Effect of green tea on plasma leptin and ghrelin levels: A systematic review and meta-analysis of randomized controlled clinical trials

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#catechin #ghrelin #humans #leptin #obesity

Effect of green tea on plasma leptin and ghrelin levels: A systematic review and meta-analysis of randomized controlled clinical trials

Haghighatdoost et al., 2018 | Nutrition | Meta Analysis

Citation

Haghighatdoost Fahimeh, Nobakht M Gh B Fatemeh, Hariri Mitra. Effect of green tea on plasma leptin and ghrelin levels: A systematic review and meta-analysis of randomized controlled clinical trials. Nutrition. 2018-Jan;45:17-23. doi:10.1016/j.nut.2017.06.022

Abstract

OBJECTIVE: The purpose of this study was to conduct a meta-analysis of randomized controlled trials (RCTs) to assess the effect of green tea on serum leptin and ghrelin concentrations. METHODS: We searched PubMed, ISI Web of Science, Scopus, and Google scholar databases up to December 2016. The searches included RCTs conducted in human adults, and studies on the effect of green tea and green tea extract on serum leptin and ghrelin concentrations as outcome variables. Weighted mean differences (WMDs) and standard errors (SEs) of changes in serum ghrelin and leptin levels were calculated. The random effects model was used to derive the summary mean estimates with their corresponding SEs. RESULTS: Eleven RCTs were eligible to be included in the systematic review and the meta-analysis. Our analysis indicated that green tea did not significantly affect leptin and ghrelin concentrations in comparison to placebo (WMD = 1.28 ng/mL, 95% confidence interval: -0.49 to 3.05; P = 0.156, and WMD = 21.49 pg/mL, 95% confidence interval: -40.86 to 83.84; P = 0.499, respectively). However, green tea was associated with an increase in leptin concentration in studies that lasted for more than 12 wk and an increase in ghrelin in women and non-Asians. CONCLUSIONS: Green tea or green tea extract might not be able to change circulatory leptin and ghrelin levels, especially with short-term interventions. More RCTs with longer duration of treatment and higher doses are necessary to assess green tea's effect on fat mass and obesity hormones.

Key Findings

Eleven RCTs were eligible to be included in the systematic review and the meta-analysis. Our analysis indicated that green tea did not significantly affect leptin and ghrelin concentrations in comparison to placebo (WMD = 1.28 ng/mL, 95% confidence interval: -0.49 to 3.05; P = 0.156, and WMD = 21.49 pg/mL, 95% confidence interval: -40.86 to 83.84; P = 0.499, respectively). However, green tea was associated with an increase in leptin concentration in studies that lasted for more than 12 wk and an

Outcomes Measured

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Population

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

MeSH Terms

  • Catechin
  • Ghrelin
  • Humans
  • Leptin
  • Obesity
  • Plant Extracts
  • Randomized Controlled Trials as Topic
  • Sensitivity and Specificity
  • Tea

Evidence Classification

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

Provenance

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