Objective To prospectively examine the association between tea consumption and the risk of ischaemic heart disease (IHD).
Methods Prospective study using the China Kadoorie Biobank; participants from 10 areas across China were enrolled during 2004–2008 and followed up until 31 December 2013. After excluding participants with cancer, heart disease and stroke at baseline, the present study included 199 293 men and 288 082 women aged 30–79 years at baseline. Information on IHD incidence was collected through disease registries and the new national health insurance databases.
Results During a median follow-up of 7.2 years, we documented 24 665 (7.19 cases/1000 person-years) incident IHD cases and 3959 (1.13 cases/1000 person-years) major coronary events (MCEs). Tea consumption was associated with reduced risk of IHD and MCE. In the whole cohort, compared with participants who never consumed tea during the past 12 months, the multivariable-adjusted HRs and 95% CIs for less than daily and daily tea consumers were 0.97 (0.94 to 1.00) and 0.92 (0.88 to 0.95) for IHD, 0.92 (0.85 to 1.00) and 0.90 (0.82 to 0.99) for MCE. No linear trends in the HRs across the amount of tea were observed in daily consumers for IHD and MCE (PLinear >0.05). The inverse association between tea consumption and IHD was stronger in rural (PInteraction 0.006 for IHD, <0.001 for MCE), non-obese (PInteraction 0.012 for MCE) and non-diabetes participants (PInteraction 0.004 for IHD).
Conclusions In this large prospective study, daily tea consumption was associated with a reduced risk of IHD.
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Collaborators The members of steering committee and collaborative group are listed in the only online supplemental material (or Acknowledgements).
Contributors XL and CY contributed equally. LL, ZC and JC obtained funding. JL and LL conceived and designed the study. YG, ZB, LY, YC, XR, GJ and ZC acquired the data. XL, JS and CY analysed the data. XL and CY drafted the manuscript. JL and LL contributed to the interpretation of the results and critical revision of the manuscript for important intellectual content and approved the final version of the manuscript. All authors reviewed and approved the final abstract.
Funding This work was supported by grants (81390544, 81390541) from the National Natural Science Foundation of China. The CKB baseline survey and the first resurvey were supported by a grant from the Kadoorie Charitable Foundation in Hong Kong. The long-term follow-up is supported by grants from the UK Wellcome Trust (088158/Z/09/Z, 104085/Z/14/Z).
Competing interests None declared.
Patient consent Obtained.
Ethics approval The Ethical Review Committee of the Chinese Center for Disease Control and Prevention (Beijing, China) and the Oxford Tropical Research Ethics Committee, University of Oxford (UK).
Provenance and peer review Not commissioned; externally peer reviewed.
Data sharing statement See study website (www.ckbiobank.org) for access policy and procedures.
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