The tendency of caffeine to increase blood pressure has been well documented, but the mechanism of that effect has not been clear.

Now Irish researchers have shown that caffeine may actually increase the stiffness of arteries. Healthy participants in the study were observed after drinking either caffeinated or decaffeinated coffee. Researchers, measuring the properties of the arteries via reflection of arterial waves and aortic pressure waveforms, determined that the caffeine-drinkers experienced a significant effect on the tone and function of their arteries. No such effect was seen in those who drank decaffeinated coffee.

In another study, Greek researchers told the recent European Society of Cardiology Congress that they were able to measure the stiffening of arteries in healthy volunteers following a single cup of coffee. They suggested that elderly people and those with hypertension should be more cautious about caffeine consumption.

Related information: Lifestyle changes - Eating well | Risk factors - Controllable risks

Sources:

• Mahmud A, Feely J. Acute effect of caffeine on arterial stiffness and aortic pressure waveform. Hypertension, August 2001;38:227. (Abs.)
• European Society of Cardiology. Does a cup of coffee stiffen your arteries? Press release, Sept. 5, 2001.