The association between green tea consumption and breast cancer risk: A systematic review and meta-analysis

source extracted confidence: high 2026-04-09
#anticarcinogenic-agents #breast-neoplasms #female #humans #polyphenols

The association between green tea consumption and breast cancer risk: A systematic review and meta-analysis

Najaf et al., 2018 | Phytother Res | Meta Analysis

Citation

Najaf Najafi Mona, Salehi Maryam, ... Khadem-Rezaiyan Majid. The association between green tea consumption and breast cancer risk: A systematic review and meta-analysis. Phytother Res. 2018-Oct;32(10):1855-1864. doi:10.1002/ptr.6124

Abstract

This systematic review and meta-analysis aimed to critically evaluate the relation between green tea (GT) consumption and the risk of breast cancer. Popular electronic databases were systematically searched for papers in English language. All case-control and cohort studies in addition to randomized clinical trials were included if they assessed the chemopreventive effects of GT on breast cancer. The quality of included studies was assessed using the Newcastle-Ottawa and Jadad scale. This systematic review comprised 14 studies: 9 case-control studies, 4 cohort studies, and 1 clinical trial. Odds ratio (OR) in case-control studies suggested that women in the group receiving the highest level of GT had 19% reduction in breast cancer risk compared with those who received the lowest level of GT (summary OR = 0.81, p = .031; 95% CI [0.66, 0.981]; heterogeneity, I2  = 71.53, p < .001, random effect model; 9 studies). OR in cohort studies also showed no significant difference (OR = 0.99, p = .94; 95% CI [0.81, 1.138]; heterogeneity, I2  = 19.06, p = .29; fixed-effect model; 4 studies). According to the only clinical trial, treatment with GT could not alter the mammographic density compared with placebo (26% vs. 25%). It cannot be concluded that GT consumption may decrease the risk of breast cancer. Due to high heterogeneity, a pooled analysis of case-control and cohort studies was not performed.

Key Findings

Due to high heterogeneity, a pooled analysis of case-control and cohort studies was not performed.

Outcomes Measured

  • Requires manual extraction

Population

Field Value
Population See abstract
Sample Size 14
Age Range See abstract
Condition See abstract

MeSH Terms

  • Anticarcinogenic Agents
  • Breast Neoplasms
  • Female
  • Humans
  • Polyphenols
  • Randomized Controlled Trials as Topic
  • Risk Factors
  • 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