Longitudinal Changes in The Association Between Coffee Intake and Ischaemic Heart Disease From 1990 to 2018: An International Ecological Study

In previous observational studies, the association between coffee consumption and the risk of cardiovascular disease has reversed from positive to negative over time. This long-term international ecological study examined whether the association between coffee intake and the mortality and incidence rates of ischaemic heart disease (IHD) changed between 1990 and 2018. We obtained data on coffee intake per capita (cups per day) and IHD mortality and incidence per 100,000 population, and socioeconomic and lifestyle indicators for each country from various publicly available databases. We integrated and analysed data from 147 countries with populations of ≥1 million. We employed a linear mixed model analysis to assess the interaction among coffee intake, IHD mortality and incidence rates by year. The random effects in the mixed model were the intercept and slope by year for each country. The mean global coffee intake increased (p<0.001), while IHD mortality (p<0.001) and incidence (p=0.073) decreased. In all models, the interaction between coffee intake and year showed a significant inverse association for IHD mortality and incidence rates (p<0.001 for all). The country-level association between coffee intake and IHD mortality and incidence rates was stronger in the negative direction between 1990 and 2018.