Objective: This review aims to determine whether, and to what extent, dietary caffeine may be a risk to cardiovascular health.
Methods: A critical review of the relevant experimental and epidemiologic literature was conducted, with particular reference to studies of caffeine and blood pressure (BP).
Results: There is extensive evidence that caffeine at dietary doses increases BP. However, concern that the drug may contribute to cardiovascular disease appears to have been dampened by (1) the belief that habitual use leads to the development of tolerance, and (2) confusion regarding relevant epidemiologic findings. When considered comprehensively, findings from experimental and epidemiologic studies converge to show that BP remains reactive to the pressor effects of caffeine in the diet. Overall, the impact of dietary caffeine on population BP levels is likely to be modest, probably in the region of 4/2 mm Hg. At these levels, however, population studies of BP indicate that caffeine use could account for premature deaths in the region of 14% for coronary heart disease and 20% for stroke.
Conclusions: Current evidence supports the conclusion that the BP-elevating effects of dietary caffeine may be contributing appreciably to population levels of cardiovascular mortality and morbidity. Accordingly, strategies for encouraging reduced dietary levels of caffeine deserve serious consideration.
National University of Ireland, Galway, Ireland.
Address correspondence and reprint requests to Prof. Jack E. James, Department of Psychology, National University of Ireland, Galway, Ireland. E-mail: email@example.com
Received for publication July 18, 2003; revision received September 30, 2003.
This work was supported by the European Commission Fifth Framework Program, Grant No. QLK1-CT-2000-00069.