Resveratrol exerts beneficial effects on cerebral blood flow in healthy adults, study shows
- Randomized, double-blind, placebo-controlled, cross-over trial with 22 healthy adults
- Supplementation consists of single doses of 99% pure trans-resveratrol (250 mg or 500 mg)
- Resveratrol increases cerebral blood flow during cognitive performance, compared to placebo
- Improvements in cerebral blood flow variables are dose-dependent
This randomized, double-blind, placebo-controlled, cross-over trial was designed to examine the effect of the oral intake of 99% pure trans-resveratrol on cognitive performance and localized cerebral blood flow (CBF) variables in healthy adults.
For this study, researchers assigned 24 healthy men and women (mean age: 25 years; range 21-29 years) to three treatment groups in random order: placebo, low-dose resveratrol (250 mg) or high-dose resveratrol (500 mg) with 7-day washout periods between treatments. After a 45-minute resting absorption period, the participants performed cognitive tasks that activate the frontal cortex (e.g., serial subtractions and rapid visual information processing tasks) for an additional 36 minutes.
Cerebral blood flow and hemodynamics were assessed by changes in oxygenated and deoxygenated hemoglobin (Hb) levels in the frontal cortex throughout the post-treatment period using near-infrared spectroscopy, a functional brain-imaging technique. Data from two participants who failed to complete the study were not included in the analysis. The presence of resveratrol and its conjugates in plasma was confirmed by HPLC in a separate cohort of 9 healthy men given the same oral doses of resveratrol.
Compared to placebo, both resveratrol treatments significantly (P<.05) increased the level of total-Hb in a dose-dependent manner, indicating better CBF in the prefrontal cortex during performance of cognitive tasks. There was also a significant (P<.05) increase in deoxyhemoglobin after both doses of resveratrol, compared to placebo, suggesting enhanced oxygen extraction throughout task performance. No significant treatment-related differences in cognitive performance or participants’ ratings of mental fatigue were reported. Resveratrol metabolites were present in plasma throughout the cognitive task period.
These preliminary findings indicate that a single dose of trans-resveratrol (250 mg or 500 mg) enhances cerebral blood flow in healthy adults performing cognitive tasks and help inform clinical research related to the brain benefits of resveratrol.