Coffee and tea are 2 of the most commonly consumed beverages in the world. The association of coffee and tea intake with coronary artery calcium and major adverse cardiovascular events remains uncertain.
Methods
We examined 6508 ethnically diverse participants with available coffee and tea data from the Multi-Ethnic Study of Atherosclerosis. Intake for each was classified as never, occasional (<1 cup per day), and regular (ā„1 cup per day). A coronary artery calcium progression ratio was derived from mixed effect regression models using loge(calcium score+1) as the outcome, with coefficients exponentiated to reflect coronary artery calcium progression ratio versus the reference. Cox proportional hazards analyses were used to evaluate the association between beverage intake and incident cardiovascular events.
Results
Over a median follow-up of 5.3 years for coronary artery calcium and 11.1 years for cardiovascular events, participants who regularly drank tea (ā„1 cup per day) had a slower progression of coronary artery calcium compared with never drinkers after multivariable adjustment. This correlated with a statistically significant lower incidence of cardiovascular events for ā„1 cup per day tea drinkers (adjusted hazard ratio 0.71; 95% confidence interval 0.53-0.95). Compared with never coffee drinkers, regular coffee intake (ā„1 cup per day) was not statistically associated with coronary artery calcium progression or cardiovascular events (adjusted hazard ratio 0.97; 95% confidence interval 0.78-1.20). Caffeine intake was marginally inversely associated with coronary artery calcium progression.
Conclusions
Moderate tea drinkers had slower progression of coronary artery calcium and reduced risk for cardiovascular events. Future research is needed to understand the potentially protective nature of moderate tea intake.
Coffee and tea are 2 of the most commonly consumed beverages in the world.1Ā Caffeine, the most studied active compound in coffee and tea, has well-known short-term cardiovascular effects, including increased plasma renin levels, peripheral vasoconstriction, increased blood pressure, and cardiac arrhythmias.2,Ā 3,Ā 4,Ā 5Ā Despite these effects, coffee intake is associated with a lower incidence of diabetes and favorable effects on endothelial function.6,Ā 7Ā The association of coffee and tea intake with clinical cardiovascular outcomes, however, is still controversial. A recent meta-analysis of cohort studies found that moderate coffee intake was associated with lower cardiovascular disease risk,8Ā but a previous meta-analysis did not find such association.9Ā There are also conflicting data on the associations between coffee and tea intake with coronary artery calcification, a measure of subclinical atherosclerosis.10,Ā 11,Ā 12
Research in this field is challenging owing to potential confounding of coffee and tea consumption with demographic and other nutritional variables. Associations with clinical outcomes may be due to coffee or tea intake itself, to what is added or eaten with these beverages, or related to socioeconomic factors. Therefore, in assessing the cardiovascular implications of coffee and tea intake, it is critical to study a diverse population with sociodemographic and clinical characteristics. Moreover, simultaneously assessing the underlying disease (subclinical atherosclerosis) as well as the cardiovascular events themselves in a single large, prospective, cohort study may support a causal association. In the Multi-Ethnic Study of Atherosclerosis (MESA), we sought to investigate the association between coffee and tea intake with coronary artery calcium prevalence, progression, and cardiovascular events.
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-P. Elliott Miller, MD, Di Zhao, PhD, Alexis C. Frazier-Wood, PhD, Erin D. Michos, MD, MHS, Michelle Averill, PhD, Veit Sandfort, MD, Gregory L. Burke, MD, MSc, Joseph F. Polak, MD, MPH, Joao A.C. Lima, MD, Wendy S. Post, MD, MHS, Roger S. Blumenthal, MD, Eliseo Guallar, MD, Seth S. Martin, MD, MHS
This article originally appeared in theĀ FebruaryĀ 2017Ā issueĀ ofĀ The American Journal of Medicine.
