Journal of General Internal Medicine

, Volume 24, Issue 5, pp 557–562

Tea Consumption and Risk of Type 2 Diabetes: A Meta-Analysis of Cohort Studies

Authors

  • Yali Jing
    • Department of EndocrinologyDrum Tower Clinical Medical College of Nanjing Medical University
  • Guanjun Han
    • Department of EndocrinologyDrum Tower Clinical Medical College of Nanjing Medical University
  • Yun Hu
    • Department of Endocrinology, Affiliated Drum Tower HospitalMedical College of Nanjing University
  • Yan Bi
    • Department of Endocrinology, Affiliated Drum Tower HospitalMedical College of Nanjing University
  • Lirong Li
    • Department of Endocrinology, Affiliated Drum Tower HospitalMedical College of Nanjing University
    • Department of EndocrinologyDrum Tower Clinical Medical College of Nanjing Medical University
Original Article

DOI: 10.1007/s11606-009-0929-5

Cite this article as:
Jing, Y., Han, G., Hu, Y. et al. J GEN INTERN MED (2009) 24: 557. doi:10.1007/s11606-009-0929-5

ABSTRACT

BACKGROUND

Tea consumption has been extensively studied in relation to various diseases, several epidemiologic studies have been performed to investigate the association of tea consumption with type 2 diabetes; however, the results of these studies were not entirely consistent.

OBJECTIVE

To conduct a meta-analysis of studies that assessed the association of tea consumption and the risk of type 2 diabetes.

RESEARCH DESIGN AND METHODS

We performed a systematic literature search through November 2008 in PUBMED, MEDLINE, EMBASE, and Cochrane Database of Systematic Reviews. The search was limited to English-language studies. Studies were excluded if they were type 1 diabetes, animal studies. Nine cohort studies were identified by two authors, and summary relative risks (RRs) were calculated using a random-effects model.

RESULTS

We identified nine cohort studies, including 324,141 participants and 11,400 incident cases of type 2 diabetes with follow-up ranging from 5 to 18 years. The summary adjusted RR did not show that tea consumption was associated with a reduced type 2 diabetes risk (RR, 0.96; 95% confidence interval (CI), 0.92–1.01). Evidence from the results of our stratified analyses revealed that tea consumption ≥4 cups per day (RR, 0.8; 95% CI, 0.7–0.93) might play a role in the prevention of type 2 diabetes. However, no statistically significant association was observed for sex and the follow-up durations stratified between tea consumption and type 2 diabetes.

CONCLUSIONS

This meta-analysis indicates that tea consumption ≥4 cups per day may lower the risk of type 2 diabetes.

KEY WORDS

type 2 diabetesteameta-analysis

Copyright information

© Society of General Internal Medicine 2009