Beneficial effects of blueberry supplementation on the components of metabolic syndrome: a systematic review and meta-analysis

Metabolic syndrome (MetS) is a combination of interconnected disorders that puts a heavy burden on society. This study investigated the impact of blueberry (BB) supplementation on components of MetS. A systematic search for studies in Embase, Science Direct, Cochrane and PubMed was done. Interventions for at least 2 weeks and studies which investigated the effects of BB on components of MetS in human subjects were included. 25 studies were eligible for inclusion in the review. 21 studies were included in the meta-analysis and the remaining 4 studies in the systematic review. The time range of the assessed studies was from 2007 to 2021. The results of the meta-analysis demonstrated that BB had no significant effect on waist circumference, body mass index (BMI), glycated hemoglobin (HbA1C), glucose level and homeostatic model assessment for insulin resistance (HOMA-IR); however, studies showed a significant improvement in systolic and diastolic blood pressure, triglycerides, total cholesterol, low-density lipoproteins (LDL), high-density lipoproteins (HDL) and insulin levels. In conclusion, the data in this meta-analysis show that BB supplementation is a beneficial option for the management of MetS in humans.