Tea Consumption and Risk of Chronic Obstructive Pulmonary Disease in Middle-Aged and Older Singaporean Adults
Received 27 July 2020
Accepted for publication 7 October 2020
Published 7 January 2021 Volume 2021:16 Pages 13—23
Checked for plagiarism Yes
Review by Single anonymous peer review
Peer reviewer comments 2
Editor who approved publication: Dr Richard Russell
Tze Pin Ng,1 Qi Gao,1 Xinyi Gwee,1 Denise QL Chua,1 Wan C Tan2
1Gerontology Research Programme, Department of Psychological Medicine, National University of Singapore, Singapore; 2Centre for Heart Lung Innovation, Department of Medicine, University of British Columbia, Vancouver, BC, Canada
Correspondence: Tze Pin Ng
Gerontology Research Programme, Department of Psychological Medicine, National University of Singapore, NUHS Tower Block, 9 th Floor, 1E Kent Ridge Road, 119228, Singapore
Fax +65-67772191 Email firstname.lastname@example.org
Objective: The anti-oxidant and anti-inflammatory actions of phytochemicals and the smooth muscle relaxant actions of theophylline present in tea may confer pulmonary protection and reduce COPD risk. We investigated tea consumption (black, oolong, or green) association with COPD risks in a population-based cohort study of older adults aged ≥ 55.
Methods: GOLD criteria was used to identify prevalent and incident cases of COPD (FEV1/FVC < 0.70) among 4617 participants and 920 participants free of COPD at baseline who were assessed at follow-up 4.5 years later.
Results: Prevalent cases of COPD consumed less tea than their non-COPD counterparts. Estimated odds ratio (OR) and 95% confidence intervals (95% CI) of association with prevalent COPD, adjusted for age, sex, ethnicity, housing type, smoking, alcohol, physical activity and BMI declined across tea consumption levels (p-trend=0.048), and was lowest for ≥ 3 cups/day (OR=0.77, 95% CI=0.61– 0.96). The cumulated incidence of COPD declined across tea consumption categories (p-trend=0.012) and the lowest OR of association (OR=0.35, 95% CI=0.17– 0.69) with consuming ≥ 3 cups/day after co-variate adjustment.
Conclusion: Different kinds of tea showed similar non-significant trends of associations but appeared to be strongest for green tea. Tea consumption in this Asian population was associated with lowered COPD prevalence and incidence.
Keywords: phytochemical, polyphenols, theophylline, epidemiological, longitudinal