Resveratrol in the management of human cancer: how strong is the clinical evidence?

Among the plethora of biochemical mechanisms engaged by resveratrol in preclinical systems, its anticarcinogenic effects represent some of the most convincing and intriguing. As outlined in this review, there is considerable interest in developing resveratrol for cancer prevention and treatment. The plasma pharmacokinetics of resveratrol in humans are now reasonably well defined, and studies have shown that repeated daily doses up to 1 g are safe and well tolerated, although gastrointestinal toxicity is observed at higher intakes. However, care is needed regarding underlying conditions in specific patient groups, and there is potential for drug interactions at doses greater than 1 gram. Little is known regarding the pharmacodynamic effects of resveratrol in humans, but the observation that it modulates components of the insulin-like growth factor system in the plasma of volunteers is encouraging. While the knowledge base that helps determine whether resveratrol may be useful in cancer management has increased substantially in recent years, important questions remain.