Coffee Consumption and Mortality From All Causes, Cardiovascular Disease, and Cancer: A Dose-Response Meta-analysis

Alessio Crippa; Andrea Discacciati; Susanna C. Larsson; Alicja Wolk; Nicola Orsini

Disclosures

Am J Epidemiol. 2014;180(8):763-775. 

In This Article

Abstract and Introduction

Abstract

Several studies have analyzed the relationship between coffee consumption and mortality, but the shape of the association remains unclear. We conducted a dose-response meta-analysis of prospective studies to examine the dose-response associations between coffee consumption and mortality from all causes, cardiovascular disease (CVD), and all cancers. Pertinent studies, published between 1966 and 2013, were identified by searching PubMed and by reviewing the reference lists of the selected articles. Prospective studies in which investigators reported relative risks of mortality from all causes, CVD, and all cancers for 3 or more categories of coffee consumption were eligible. Results from individual studies were pooled using a random-effects model. Twenty-one prospective studies, with 121,915 deaths and 997,464 participants, met the inclusion criteria. There was strong evidence of nonlinear associations between coffee consumption and mortality for all causes and CVD (P for nonlinearity < 0.001). The largest risk reductions were observed for 4 cups/day for all-cause mortality (16%, 95% confidence interval: 13, 18) and 3 cups/day for CVD mortality (21%, 95% confidence interval: 16, 26). Coffee consumption was not associated with cancer mortality. Findings from this meta-analysis indicate that coffee consumption is inversely associated with all-cause and CVD mortality.

Introduction

Coffee is one of the most commonly consumed beverages around the world. Because of its popularity, even small health effects could have important public health consequences. Coffee has been considered potentially unhealthy, since caffeine intake has been positively associated with blood pressure,[1] serum lipid concentration,[2] cholesterol levels,[3] and insulin resistance.[4] Prospective studies, however, have generally not supported adverse health effects associated with coffee consumption. Besides caffeine, coffee contains several bioactive compounds with potentially beneficial properties, such as insulin-sensitizing[5] and antiinflammatory[6] effects.

Several quantitative reviews have indicated that coffee consumption may decrease the incidence of common chronic diseases, including type 2 diabetes,[7] heart disease,[8] and specific types of cancers.[9] Only 2 meta-analyses have examined the association between coffee and mortality, pooling relative risks for the highest category of coffee consumption versus the lowest.[10,11] A weak inverse association was found for all-cause mortality,[10,11] while an unclear association was found for cardiovascular disease (CVD) and no association was found for cancer mortality.[10] A dose-response analysis uses all of the exposure-disease information, including intermediate categories, and is therefore more efficient than the highest-versus-lowest approach. In addition, it is less sensitive to the variability of exposure categories and more flexible in modeling the relationship under investigation. In particular, it provides a detailed description of the risk of death throughout the observed range of exposure, thus allowing identification of those values associated with the highest or lowest risk. Because the shapes of the associations remain uncertain, we conducted a dose-response meta-analysis of prospective studies on coffee and mortality to examine the exposure-disease associations between coffee consumption and mortality from all causes, CVD, and cancer.

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