The effect of polyphenol-rich chardonnay seed supplements on peripheral endothelial function

Objective Peripheral endothelial dysfunction (PED) is associated with major adverse cardiovascular events. Similar to cardio-protective Mediterranean diet, Chardonnay seeds are rich in polyphenols, fibers, and grape seed oil. In this randomized double-blinded trial, we investigated safety and incremental benefit of Chardonnay seed polyphenols-rich (PR), compared to polyphenols-free (PF), supplements on PED. Methods 89 patients with PED [reactive hyperemia-peripheral arterial tonometry (RH-PAT) index ≤ 2) were randomized 1:1 to 4.8 g (6 capsules)/day PR or PF for 4 months. PR and PF capsules had equal amounts of seed oil (~ 7% capsule weight), fibers, and carbohydrates, but only PR capsules contained polyphenols (~ 11% capsule weight). Baseline and follow-up RH-PAT indices (primary endpoint) and endothelial progenitor cells (EPC) levels were measured. Patients were asked to maintain their regular diet and exercise habits during study period. Results Baseline RH-PAT indices, demographics, lab values, and EPC levels were similar between groups. No significant adverse reactions to PR or PF were reported. Follow-up RH-PAT indices significantly increased ( p < 0.05 vs. baseline) in both groups to similar extent (31 ± 39% PR vs. 49 ± 53% PF, p = 0.09). Circulating CD34 + EPCs equally increased (median + 55% vs. + 54%, p = 0.94) in PR and PF groups, respectively. Conclusion PR and PF Chardonnay seed supplements were safe and improved peripheral endothelial function to similar extent in PED patients. However, there were no incremental benefits of PR over PF on RH-PAT indices or CD34 + EPC levels. Chardonnay seed supplements role in primary prevention of atherosclerosis, as add-on to healthy lifestyle and guidelines directed medical therapy, should be further explored. ClinicalTrials.gov identifier (NCT number) NCT02093455