Unlike most dietary supplements, hundreds of well managed scientific studies and trials have upheld resveratrol’s potentially critical health properties as a treatment for diabetes, cancer, inflammatory and auto-immune diseases and neurological conditions. Without passing judgement on resveratrol’s actual efficacy or effectiveness it is clear that many people purchase resveratrol as a preventative or treatment for a serious medical condition. If the resveratrol these consumers purchase is not a high quality, properly manufactured, bio active compound they are not only wasting their money but are also failing to obtain whatever benefits resveratrol may offer for the amelioration of their condition.
The criteria below are based upon valid scientific principals and accepted standards for the evaluation of either a of a functional dietary supplement such as resveratrol. The standards can also be used in judging other supplements.
Many resveratrol suppliers do not disclose the exact form of resveratrol or the quantity which is contained in their supplement. Some simply call their main ingredient “red wine complex” or a “proprietary blend”. Given that red wine contains less than 1% resveratrol it seems a bit strange that a company would use this description to label a resveratrol product unless the purpose was to conceal the actual ingredients in the product. A proprietary blend can be anything, but is unlikely to consist of pure resveratrol given the relatively high cost of quality resveratol versus other possible ingredients.
Resveratrol is composed of two principal isomers, trans-resveratrol and cis-resveratrol. Only the trans-isomer has been associated with health benefits. The cis isomer actually acts to nullify the effects of trans-resveratrol. Unless the seller states on the label that the product consists entirely of the trans-resveratrol form it is highly likely that it contains either some or all of cis-resveratrol, which is, by an order of magnitude, the less costly form of resveratrol.
A size 0 capsule is able to contain about 500mg of resveratrol, if the base material is processed using pharmaceutical technology and equipment. This is the largest size capsule that is quite easily swallowed by most people. Sellers who use larger capsules do so to compensate for the fact that they are simply stuffing raw extract into a capsule without going through the time and expense of purifying and granulating the resveratrol extract. A larger capsule size also allows for the use of various fillers and chemicals such as silicon, magnesium sterate, cellulose, and other additives. The best quality resveratrol supplements are contained in a size 0 capsule and contain no additives or fillers at all. There is no reason why you should have to consume sand and other inert ingredients in your supplement simply because your supplier can not be bothered with using more sophisticated processing and filling technology.
Is red wine the best source of resveratrol?
Although much of the news about resveratrol mentions the red wine grape as the source, wine grapes are not a practical source of resveratrol for two important reasons. First grapes are subjected to a wide range of toxic chemicals in the cultivation process. Fungicides, pesticides, chemical fertilizers and many more chemicals are sprayed directly on wine grapes. Since resveratrol comes from the skins it is very difficult to eliminate contamination in the resveratrol concentrate. The second reason wine grapes are not a good source of resveratrol is that it is impossible to produce a high potency supplement using grape extract. The concentration of resveratrol in grape skins is simply too low. This is why in all of the animal and tissue studies on the health benefits of resveratrol the source of the resveratrol was the Giant Knotweed plant, which grows without fertilizers or agricultural chemicals in the wild.
Capsules and packaging
The capsules themselves should be all vegetable such as Pfizer Vcaps rather than clear gelatin, which is made from an animal product. Not only is an all vegetable capsule healthier to consume than an animal by product but it is designed to better regulate the release of the active ingredients into your digestive tract when taken orally. What is the use of taking a natural supplement if the capsule is derived from the collagen inside animals’ skin and bones?
Resveratrol is highly susceptable to deterioration by oxidation and exposure to ultraviolet light. A quality supplement will be protected from oxidation during manufacture through the use of nitrogen gas filled processing lines. The bottle in which the supplement is contained should also use an inert gas to prevent oxidation during shipment. However once the bottle is opened oxygen is allowed to enter. If active packaging technology is not employed to protect against this damage the shelf life of the product will be seriously degraded. An oxygen absorber system is needed to capture the oxygen which enters the bottle when a capsule is retrieved.
The appropriate dosage of trans-resveratrol is a highly contentious issue, with respect to the rhetoric of resveratrol suppliers that is. The science regarding dosage is relatively clear however. Although doses of around 100mg appear from some studies to have potentially important preventative effects, the consensus is that at least 250mg is required to reach the threshold for efficacy as demonstrated in most animal and in vitro studies undertaken to date. This equates to the human equivalent of the dosage used in the Dr. Sinclair study and many other studies. The dose recommended by most clinicians for treatment of an existing condition ranges from 1,000mg to 4,000mg. however it is recommended that one consult a physician before taking a dose over 1,000mg daily. No toxicity or serious adverse effects were observed in several animal and human studies in which up to 5,000mg was given on a daily basis for an extended period of time. In animal studies dosages up to the human equivalent of 30,000mg have been tolerated with only minor adverse effects.
Natural versus synthetic resveratrol
Synthetic resveratrol can be produced using one of two methods, fermentation and chemical engineering. In the case of fermentation a yeast or bacteria is genetically modified to produce resveratrol. Chemically engineered resveratrol is constructed from a broth of compounds using organic chemistry to engineer the molecule. Both processes are fraught with potential pitfalls. In the case of fermentation often what occurs is that bits of the bacteria or yeast DNA used to produce the resveratrol show up in the finished material. This means that if you use this product you are consuming a novel substance, that is a compound that has never been previously consumed by a human, with potentially toxic or other other unknown effects. In the case of a chemically engineered resveratrol product the issue is contamination by small amounts of the chemicals used to produce the synthetic resveratrol. On a typical HPLC graph of a chemically engineered resveratrol there will almost always be spikes on the chart of what are what are referred to as “unknowns”. These trace chemicals are by products of the creation of the primary compound which are unidentified and assumed or hoped to be non toxic. Furthermore, naturally extracted resveratrol from the polygonum cuspidatum plant is known to be non toxic and effective. Neither properties have been verified for certain in regard to synthetic resveratrol. There is only one reason some suppliers use synthetic resveratrol in place of natural resveratrol from polygonum cuspidatum. The reason is the far lower cost of synthetic resveratrol. If a supplier does not disclose which type of resveratrol is contained in its products you can assume that it is the synthetic variety.
Quercetin or no quercetin?
Quercetin is a potent antioxidant in its own right, however it should not be combined with resveratrol or even taken within at least 8 hours of taking a resveratrol supplement. The reason, which was only recently discovered, is that quercetin blocks the metabolites of resveratrol from entering your blood stream. Quercetin also down regulates sirtuins, precisely the opposite effect of resveratol. Until a few years ago it was assumed that adding quercetin was a good thing since the importance of the metabolites was not understood. At that time it was assumed that the metabolites were not responsible for the metabolic and epigenetic effects of resveratrol. Based upon several highly regarded studies we now know that it is very likely that the beneficial effects of resveratrol actually derive principally from these metabolites rather then from the free resveratrol. These metabolites are bioactive products of the breakdown of resveratrol by the liver and endothelial cells lining the small intestine. By blocking these sulphates and glucordinates quercetin interferes with the ability of resveratrol to activate the sirtuins, specifically SirT2, the so called anti aging gene, and blocks other signalling pathways through which resveratrol operates, and which are responsible for many of the desirable health effects of resveratrol. Moreover, the half life of the metabolites is several hours whereas the half life of free resveratrol is only about 12 minutes. In a 2009 study of resveratrol’s effects on inducing the creation of hemoglobin cells in Thalasemmia patients’ blood it was found that quercetin totally blocked the ability of resveratrol to create the new red blood cells. Quercetin also nullified the anti inflammatory property of resveratol in an informal trial of resveratol’s pallative effect on arthritis. There is no scientific justification for adding quercetin to a resveratol supplement. If one wishes to take quercetin it is readily available as a low cost supplement that may be taken by itself.
The credentials of your supplier
The media coverage of the studies demonstrating the potential benefits of resveratrol has attracted a flood of new and clearly disreputable resveratrol sellers to the market. These companies have no experience in producing a food or health supplement, no scientific staffs, labs or other technical resources, no established quality control standards and no history by which one can judge their reliability and integrity. Many of these companies use a form of the word resveratrol in their names and sell only via a web site. The lawyers for Dr. Mehmet Oz and Oprah Winfrey recently filed federal law suits against over 50 of these companies for illegally using their trademarks and making false claims that their products were endorsed by these well know personalities.
Your resveratol supplier should be a manufacturer rather than simply a reseller of resveratrol from unknown sources, it should have a history of at least ten years, preferably more, of ethical business operations. It should offer a range of products not just one or two virtually identical products. Its products should have passed Consumer Lab’s recently updated evaluation of resveratrol brands, and its web site should provide easy methods to contact the company if you have any questions, complaints or a request for a refund. If the company offers a monthly recurring order program a clear and convenient means of canceling your subscription should be offered. If the company’s products are not available in brick and mortar stores such as GNC, The Vitamin Shop and other reputable resellers it should probably be avoided. Anyone can sell a product over the Internet but to have one’s products accepted by major Health and Supplement stores requires liability insurance, thorough testing of the products’ quality and vetting of the company and its principals.
The gold standard for a manufacturer is for its products to win widespread acceptance by the medical and research communities. Resveratrol used in human trials at institutions such as the Albert Einstein Medical School and the NIH are the purest and most thoroughly tested supplements available to the general public.