The effects of green coffee extract supplementation on glycemic indices and lipid profile in adults: a systematic review and dose-response meta-analysis of clinical trials

Abstract

Background: The role of coffee consumption in the risk of cardiovascular diseases has been debated for many years. The current study aimed to summarize earlier evidence on the effects of green coffee extract (GCE) supplementation on glycemic indices and lipid profile. Methods: We searched available online databases for relevant clinical trials published up to October 2019. All clinical trials investigating the effect of GCE supplementation, compared with a control group, on fasting blood glucose (FBG), serum insulin, total cholesterol (TC), triglyceride (TG), low-density lipoprotein (LDL), and high-density lipoprotein (HDL) were included. Overall, 14 clinical trials with a total sample size of 766 participants were included in the current meta-analysis. Results: We found a significant reducing effect of GCE supplementation on FBG (weighted mean difference (WMD):-2.35, 95% CI: − 3.78, − 0.92 mg/dL, P = 0.001) and serum insulin (WMD:-0.63, 95% CI: − 1.11, − 0.15 μU/L, P = 0.01). With regard to lipid profile, we observed a significant reduction only in serum levels of TC following GCE supplementation in the overall meta-analysis (WMD:-4.51, 95% CI: − 8.39, − 0.64, P = 0.02). However, subgroup analysis showed a significant reduction in serum TG in studies enrolled both genders. Also, such a significant reduction was seen in serum levels of LDL and HDL when the analyses confined to studies with intervention duration of ≥8 weeks and those included female subjects. In the non-linear dose-response analyses, we found that the effects of chlorogenic acid (CGA) dosage, the main polyphenol in GCE, on FBG, TG and HDL were in the nonlinear fashions.

Green Coffee Bean Extract Normalize Obesity-Induced Alterations of Metabolic Parameters in Rats by Upregulating Adiponectin and GLUT4 Levels and Reducing RBP-4 and HOMA-IR

“…Studies indicate that polyphenols containing plants like green coffee may be used to treat various health problems, including metabolic syndrome. The beneficial health effects of GCBE are attributed to the antioxidant activity of numerous polyphenol components and a significant contribution of CGA [ 11 ]. This research was done to elucidate the effect of 200 mg of GCBE/kg BW for eight weeks on obesity, the alleviation of insulin resistance, and inflammation resulting from obesity.…”

“…Coffee is the most popular drink in the world, and it contains a variety of phytochemicals. Coffee consumption was shown to be beneficial for a variety of health problems, including metabolic syndrome (Mets), vascular function, and type 2 diabetes (T2DM) [ 11 ]. Green coffee, which refers to unroasted coffee beans [ 12 ], has been suggested to have the ability to prevent Mets [ 13 ] and T2DM [ 14 ].…”

“…Phenolic compounds, particularly chlorogenic acids (CGA), are phytochemicals abundantly found in coffee [ 11 ]. Green coffee bean extract (GCBE) is isolated from unroasted green coffee beans, resulting from a significant proportion of CGA depletion during the roasting process [ 19 ].…”

Effect of vitamin E intake on glycemic control and insulin resistance in diabetic patients: an updated systematic review and meta-analysis of randomized controlled trials

“…An Excel-based form was designed to extract data from each article. This form was used in our previous meta-analyses [3,31,32] and was revised based on the current title. We extracted the following data: name of the first author, publication year, demographic characteristics (mean age and sex distribution), design, sample size (control and intervention groups), type of vitamin E prescribed, vitamin E dosage, duration of the intervention, mean changes and their SDs of outcomes (glycemic and insulin indices) for the intervention and control groups, and the confounding variables adjusted in the analyses.…”

The Analysis of the Chlorogenic Acid in the Ethanol Fraction of Robusta Coffee Beans and Its Effect on Glucose Levels in Wistar Rats

“…Chlorogenic acid at a dose of 5mg/kg BW may provide antidiabetic potential in rats [17,18]. Based on the elaboration above, it is necessary to carry out a study on the effect of the provision of the remaining fraction of Robusta coffee (Coffea canephora L.) beans to reduce blood glucose levels in Wistar rats (Rattus norvegicus) [13,[19][20][21].…”