Rationale: Survivors of childhood cancer are at an increased risk of developing cardiovascular risk factors as well as early cardiovascular disease, likely due to the intensive therapeutic regimen used to treat their cancer. Purple grape juice (PGJ) is a rich source of flavonoids and a powerful antioxidant. Clinical studies in both diseased and healthy adults suggest that daily consumption of PGJ contributes to increased antioxidant capacity, reduced low-density lipoprotein (LDL) oxidation, and improved vasodilation. Purpose: This randomized clinical trial is evaluating whether purple grape juice can reduce oxidative stress and improve the vascular health of survivors of childhood cancer in the early stages of cardiovascular disease.
Primary Objective: * To evaluate the effect of PGJ on endothelial function, a key measure of vascular health and considered a barometer for cardiovascular disease risk. Secondary Objective: * To evaluate the effect of PGJ on biomarkers of vascular and systemic oxidative stress. Outline: Patients undergo a 4-week washout period and refrain from consuming any type of juice, juice drink (less than 100% juice), wine or grapes. Patients are then randomized to 1 of 2 arms. Arm 1: Beginning in week 4, patients consume 6 ounces of purple grape juice (PGJ) twice daily for 4 weeks. Beginning in week 12, after a 4 week washout period, patients crossover to consume apple juice (AJ) as in Arm 2. Arm 2: Beginning in week 4, patients consume 6 ounces of AJ twice daily for 4 weeks. Beginning in week 12, after a 4 week washout period, patients crossover to consume PGJ as in Arm 1.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
NONE
Enrollment
24
6 ounces of purple grape juice consumed twice daily either during first or second 4 week supplementation period, depending on sequence randomization
6 ounces of clear apple juice consumed twice daily either during first or second 4 week supplementation period, depending on sequence randomization
Minnesota General Clinical Research Center
Minneapolis, Minnesota, United States
Change in Endothelial Function (Reactive Hyperemia Peripheral Arterial Tonometry (RH-PAT) Index Score)
Difference of least square means (95% Confidence Interval) in RH-PAT Index Scores between juice groups. Higher RH-PAT scores indicate better endothelial function; a positive difference of least square means is suggestive of an improvement in endothelial function. Probes were placed on the index fingers of both hands and a blood pressure cuff was placed on one arm. The cuff was inflated to suprasystolic pressure and the digital pulse volume was recorded before, during \& after a 5 minute occlusion period. The ratio of the hyperemic and the baseline pulse amplitude (corrected for the same ratio on the control finger) was calculated and expressed as the RH-PAT index score. Lower scores reflect worse endothelial function.
Time frame: 4 weeks (change since baseline)
Change in Oxidized LDL
Change from baseline in Oxidized LDL at 4 weeks, a biomarker of oxidative stress
Time frame: 4 weeks
Change in Myeloperoxidase (MPO)
Change from baseline in Myeloperoxidase (MPO) at 4 weeks, a biomarker of oxidative stress
Time frame: 4 weeks
Change in High Sensitivity C-Reactive Protein (Hs-CRP)
Change from baseline in high sensitivity C-Reactive Protein (hs-CRP) at 4 weeks, a biomarker of inflammation
Time frame: 4 weeks
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