ResVida® resveratrol exerts a positive effect on cerebrovascular function, study shows
- Randomized, double-blind, placebo-controlled trial with 36 dementia-free adults with type 2 diabetes
- Supplementation consists of single doses of resVida® (75, 150, and 300mg) at weekly intervals
- Compared to placebo, resVida® significantly improves vasodilator responsiveness in cerebral arteries after a physiologic challenge (hypercapnia) with maximum improvement observed at the lowest dose used (75 mg)
This randomized, double-blind, placebo-controlled trial was designed to determine the most efficacious acute dose of resVida® resveratrol to improve cerebral vasodilator responsiveness (CVR) to hypercapnia in adults with type 2 diabetes.
For this study, researchers enrolled 38 dementia-free, older adults with non-insulin dependent type 2 diabetes. Of these, 36 participants (26 men and 10 women) completed the study; two participants withdrew
prior to the first intervention visit. The participants were typically elderly, obese, mildly hypertensive and insulin resistant. To manage their diabetes, most (n= 28) used oral hypoglycemic agents (namely Metformin and/or sulfonylurea); others (n=8) used diet and exercise alone. The majority (78%) also took medication for hypertension and hypercholesterolaemia. The participants had well-controlled diabetes as measured by HbA1c values, normal cognitive function as measured by the Mini Modified Mental State Examination, but cerebrovascular pathology as measured by cerebral pulsatility indices.
The four intervention visits took place over 28 days at 7-day intervals. Participants attended the clinic in a fasted state at the same time each week. CVR was assessed using an ultrasound probe of the middle cerebral arteries (MCA) and posterior cerebral arteries (PCA), after which participants were given a standard meal to consume within 10 minutes along with their assigned dose of resveratrol to be taken with water. CVR in the MCA was assessed again at 45-60 minutes after resveratrol intake; CVR in the PCA was assessed 90-120 minutes post-intake. This protocol was repeated at weekly intervals with the different resveratrol doses.
Compared to placebo, consumption of each resveratrol dose resulted in significant within-individual improvement of CVR in the MCA (75 mg: 13.8+3.5%, P<.001, 95%CI 6.6-21.1; 150 mg: 8.9+3.5%, P<.016, 95%CI 1.8-16.0; 300 mg: 13.7+3.3%, P<.001, 95%CI 7.0-20.4). Interestingly, the 75-mg dose elicited the largest absolute improvement compare to placebo. In the PCA, the within-individual improvement of CVR was evident following 75 mg resveratrol but not after the higher doses (75 mg: 13.2+4.5%, P<.016; 150 mg: 0.1+6.6%, P<.988; 300 mg: 14.6+9.2%, P<.145).
No adverse events were reported during this intervention.
These preliminary findings provide the first clinical evidence that resVida® resveratrol significantly improves vasodilator responsiveness (CVR) in cerebral arteries in adult with diabetes. Importantly, maximum improvement was observed with the lowest dose used (75 mg), which helps inform a safe and effective dose for further clinical research.