Does coffee affect blood pressure?

Caffeine can temporarily raise blood pressure (BP), but the long-term effects of regular coffee drinking are less clear. In a study from Italy, published in the Journal of Hypertension, researchers looked at BP in 1,400 participants based on their daily coffee consumption: none, moderate (1-2 cups), or heavy (3 or more cups). They measured BP in the office, at home, and with a 24-hour monitor at the start of the study and after 10 years. Most participants kept the same coffee habits throughout the study.

The three groups had some differences at the beginning: heavy coffee drinkers were generally younger, more likely to smoke, and less likely to be on blood pressure medications. After adjusting for these differences, the only notable finding was that heavy coffee drinkers had a slightly lower average office systolic BP compared to moderate and non-drinkers, both at the beginning and after 10 years. At either time point, there were no differences in BP readings taken at home or with the 24-hour monitor between the groups. Additionally, there were no differences in BP variability over 24 hours or in the development of new hypertension among the groups.

These results suggest that regular coffee consumption does not lead to clinically meaningful differences in BP or the incidence of hypertension. Patients can be reassured that a daily coffee habit is not likely to affect their BP.