One study stands out supporting the claim that coffee is good for high blood pressure.
The study suggested that drinking coffee makes the blood vessels more elastic, which may help counteract high blood pressure.
In the study, researchers from the University of Athens concluded that participants who drank one-two cups per day had 25% greater elasticity in their blood vessels compared to those who do not drink coffee. [“Caffeine: How does it affect blood pressure?”, mayoclinic.com]
More Is not the Answer
In the study, those who drank only a few cups had up to five times greater elasticity in their blood vessels than those that had three or more cups. [“Caffeine: How does it affect blood pressure?”, mayoclinic.com]
One Study Is not Sufficient Evidence
The American Heart Association does not substantiate these claims and warns that the study is only preliminary.
All the Data
In a meta-analysis of available study data, researchers concluded that though consumption of caffeinated beverages appears to increase blood pressure during the first hour lasting up to three hours, most studies conclude that there are no long-term elevated blood pressure effects. [Mesas, 1113]
Armed with this information, it is important that you do not drink caffeinated beverages for up to three hours before having your blood pressure evaluated.
Mesas, A.E., and et al. “The effect of coffee on blood pressure and cardiovascular disease in hypertensive individuals: a systematic review and meta-analysis..” American Journal of Clinical Nutrition 94.4 (2011): 1113-1126. Print
“Coffee May Combat High Blood Pressure.” WebMD – Better information. Better health.. N.p., n.d. Web. 16 Apr. 2012. <http://www.webmd.com/hypertension-high-blood-pressure/news/20100901/coffee-may-combat-high-blood-pressure>.
“Caffeine: How does it affect blood pressure? – MayoClinic.com.” Mayo Clinic. N.p., n.d. Web. 16 Apr. 2012. <http://www.mayoclinic.com/health/blood-pressure/AN00792>.
“Will Drinking a Lot of Coffee Send Your Blood Pressure Up?.” NIH Heart, Lung and Blood Institute. N.p., n.d. Web. 16 Apr. 2012. <http://www.nhlbi.nih.gov/hbp/prevent/factors/coffee.htm>