Cardiovascular disease risk reduction with wolfberry consumption: a systematic review and meta-analysis of randomized controlled trials

PURPOSE

Wolfberry is rich in bioactive compounds which may lower cardiovascular disease risk. This meta-analysis aimed to systematically evaluate the effects of wolfberry-based randomized controlled trials (RCTs) on overall cardiovascular health.

METHODS

Four online databases (PubMed, CINAHL Plus, Medline and Cochrane Library) were searched to shortlist relevant RCTs. Outcomes of interests included blood lipids and lipoproteins, blood pressure, biomarkers of oxidative stress, inflammation and other cardiovascular health-related indicators. Random-effects models were used to provide a weighted mean difference (WMD) and/or Hedges' g for quantitative synthesis. This was coupled with subcategory analyses which stratified RCTs according to the form in which wolfberry was administered (whole wolfberry versus wolfberry extract).

RESULTS

From the 785 articles identified, 10 were selected for meta-analysis. Compared to the control, groups which consumed wolfberry showed a reduction in blood triglycerides [WMD_pooled (95% confidence interval): - 0.14 (- 0.19, - 0.09) mmol/L] and increased blood high-density lipoprotein cholesterol [WMD_pooled: 0.06 (0.02, 0.09) mmol/L]. Notably, effects for both triglycerides [WMD_whole: - 0.14 (- 0.19, - 0.09) mmol/L; WMD_extract: - 0.07 (- 0.30, 0.16) mmol/L] and high-density lipoprotein cholesterol [WMD_whole: 0.06 (0.02, 0.09) mmol/L; WMD_extract: 0.05 (- 0.02, 0.13) mmol/L] were more prominent after whole wolfberry interventions. Additionally, blood malondialdehyde equivalents were also significantly decreased in wolfberry consuming groups [Hedges' g_pooled: - 1.45 (- 2.75, - 0.16)]. No changes were observed for the other lipids and lipoproteins as well as blood pressure.

CONCLUSIONS

Wolfberry consumption is effective in improving blood lipids and lipoproteins profile and lowering oxidative stress. This supports the incorporation of wolfberry, particularly as whole fruits, into dietary patterns targeted at improving cardiovascular health.

A Systematic Review and Meta-Analysis of the Impact of Different Intensity of Dietary Counselling on Cardiometabolic Health in Middle-Aged and Older Adults

Dietary counselling has been identified as one of the nutritional strategies to alleviate cardiometabolic health conditions. Its effectiveness however may vary due to factors such as intensity level and provider while this has not been comprehensively studied. This systematic review and meta-analysis aimed to assess the effects of dietary counselling on the cardiometabolic health in middle-aged and older adults and the sub-group analyses with dietary counselling intensity and the provider were also assessed. Four databases including PubMed, CINAHL Plus with Full Text, Cochrane Library and EMBASE were systematically searched. Data from 22 randomised controlled trials (RCTs) were compiled and those from 9 RCTs were utilised for meta-analysis. Dietary counselling lowered total cholesterol (TC) and fasting blood sugar (FBS) but had no impact on triglycerides (TG) and low-density lipoprotein (LDL). Sub-group analysis revealed significant lowering effect of high intensity dietary counselling for TG (weighted mean difference (WMD): −0.24 mmol/L, 95% confidence intervals (CIs): −0.40 to −0.09), TC (WMD: −0.31 mmol/L, 95% CIs: −0.49 to −0.13), LDL (WMD: −0.39 mmol/L, 95% CIs: −0.61 to −0.16) and FBS (WMD: −0.69 mmol/L, 95% CIs: −0.99 to −0.40) while medium or low intensity dietary counselling did not show favouring effects. Counselling provider showed differential responses on cardiometabolic health between dietitian and all other groups. The findings from this systematic review and meta-analysis suggest that dietary counselling is a beneficial dietary strategy to improve cardiometabolic health in middle-aged and older adults with the emphasis on the counselling intensity.

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

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.

The Influence of Different Foods and Food Ingredients on Acute Postprandial Triglyceride Response: A Systematic Literature Review and Meta-Analysis of Randomized Controlled Trials

The use of postprandial triglyceride (ppTG) as a cardiovascular disease risk indicator has gained recent popularity. However, the influence of different foods or food ingredients on the ppTG response has not been comprehensively characterized. A systematic literature review and meta-analysis was conducted to assess the effects of foods or food ingredients on the ppTG response. PubMed, MEDLINE, Cochrane, and CINAHL databases were searched for relevant acute (<24-h) randomized controlled trials published up to September 2018. Based on our selection criteria, 179 relevant trials (366 comparisons) were identified and systematically compiled into distinct food or food ingredient categories. A ppTG-lowering effect was noted for soluble fiber (Hedges' giAUC = -0.72; 95% CI: -1.33, -0.11), sodium bicarbonate mineral water (Hedges' gAUC = -0.42; 95% CI: -0.79, -0.04), diacylglycerol oil (Hedges' giAUC = -0.38; 95% CI: -0.75, -0.00), and whey protein when it was contrasted with other proteins. The fats group showed significant but opposite effects depending on the outcome measure used (Hedges' giAUC = -0.32; 95% CI: -0.61, -0.03; and Hedges' gAUC = 0.16; 95% CI: 0.06, 0.26). Data for other important food groups (nuts, vegetables, and polyphenols) were also assessed but of limited availability. Assessing for oral fat tolerance test (OFTT) recommendation compliance, most trials were ≥4 h long but lacked a sufficiently high fat challenge. iAUC and AUC were more common measures of ppTG. Overall, our analyses indicate that the effects on ppTG by different food groups are diverse, largely influenced by the type of food or food ingredient within the same group. The type of ppTG measurement can also influence the response.

Enhancing the Cardiovascular Protective Effects of a Healthy Dietary Pattern with Wolfberry (Lycium barbarum): A Randomized Controlled Trial

Objectives

The study aimed to investigate the impact of wolfberry (Lycium barbarum) consumption as part of a healthy dietary pattern on cardiovascular health in Singaporean middle-aged and older adults. It was hypothesized that the consumption of wolfberry could further enhance the cardiovascular protective effects of a healthy dietary pattern.

Methods

This was a 16 week, parallel design, randomized controlled trial where 40 Singaporean men and women (aged 50 to 64 years) received dietary counselling to follow a healthy dietary pattern either with or without 15 g/day of dried whole wolfberry, cooked and consumed as part of their meals. Blood pressure, serum lipid-lipoprotein concentrations and dietary compliance using 3-day food records were monitored every 4 weeks. Further evaluation of cardiovascular disease (CVD) biomarkers, broadly classified as serological (total nitrate/nitrite, endothelin-1, intercellular adhesion molecule-1, angiopoietin-1, angiopoietin-2 and von-Willebrand factor), structural (carotid intima-media thickness using B-mode ultrasonography) and functional (flow-mediated dilation using B-mode ultrasonography and circulating endothelial progenitor cells (CD34+/KDR+) by fluorescence-activated cell sorting) were analyzed before and after intervention.

Results

Adherence to a healthy dietary pattern contributed to a time dependent effect on both the plasma total nitrate/nitrite (P &lt; 0.01) and plasma endothelin-1 (P &lt; 0.005) which were raised and lowered respectively at week 16. However, changes were significant only in the wolfberry group (total nitrate/nitrite: 15.9 ± 1.8 to 19.4 ± 2.2 μmol/L, P &lt; 0.05; endothelin-1: 1.31 ± 0.12 to 1.11 ± 0.10 ng/L, P &lt; 0.01) and not in the control group. Moreover, a significant increase in serum high density lipoprotein (HDL) cholesterol was also detected solely in the wolfberry group (1.56 ± 0.10 to 1.65 ± 0.10 mmol/L, P &lt; 0.05). The other serological, structural and functional biomarkers of cardiovascular health showed no observable change after the intervention.

Conclusions

Incorporating wolfberry to your daily meals may augment the cardiovascular protective benefits of a healthy dietary pattern by improving the regulation of vascular tone and plasma lipid-lipoprotein profile in Singaporean middle-aged and older adults.

Funding Sources

Ministry of Education, Singapore.