It seems a little pricey, but considering it contains 40mg of trans-resveratrol, its probably not a bad value.

"The supplier of Life Extension's resveratrol provided the following reply:

A competitor claims that all resveratrol products on the market but the one it sells are "unstable" and without "biological activity".  This company claims that resveratrol has to be produced in an oxygen-free environment in order to be stable; otherwise it will break down and become worthless.  The definition of "biological activity" according to this company is the ability to extend the life of yeast cells as exemplified by a commercial kit known as the "Fluor de Lys".  In this assay kit, something is considered "bioactive" if it causes lysine 382 of a p53 gene to fluoresce.  The validity of this test was recently brought into question when it was learned that the results don't hold up in vivo (Kaeberlein, et al.  JBC Papers in Press, 1/31/05). 

The usual definition of "biologically active" is something has an effect on a biological system, such as a cell, an organ or the like.  In that regard, Life Extension's I3C/resveratrol product was recently shown to have biological activity in human colorectal cancer cells where it activated a gene that causes cancer cells to die (Lee, et al.  Biochem Biophys Res Comm 328:63).  LE's resveratrol/I3C combination worked better than either I3C or DIM alone to activate this gene in human colorectal cancer cells.  We will be reporting on this study soon.

Life Extension would never steer you wrong.  Our resveratrol is the of the highest quality available.  It is made from organic French grapes and a plant known as Polygonum cuspidatum.  It is maintained in a natural matrix of complimentary polyphenols and related compounds that help it remain stable and absorbable in the body.  Quercetin, which naturally occurs alongside resveratrol, is added in a synergistic amount for stability and enhanced bioavailability.  As to the question of how long LE resveratrol "stays in the blood", we hope not long since we want to see it in tissues doing something.  In general, resveratrol doesn't stay in circulation very long; it's absorbed through mucous membranes and can be detected in the plasma of animals in as little as five minutes.  We will be able to report to you soon about which genes LE resveratrol affects.  In the meantime, know that LE resveratrol has undergone and passed an accelerated stability study where it maintained potency for up to two years.  It has been tested for potency and meets or exceeds the stated potency.   

Resveratrol in its natural matrix is reported to be very stable.  According to the USDA, peanuts stored for up to 3 years still contained resveratrol (Sanders, et al.  J Agric Food Chem 48:1243), and freeze-dried grape powder also contained resveratrol (Meng, et al.  J Agric Food Chem 52:935).  Last but not least, although light can have a negative effect on resveratrol, you don't have to worry that the resveratrol in your peanut butter will disappear if it's exposed to air: it won't (Ibern-Gomez, et al.  J Agric Food Chem 48:6352).  Despite the claims of a competitor, LE resveratrol is stable, of the highest quality, and biologically active--something you will soon be hearing more about in the near future." - Posted by the Moderator

I eat lots of grapes. I probably get as much reservatol as any of you plus lots of fiber and other goodies.

For the study, which was published in the April 20 issue of Heart Disease Weekly, 40 healthy male rabbits were divided into five equal groups. One group was given water and allowed to continue with their standard diet. The other four groups ate meals that contained nearly 2 percent cholesterol -- considerably high for herbivores, according to the researchers.

One of the high-cholesterol groups was given only water to drink every day. Another group drank water mixed with 3 milligrams of resveratrol for every kilogram the rabbit weighed. The remaining two groups received 4 milliliters of red wine per kilogram of weight per day; one group drank nonalcoholic wine, the other had wine with 12 percent alcohol. (The wines contained close to 4 milligrams of resveratrol per liter.)

Every day, the scientists measured the ability of arteries in the rabbits' ears and legs to dilate, as well as the rabbits' capacity to maintain proper levels of nitric oxide in the bloodstream. Both factors help "relax the vessels and make the blood flow easier," said study spokesman Joseph Wu, a professor of biochemistry and molecular biology at New York Medical College in Valhalla, who has collaborated with the Nanjing Medical University researchers. Having too much nitric oxide in the blood may also cause oxidative damage to the body, according to Wu. The researchers also measured the rabbits' blood pressure and the endothelium cell levels in their blood vessels.

After 12 weeks, the scientists found that the rabbits on a high-cholesterol diet that drank only water showed an approximate 25 percent decrease compared to the control rabbits in their ability to regulate both arterial dilation and nitric oxide levels. On the other hand, rabbits that drank red wine, nonalcoholic wine or the resveratrol-water mix showed similar cardiovascular health as the rabbits on a regular diet.

"The significant [cardiovascular] dysfunctions observed in high-cholesterol diet groups were effectively mitigated by oral administration of resveratrol, red wine and de-alcoholized red wine," the authors wrote.