By: Thomas Pickering, MD, DPhil, FRCP, Director of Integrative and Behavioral Cardiology Program
of the Cardiovascular Institute at Mount Sinai School of Medicine, New York.
Caffeine is a powerful stimulant of the cardiovascular system, and the immediate effects of drinking a cup of coffee are an increase of blood pressure and heart rate, which may last for 15 minutes or so. It has also been suggested that regular consumption of coffee may produce a more sustained elevation of blood pressure, which might be of concern to people who have hypertension. A recent review of the evidence on this point examined all the studies in which blood pressure was measured in coffee drinkers during periods of two weeks or longer when they were either drinking coffee (on average five cups per day) or abstaining. All the subjects in these studies had normal blood pressures. The effect of drinking this amount of coffee was to raise blood pressure by 2-3 mmHg of systolic pressure, and 1 mmHg of diastolic. It was also concluded that
coffee had a bigger effect on blood pressure in younger than in older people.
If you have high blood pressure and drink a lot of coffee, the results of this analysis suggest that if you stop drinking coffee (or possibly switch to decaffeinated) you may experience a slight fall of your blood pressure, but donít expect a dramatic change. It is worth noting that people who drink a lot of coffee do not appear to be at increased risk of stroke or a heart attack.
Where it was published
S H Jee and colleagues. The effect of chronic coffee drinking on blood pressure. meta-analysis of controlled clinical trials. Hypertension 199;33:647.