Re: Resveratrol content of wines?

What is your source? Cocoa is rich in several phenols but I have never seen resveratrol mentioned as one of them;-(

What is your source? Cocoa is rich in several phenols but I have never seen resveratrol mentioned as one of them;-(

This abstract compares the antioxidant capacities of several foods including cocoa which tested the highest. They claim that the antioxidant capacity is highly correlated with the phenolic phytochemical content but this still does not proove that cocoa has more resveratrol than red wine.

Conjugation of the drug occurs during first pass metabolism and in this case, resveratrol is conjugated as the glucuronide or sulfate. These conjugates have greater water solubility (for excretion via the kidneys) and are often less active than the parent compound.

"...it seems that the potential health benefits of these compounds based upon the _in vitro_ activities of the unconjugated compounds are unrealistic and have been greatly exaggerated. Indeed, the profusion of papers describing such activities can legitimately be described as irrelevant and misleading. Henceforth, investigations of this nature should focus upon the potential health benefits of their glucuronide and sulfate conjugates."

Clin. Biochem. 36 (2003) 79-87.

Henceforth. Heh.

Darryl.

in

sulfate.

via the

OK, thanks. I think I'll just have to take your word for it.

I haven't taken the time to verify these claims or track down the studies, but I thought this was interesting. One manufacturer of resveratrol has a lengthy rebuttal of the above study, the giste of which is that inclusion of quercetin inhibits liver conjugation, allowing significant amounts of resveratrol to get through 1st-pass liver metabolism unconjugated. Although its plasma half-life is still very short, the company claims that its effects should be measured in terms of gene activation rather than half-life. LEF would seem to agree, since their resveratrol product contains a hefty dose of quercetin. The link to the longevinex article:

"Three previous studies conducted at the Medical School in Pisa, Italy, reveal that while resveratrol undergoes metabolic processes called sulphation and glucuronidation in the liver and duodenum which limits its availability in living tissues, quercetin, a companion antioxidant to resveratrol in red wine, inhibits sulphation and glucuronidation and significantly improves the bioavailability of resveratrol. [Xenobiotica 30: 609-17, 857-66, 1047-54, 2000]"

"All red wine (resveratrol) pills should be provided with quercetin, since many studies confirm there are health benefits derived from moderate red wine consumption but there is not one published study that confirms any health benefits for conventionally made red wine (resveratrol) pills," says Sardi.

Researchers also report injected resveratrol is only measurable in the blood circulation up to 30 minutes after injection and then is rapidly dissipated. "This is true, but the biological activity of resveratrol should not be evaluated by blood levels but on its ability to work at the genetic level, switching on or off certain genes," says Sardi. [Nature. 2003; 425:191-6, 2003]

Considering the length to which I was pursued in proving that their depiction of resveratrol was incorrect (the good old days with Stuart), I take everything mentioned on that website with a grain of bioperine. The incorrect structure was later removed.

I don't have immediate access to Xenobiotica--they sound like interesting articles.

TTYL, Darryl.

Ken, What he was saying is that, when ingested by humans, resveratrol is chemically altered in the liver, either by attachment of a sugar or a sulfate group to one or more of the three phenolic oxygens present in the resveratrol molecule. FWIW, this is basically the purpose of the liver: to metabolize in any of several ways the stuff that we ingest (such as the metabolism of alcohol to fat, f'rinstance).

Mark Lipton

Hi Darryl, how's it feel to have aged 365 days while I've only aged about 240?

:-)

Stuart

Were you traveling near the speed of light for awhile? Or, were you cryogenically frozen for 125 days?