Side Effects
Some people may experience gastrointestinal issues, headaches, or a feeling of jitteriness. In the mentioned study [1], the majority of adverse events in the higher doses (2.5g and 5.0g) were gastrointestinal symptoms, including nausea, flatulence, abdominal discomfort, and diarrhea. Symptoms typically began 2-4 days into the regimen and improved as the day progressed but would return after the next dose. They resolved within 2 days of completing the 29-day regimen.
- ↑ Brown VA et al.: Repeat dose study of the cancer chemopreventive agent resveratrol in healthy volunteers: safety, pharmacokinetics, and effect on the insulin-like growth factor axis.
Cancer Res
2010. (PMID 20935227)
[PubMed]
[DOI]
[Full text]
Abstract
Resveratrol, a naturally occurring polyphenol, has cancer chemopreventive properties in preclinical models. It has been shown to downregulate the levels of insulin-like growth factor-1 (IGF-I) in rodents. The purpose of the study was to assess its safety, pharmacokinetics, and effects on circulating levels of IGF-I and IGF-binding protein-3 (IGFBP-3) after repeated dosing. Forty healthy volunteers ingested resveratrol at 0.5, 1.0, 2.5, or 5.0 g daily for 29 days. Levels of resveratrol and its metabolites were measured by high performance liquid chromatography-UV in plasma obtained before and up to 24 hours after a dose between days 21 and 28. IGF-I and IGFBP-3 were measured by ELISA in plasma taken predosing and on day 29. Resveratrol was safe, but the 2.5 and 5 g doses caused mild to moderate gastrointestinal symptoms. Resveratrol-3-O-sulfate, resveratrol-4'-O-glucuronide, and resveratrol-3-O-glucuronide were major plasma metabolites. Maximal plasma levels and areas under the concentration versus time curve for the metabolites dramatically exceeded those for resveratrol, in the case of areas under the concentration versus time curve, by up to 20.3-fold. Compared with predosing values, the ingestion of resveratrol caused a decrease in circulating IGF-I and IGFBP-3 (P<0.04 for both), respectively, in all volunteers. The decrease was most marked at the 2.5 g dose level. The results suggest that repeated administration of high doses of resveratrol generates micromolar concentrations of parent and much higher levels of glucuronide and sulfate conjugates in the plasma. The observed decrease in circulating IGF-I and IGFBP-3 might contribute to cancer chemopreventive activity.
