Coffee is one of the most popular beverages. Its stimulatory effects comes from the natural alkaloid- caffeine. Caffeine is the antagonist of the adenosine receptors A1 and A2. Caffeine acts chronotropic positive and increases heart action; inotropic positive and increases cardiac contraction; tronotropic positive and increases hearts muscular ton, brain's vascular stenosis, vasodilatation of coronal vessels, renal vessels, muscular vessels and skin vessels. The aim of the study was determination of coffee effect on blood pressure in healthy subjects.
Material and methods: 17 healthy subjects (age 22-44 years; median 22 years) was included. There were two experiments. Experiment 1: examined persons drank instant coffee with or without caffeine. Experiment 2: examined persons drank natural coffee with or without caffeine. The blood pressure and pulse were examined before coffee drinking and 15 and 30 minutes after (in experiment 1) and only 30 minutes after (in experiment 2).
Results: The blood pressure was increased on 10 mmHg or more in 9-40% of examined subjects in all groups, but there were no significant difference between groups. The pulse increased (10 or more per minute) was observed only in one person and decrease was observed in three who drank natural coffee with caffeine.
Conclusions: In healthy subjects the blood pressure does not increased significantly after caffeine consumption. The consumption of caffeine in large doses may be harmful to some hypertensive or hypertension-prone subjects.