some manufacturers like to make their products appear they contain unique or exotic ingredients.  So they label their resveratrol pills under other names, such as Hu Zhang, Ko-jo-kon, He Shou Wu, Giant Knotweed, Fo-Ti and Polygonum.  Giant Knotweed is just another name of Polygonum, which is the botanical name for this plant.  Virtually all of the Polygonum extracts are from the species Polygonum cuspidatum.   Red wine and red wine grapes are also a source of resveratrol, but extracts from grapes are so expensive compared to Polygonum that most manufacturers combine a miniscule amount of resveratrol from grapes with a predominant amount of Polygonum extract. In other words, the red wine source of resveratrol is just showcased.  Muscadine grape is another grape source of resveratrol, though existing products do not currently identify the percentage of muscadine grape powder that is actually resveratrol.

Trans versus cis resveratrol

All resveratrol raw materials, whether derived from grapes, red wine or the Asian Giant Knotweed (botanical name, Polygonum), are measured for trans resveratrol, believed to be the most active form of resveratrol.  Cis resveratrol is also a minor component in most of these supplements and recent studies show it may have more beneficial properties than first realized.  Cis resveratrol activates various genes in a beneficial manner.  [International Immunopharmacology 5:393-406, 2005]    

A number of manufacturers coyly claim their resveratrol pills only provide trans resveratrol, as if to suggest other inferior brands offer only the less active cis resveratrol. This creates the imagined superiority of one brand over another.  Many consumers call various resveratrol pill makers to inquire if their product contains trans or cis resveratrol.  We think this question is irrelevant and contrived by manufacturers to create doubt in consumers’ minds.

Dosage
Advice on how much resveratrol to take as a dietary supplement is quite sparse.  A website advises chiropractors that “while a recommended daily allowance has yet to be established, researchers believe a minimum of 500 milligrams of resveratrol should be taken to help reduce the risk of cancer.”  [ www.chiroweb.com ]  That would be the equivalent of hundreds of glasses of red wine or a jar full of pills! 

Dosages of resveratrol range from 5 to 50 milligrams per pill in brands surveyed by ResveratrolNews.  There seems to be no consensus on how much is enough or too much.  A 300-milligram per day dose given to animals produced no side effects.  [Toxicolog Science 82:614-9, 2004]  The relatively short half life of resveratrol, about 30 minutes, combined with its rapid metabolism in the liver, probably minimizes any side effects from overdosage.

Most animal studies involve massive doses, ranging from 1600-80,000 milligrams in equivalent human doses, to prove the effect of resveratrol in the laboratory, but are obviously not in the dietary or supplement range.  But a recent study involving prostate cancer says “the relatively low concentration of resveratrol in grapes or wine will likely make it necessary for it to be given as a dietary supplement.”  [Cancer Epidemiology Biomarkers 14: 596-604, 2005]

Manufacturers sometimes fool consumers into thinking their products provide more resveratrol than perceived by the consumer.  How much resveratrol is provided by the following description? (obtained from an actual product label)

We believe consumers are led to believe they are purchasing 32 mg of resveratrol, when a 50% extract would actually provide 16 mg!

Can you decipher how much resveratrol is provided by the label at left?  One hundred milligrams of resveratrol extract provides how much resveratrol?  The label doesn’t say.  Resveratrol extracts are offered as 5%, 15%, 25%, 50%, 90% extracts, etc.  

One hundred milligrams of pure resveratrol would cost far beyond what it costs to rent an apartment for a month.  Do you think it misleads consumers into thinking the product provides 100 milligrams of resveratrol?

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