THE EFFECTS OF CAFFEINE ON BLOOD-PRESSURE AND HEART-RATE - A REVIEW

Concerns have been raised frequently about caffeine's potential for in creasing blood pressure (BP) and posing a risk for cardiovascular dise ase. This review surveys research concerning the effects of caffeine o n BP and heart rate (HR). Tolerance to caffeine, family history of hyp ertension, borderline hypertension; and hypertension are also examined as potential moderators. Results from epidemiological studies are inc onsistent. Experimental laboratory studies have generally found that c af feine produces acute rises in systolic and diastolic BP that are ad ditive to any stress-induced increases. Synergistic effects which migh t pose a more serious risk are rarely found. Heart rate data are less consistent, possibly due to the different ways HR is measured. Toleran ce to the cardiovascular effects of caffeine has reliably been reporte d; however, overnight abstinence may be sufficient to negate tolerance effects to most levels of caffeine ingestion in typical caffeine user s. Though caffeine drinkers may exhibit acute increases in BP, the lon g-term effects appear to be minimal. However, persons at risk for hype rtension may be more vulnerable to the BP effects of caffeine.