Phytonutrient supplements and metabolic biomarkers of cardiovascular disease: An umbrella review of meta‐analyses of clinical trials

Abstract

Phytonutrients exert several pharmacological effects on humans. In this study, we performed an umbrella review of the association of phytonutrient supplements (PNSs) with biomarkers of cardiovascular disease. Relevant published systematic reviews and meta‐analyses of clinical trials were identified by searching PubMed, Embase, and Cochrane Library until July 4, 2020. Weighted mean differences (WMDs) and 95% confidence intervals (CIs) for summarized effects and I2 statistics of heterogeneity were extracted from individual studies or reanalyzed using a random‐effects model. Of the 50 included studies, pooled effects of PNSs on blood pressure, lipid profiles, and glycemic control were reported in 16, 25, and 14 articles, respectively. The findings appeared to be highly heterogeneous among individual trials of included systematic reviews and meta‐analyses. Ginger (WMD = −6.36 mmHg, 95% CI = −11.27, −1.46) and Hibiscus sabdariffa (WMD = −7.58 mmHg, 95% CI = −9.69, −5.46) were associated with lowered systolic blood pressure, whereas Aloe vera, Nigella sativa, and spirulina were associated with beneficial effects on both lipid profiles and glycemic control. In summary, this umbrella review has provided up‐to‐date evidence for the effect of PNSs on biomarkers related to hypertension, dyslipidemia, and diabetes. The results must be interpreted with caution due to potential heterogeneity.

Appraisal methods and outcomes of AMSTAR 2 assessments in overviews of systematic reviews of interventions in the cardiovascular field: A methodological study

“…Moreover, we conducted an unplanned sensitivity analysis after excluding an overview 34 with less conservative assessments, assigning exclusively moderate or high ratings to the 48 included SRs, which in turn were reclassified as of “Critically low” or “Low” confidence by the official AMSTAR 2 online tool.…”

Ginger Update

“…Based on a limited number of RCTs, there is some recent evidence that ginger supplementation can favorably affect systolic blood pressure and body mass index, but less so for diastolic blood pressure, BW, and waist-to-height ratio 57–59,64,80,85 …”

“…The inconsistencies among individual trial outcomes make it unclear what doses and durations of ginger might be efficacious in improving the signs and symptoms of metabolic syndrome. Moreover, the magnitude of ginger-associated changes varied among analyses, making the clinical meaningfulness of the outcomes unclear 10,85,86 . The interpretation of findings can be affected by different types and preparation methods of ginger supplements, method of daily administration, length of treatment, and the type and severity of disease 87 .…”

“…83,84 Based on a limited number of RCTs, there is some recent evidence that ginger supplementation can favorably affect systolic blood pressure and body mass index, but less so for diastolic blood pressure, BW, and waist-toheight ratio. [57][58][59]64,80,85 The inconsistencies among individual trial outcomes make it unclear what doses and durations of ginger might be efficacious in improving the signs and symptoms of metabolic syndrome. Moreover, the magnitude of gingerassociated changes varied among analyses, making the clinical meaningfulness of the outcomes unclear.…”

“…Moreover, the magnitude of gingerassociated changes varied among analyses, making the clinical meaningfulness of the outcomes unclear. 10,85,86 The interpretation of findings can be affected by different types and preparation methods of ginger supplements, method of daily administration, length of treatment, and the type and severity of disease. 87 One analysis concluded that population sample size and duration of intake were critical factors in influencing the effect of ginger on type 2 diabetes.…”