Effects of Walnuts on Vascular Function and Platelet Reactivity in Postmenopausal Women with Hypercholesterolemia

Abstract

Walnuts contain a number of phenolic acids, polyphenols and lipids that may benefit cardiovascular health. We examined the effects of acute (4 hours) and short‐term (4 weeks) walnut intake on select cardiovascular outcome measures. Thirty‐six hypercholesterolemic postmenopausal women were randomly assigned to consume 5 or 40 g of walnuts daily for 4 weeks in a parallel‐arm design. Outcomes were measured after an overnight fast, and 4 hours after walnut intake on the first day of the study (V1) and after 4 weeks (V2) and included microvascular function as assessed by peripheral arterial tonometry (PAT), platelet function (PFA‐100), and serum lipids. Data are presented as mean ± SD. No significant changes in PAT were noted after 5 g of walnut intake. However, 40 g of walnut intake for 4 weeks was associated with an increased PAT response after an overnight fast (V1: 2.32 ± 0.39 vs. V2: 2.70 ± 0.31; p=0.008). An increase in PAT was also observed 4 hours after 40 g of walnut intake on V1 (2.32 ± 0.39 vs. 2.82 ± 0.39; p=0.001), but not on V2. LDL concentrations were decreased 4 weeks after 40 g/day of walnut intake (V1: 154.76 ± 16.79 mg/dL vs. V2: 146.06 ± 17.33 mg/dL). No significant changes were found in platelet function or other lipids in either group. The results suggest that the chronic consumption of 40 g of walnuts can result in positive vascular effects. This work was supported by the California Walnut Commission.Grant Funding Source: The California Walnut Commission