Enhancing the cardiovascular protective effects of a healthy dietary pattern with wolfberry (Lycium barbarum): A randomized controlled trial

Abstract

Background: The consumption of wolfberry (Lycium barbarum), a rich source of carotenoids and bioactive polysaccharides, may serve as a potential dietary strategy for cardiovascular disease (CVD) risk management although limited studies examined its effects as whole fruits.

Objectives: To investigate the impact of wolfberry consumption as part of a healthy dietary pattern on vascular health-related outcomes and classical CVD risk factors in middle-aged and older adults in Singapore.

Methods: This is a 16-week, parallel design, randomized controlled trial. All participants (n = 40) received dietary counselling to follow healthy dietary pattern recommendations with the wolfberry group given additional instructions to cook and consume 15 g/d whole, dried wolfberry with their main meals. Biomarkers of vascular function (flow-mediated dilation, plasma total nitrate/nitrite, endothelin-1, and intercellular adhesion molecule-1), vascular structure (carotid intima-media thickness) and vascular regeneration (endothelial progenitor cell count, plasma angiopoietin 1 and angiopoietin 2), were assessed at baseline and postintervention. Serum lipid-lipoproteins and blood pressure were evaluated every 4 weeks.

Results: All participants showed an improved compliance toward the healthy dietary pattern. This was coupled with marked rises in total nitrate/nitrite concentrations (mean change wolfberry: 3.92 ± 1.73 nmol/mL; control: 5.01 ± 2.55 nmol/L) and reductions in endothelin-1 concentrations (wolfberry: -0.19 ± 0.06 pg/mL; control: -0.15 ± 0.08 pg/mL). Compared with the control which depicted no changes from baseline, the wolfberry group had a significantly higher HDL cholesterol (0.08 ± 0.04 mmol/L), as well as lower Framingham predicted long-term CVD risk (-0.8 ± 0.5%) and vascular age (-1.9 ± 1.0 y) postintervention. No differences were observed in the other vascular health-related outcomes.

Conclusions: In middle-aged and older adults, adherence to a healthy dietary pattern improves vascular tone. Incorporating wolfberry to the diet further improves blood lipid-lipoprotein profile and may lower long-term CVD risk. This study was registered at clinicatrials.gov as NCT03535844.

Keywords: Lycium barbarum; cardiovascular disease; carotid intima-media thickness; endothelial progenitor cells; endothelin-1; flow-mediated dilation; healthy diet; lipoprotein; middle-aged; nitric oxide.