Tea consumption, incidence and long-term prognosis of a first acute myocardial infarction – The SHEEP study

Abstract

Results of previous studies on tea consumption and incidence or prognosis of acute myocardial infarction (AMI) are conflicting. The aim of the present study was to examine the potential role of tea consumption in the previous 12 months in primary and secondary prevention of AMI. We studied a total of 1340 individuals with a first non-fatal AMI and 2303 frequency matched control participants on age, gender and hospital catchment area including querying their tea consumption over the previous 12 months. The cohort of AMI cases was then followed for total and cardiac mortality and for non-fatal cardiovascular events with national registers over 8 years. Estimates of relative risks for a first AMI were based on odds ratios from unconditional logistic regression and Cox proportional hazards models were used to examine the prognostic importance of tea consumption in the cohort of cases. The prevalence of daily tea consumption was 20.5% among cases and 21.5% among controls. Tea consumption was associated with a lower risk for a first AMI with adjustment for matching criteria alone, with an odds ratio of 0.78 (95% confidence interval, 0.64-0.95) comparing those who consumed tea daily to those never consuming tea. However, in multivariable adjusted model there was no evidence for an association, the corresponding odds ratio was 1.08(0.86-1.36). There was also no association between tea consumption and cardiac mortality and non-fatal cardiovascular events, with a corresponding adjusted hazard ratio of 0.99(0.77-1.27). In this epidemiological study, greater tea consumption in the previous year was associated with a lower risk of AMI. However, a clear association between tea consumption and the incidence or prognosis of AMI was not demonstrated, probably because of tea drinkers having a healthier lifestyle.