Effects of Coffee and Tea Consumption on Glucose Metabolism: A Systematic Review and Network Meta-Analysis

source extracted confidence: high 2026-04-09
#coffee #diabetes-mellitus #glucose #humans #tea

Effects of Coffee and Tea Consumption on Glucose Metabolism: A Systematic Review and Network Meta-Analysis

Kondo et al., 2018 | Nutrients | Systematic Review

Citation

Kondo Yoshinobu, Goto Atsushi, ... Noda Mitsuhiko. Effects of Coffee and Tea Consumption on Glucose Metabolism: A Systematic Review and Network Meta-Analysis. Nutrients. 2018-Dec-27;11(1). doi:10.3390/nu11010048

Abstract

Prospective cohort studies have described an association between coffee or tea consumption and the risk of developing diabetes. However, whether coffee or tea improves glucose metabolism remains uncertain. We investigated the effect of coffee and tea on glucose metabolism by conducting a systematic review and meta-analysis of randomized controlled trials. Electronic databases were searched for articles published up 19 February 2017. The primary endpoint was the mean difference in post-intervention fasting blood glucose (FBG) levels between the groups. Of 892 citations screened, 27 studies (1898 participants) were included in our meta-analysis. A network meta-analysis suggested that green tea, but not caffeinated/decaffeinated coffee or black tea, may reduce FBG levels, compared with placebo/water (-2.10 mg/dL; 95% confidence interval (CI), -3.96 to -0.24 mg/dL; p = 0.03; moderate quality of evidence). In a subgroup analysis, the effect of green tea on FBG levels was statistically significant only in studies with a mean age of < 55-years-old or Asian-based studies. The oolong tea group also showed a significant decrease in FBG, but the quality of evidence was very low. In conclusion, green tea consumption might decrease FBG levels, especially in < 55-year-olds or Asian-based populations.

Key Findings

In conclusion, green tea consumption might decrease FBG levels, especially in < 55-year-olds or Asian-based populations.

Outcomes Measured

  • Requires manual extraction

Population

Field Value
Population See abstract
Sample Size 1898
Age Range See abstract
Condition diabetes

MeSH Terms

  • Coffee
  • Diabetes Mellitus
  • Glucose
  • Humans
  • Tea

Evidence Classification

  • Level: Systematic Review
  • Publication Types: Journal Article, Systematic Review, Network Meta-Analysis
  • Vertical: green-tea

Provenance

Source extracted via PubMed E-utilities API on 2026-04-09