HealthDay News — For adults with severe hypertension, high coffee consumption is associated with an increased risk for cardiovascular disease (CVD) mortality, according to a study published online December 21 in the Journal of the American Heart Association.
Masayuki Teramoto, MD, MPH, from the Osaka University Graduate School of Medicine in Japan, and colleagues examined the impact of coffee and green tea consumption on CVD mortality among 18,609 adults aged 40 to 79 years at baseline from the Japan Collaborative Cohort Study for Evaluation of Cancer Risk. Participants were classified into four categories of blood pressure (BP): optimal and normal, high-normal, grade 1 hypertension, and grade 2 to 3 hypertension.
The researchers documented 842 CVD deaths during a median of 18.9 years of follow-up. Among people with grade 2 to 3 hypertension, coffee consumption was associated with an increased risk for CVD mortality, with hazard ratios (95 percent confidence intervals) of 0.98 (0.67 to 1.43) for less than one cup/day; 0.74 (0.37 to 1.46) for one cup/day; and 2.05 (1.17 to 3.59) for 2 or more cups/day compared with nondrinkers. These associations were not seen among participants with optimal and normal BP, high-normal BP, or grade 1 hypertension. Across BP categories, no association was seen for green tea consumption with an increased risk for CVD.
“These findings may support the assertion that people with severe high blood pressure should avoid drinking excessive coffee,” a coauthor said in a statement. “Because people with severe hypertension are more susceptible to the effects of caffeine, caffeine’s harmful effects may outweigh its protective effects and may increase the risk of death.”