Consumers of resveratrol pills have certainly been taken for a ride in recent years, starting from anticipation that Harvard scientists had found the holy grail of ageing in the SIrtuin1 gene, to the many other promises that the red wine molecule is reported to offer. Come to find out, not only are research studies about the gene target of resveratrol in question, but the first human study that gained widespread public attention has been halted due to side effects.
The study was divided into two groups, one which was to have received a 5000mg/day dose of resveratrol, the other a combination of resveratrol and the toxic cancer drug botezomib. But were the side effects produced by resveratrol or bortezomib? Were the observed kidney side effects reported in both groups? The researchers have not been forthcoming about this as yet.
The Wall Street Journal (WSJ) chimed in on its health blog page, while posting a Google ad box for resveratrol pills adjacent to their posting. So is this news, or just a fishing lure so WSJ can generate Google click fees?
The WSJ article asks, "Is the bloom off the resveratrol rose?" Really, just three weeks ago researchers at the University of Connecticut showed that resveratrol in relatively low doses averts death from the sudden mortal heart attack, something that aspirin fails to do. About half of the people who succumb to a heart attack were taking aspirin on the day of their demise. Not one major news media outlet published this discovery.
So what did the WSJ blogger recommend? She ushered consumers to Quackwatch for authoritative information. Is the inference here that resveratrol as a dietary supplement is quackery but the drug version isn't, or what? The same molecule is being used in both the drug and dietary supplement.
The dosage employed in the resveratrol drug study was 5,000mg per day. Sirtris, the pharmaceutical company that conducted the study, is hell bent to show you have to use mega-doses to get the job done.
Most of the evidence, however, for the efficacy of resveratrol points to comparatively low doses (100-300mg). These doses are above the dietary range, but achievable with supplements.
There is evidence of resveratrol kidney toxicity in animal studies at very high doses. There is a contrary study showing the human equivalent of 700mg was protective in kidney tissue. Another study showed that the human equivalent of 1,750mg protects the kidneys from toxicity caused by a cancer chemotherapy drug. Another animal study showed no kidney toxicity at a human equivalent dose of 21,000 mg per day in mice.
The question remains: is the smoking gun resveratrol or the cancer drug? Stay tuned.