Effect Of Berries On Metabolic Syndrome:a Systematic Review And Meta-Analysis

Background: Berries are considered as some of the best dietary sources of bioactive compounds which promote human health.The previous researches in animal and human found the health benefits of berries in regard to prevention and treatment of obesity,hypertension,type2 diabetes,dyslipidemia.Recent studies have investigated the association between the consumption of berry and metabolic syndrome,but the results remains inconclusive.Methods: We searched the PubMed,Embase,Web of Science,and the Cochrane databases for relevant studies,ending in March 2017 to evaluate the effects of berry supplementation on metabolic syndrome.We used pooled standardized mean difference(SMD)with 95% confidence interval(CI)to assess the effect of berries on metabolic syndrome.Results: Nine randomized controlled trials with 398 participants(209in intervention and 189 in control groups)were included.The results showed that berry supplementation has significant effects on changes in serum total cholesterol(SMD:-0.38,95% CI: [-0.59,-0.16],p: 0.001)and low-density lipoprotein cholesterol(SMD:-0.26,95% CI: [-0.47,-0.05],p:0.017)relative to baseline compared with the control groups.But,no significant effects on systolic blood pressure,diastolic blood pressure,fasting glucose,triglycerides and high-density lipoprotein cholesterol werenoted compared to the control groups.Conclusions: Berry supplementation may protect patients with metabolic syndrome through improving serum lipid levels.Further well-designed RCTs with larger sample sizes are required to confirm the effectiveness of berry supplementation for metabolic syndrome.