Despite previous controversy on the subject, most researchers now conclude that regular coffee and caffeine use has little or no effect on blood pressure. Studies indicate that while first-time caffeine use may produce immediate, minimal changes in blood pressure, these changes are transient. No changes in blood pressure appear to occur in regular users of caffeine. A 1991 study reached the same conclusion and indicated that restricting caffeine did not reduce blood pressure in people with mild hypertension. A number of studies that have looked at people with normal blood pressure have concluded that caffeine does not contribute to hypertension.
Heart arrhythmias are irregularities of the heartbeat.
A growing body of research indicates that the heartbeat irregularities are not affected by coffee and caffeine consumption for the vast majority of individuals, both healthy individuals and those with heart disease. In fact, some studies have found that consuming caffeine has a positive effect on exercise performance, increasing both energy and endurance. Likewise, more recent research in 1999 demonstrated that people with sound diets showed no effect on their plasma homocysteine levels from all forms of coffee consumption. This information has been reviewed by Harvey Wolinsky, M.D., a cardiologist in New York.