1. A phase 1 pilot trial was conducted to evaluate the safety and tolerability of escalating doses (500-4000 mg/day) of pulverized muscadine grape skin in 14 men (median age 61) with biochemically recurrent prostate cancer. Effect of muscadine on PSA doubling time was measured as a secondary outcome. After a median follow-up period of 19.2 months, muscadine was found to be safe and tolerable (no serious adverse events) up to the maximum dose tested. A median, non-significant increase in PSA doubling time of 5.3 months was also observed.1
2. In a phase 2, randomized, double-blind, placebo-controlled, multicenter, clinical trial designed as a follow up to the previous study, two doses (500 mg/day and 4,000 mg/day) of pulverized muscadine grape skin were administered to 125 men (median age 68) with biochemically recurrent prostate cancer for a maximum duration of 12 months. At the end of the study period, median increases in PSA doubling time of 0.9-1.5 months were observed in the muscadine group, but these findings did not differ significantly from changes observed in the placebo group. In a subgroup of men with heightened risk of prostate cancer aggressivity due to an SOD2 Ala/Ala polymorphism, PSA doubling time increased by 10.3 months, suggesting muscadine may be of particular benefit to men with this genotype.2
3. A randomized, controlled clinical trial was performed to evaluate the metabolic effects of consuming muscadine grape juice, muscadine wine, and dealcoholized muscadine wine. A group of 29 subjects (mean age 58.7) with type 2 diabetes were asked to drink 150 ml/day of one of muscadine beverages for 28 days. A control group of non-diabetic subjects was given no treatment. At the end of the test period, elevated blood insulin levels decreased significantly (-35.8%) in diabetic subjects consuming the dealcoholized muscadine wine. Non-significant reductions in fasting blood glucose were also noted in all muscadine groups compared to a slight increase in the control group. In addition, diabetic subjects consuming muscadine wine experienced significant improvements in liver function tests (LD, AST, ALT).3
4. A randomized, double-blind, placebo-controlled, crossover trial evaluated the effects of 1300 mg/day of muscadine grape seed powder in a group of 50 men and women (18-65 years old) with either pre-existing cardiovascular disease (CVD) or an elevated risk of developing CVD. After four weeks, researchers observed a significant increase in resting brachial artery diameter in subjects taking muscadine grape seed compared to those taking placebo. Other CVD parameters including blood pressure, flow-mediated artery dilation, and lipid peroxidation were not significantly changed by muscadine supplementation.4
2. In a phase 2, randomized, double-blind, placebo-controlled, multicenter, clinical trial designed as a follow up to the previous study, two doses (500 mg/day and 4,000 mg/day) of pulverized muscadine grape skin were administered to 125 men (median age 68) with biochemically recurrent prostate cancer for a maximum duration of 12 months. At the end of the study period, median increases in PSA doubling time of 0.9-1.5 months were observed in the muscadine group, but these findings did not differ significantly from changes observed in the placebo group. In a subgroup of men with heightened risk of prostate cancer aggressivity due to an SOD2 Ala/Ala polymorphism, PSA doubling time increased by 10.3 months, suggesting muscadine may be of particular benefit to men with this genotype.2
3. A randomized, controlled clinical trial was performed to evaluate the metabolic effects of consuming muscadine grape juice, muscadine wine, and dealcoholized muscadine wine. A group of 29 subjects (mean age 58.7) with type 2 diabetes were asked to drink 150 ml/day of one of muscadine beverages for 28 days. A control group of non-diabetic subjects was given no treatment. At the end of the test period, elevated blood insulin levels decreased significantly (-35.8%) in diabetic subjects consuming the dealcoholized muscadine wine. Non-significant reductions in fasting blood glucose were also noted in all muscadine groups compared to a slight increase in the control group. In addition, diabetic subjects consuming muscadine wine experienced significant improvements in liver function tests (LD, AST, ALT).3
4. A randomized, double-blind, placebo-controlled, crossover trial evaluated the effects of 1300 mg/day of muscadine grape seed powder in a group of 50 men and women (18-65 years old) with either pre-existing cardiovascular disease (CVD) or an elevated risk of developing CVD. After four weeks, researchers observed a significant increase in resting brachial artery diameter in subjects taking muscadine grape seed compared to those taking placebo. Other CVD parameters including blood pressure, flow-mediated artery dilation, and lipid peroxidation were not significantly changed by muscadine supplementation.4