Association of Lung Cancer and Tea-Drinking Habits of Different Subgroup Populations: Meta-Analysis of Case-Control Studies and Cohort Studies

Zijun Guo; Mei Jiang; Wenting Luo; Peiyan Zheng; Huimin Huang; Baoqing Sun

Association of Lung Cancer and Tea-Drinking Habits of Different Subgroup Populations: Meta-Analysis of Case-Control Studies and Cohort Studies

Iran J Public Health. 2019 Sep;48(9):1566-1576.

Authors

Zijun Guo¹, Mei Jiang¹, Wenting Luo¹, Peiyan Zheng¹, Huimin Huang¹, Baoqing Sun¹

Affiliation

¹ Guangzhou Institute of Respiratory Disease, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, China.

PMID: 31700812
PMCID: PMC6825660

Abstract

Background: We aimed to investigate the association between lung cancer and tea-drinking habits of different subgroup populations.

Methods: Systematic search of the PubMed, Web of Science, China National Knowledge Infrastructure (CNKI) and Sinomed databases from database construction until January 2017 for English and Chinese language articles on association of lung cancer and tea drinking. Meta-analysis was used to calculate the combined odds ratio (OR) value and its 95% confidence interval (95% CI). The Newcastle-Ottawa scale was used to evaluate the quality of the studies and Q-test and I₂ was used for heterogeneity testing.

Results: Forty two papers were included, 30 case-control studies included 14578 lung cancer patients and 180574 controls, 12 cohort studies included 543825 subjects, of which the outcome was 5085 with lung cancer. Tea drinkers were found to have a decreased OR of lung cancer compared with non-tea drinkers (OR 0. 80, 95% CI: 0. 73, 0. 87). Consumption of green, black or unspecified tea has a protective effect compared with not drinking tea at all. Increased intake of green tea to 7. 5 g per day can further reduce the OR of lung cancer (OR 0. 69, 95% CI: 0. 48-0. 98). Tea consumption had a protective effect against lung cancer in non-smokers, Further analysis found that drinking of one or more cups of tea a day has a protective effect on smokers (OR 0. 79, 95% CI: 0. 64-0. 96).

Conclusion: Tea drinking could be a protective factor in lung cancer.

Keywords: Case-control studies; Cohort studies; Lung cancer; Meta-analysis; Tea.

Publication types

Review