Purpose: Aortic stiffness is an independent marker of cardiovascular risk. Caffeine, which is the strongest compound of coffee, has been associated with an acute, unfavorable effect on aortic elastic properties. Whether there is a differential chronic effect of coffee and caffeine on aortic stiffness has not been defined.

Methods: The chronic effect of coffee and caffeine were studied in 9 healthy volunteers. The study was carried out on four separate arms: a) triple espresso, b) decaffeinated triple espresso, c) 240mg of caffeine alone (amount contained in a triple espresso) and d) placebo. Each treatment period of two weeks was separated by wash-out periods of one week. Carotid-femoral pulse wave velocity (PWV) was measured as an index of aortic stiffness.

Results: The effect of daily caffeine and coffee intake on PWV is described as response of each variable, where response is defined as net caffeine or coffee minus placebo and decaffeinated coffee respectively values at each time point. PWV was significantly increased with caffeine compared to placebo (P<0.05, responses of 0.40 m/sec at 14 days). Furthermore PWV was significantly increased with coffee compared to decaffeinated coffee (P<0.05, responses of 0.43 m/s at 7 days and 0.57 m/s at 14 days). Both caffeine and coffee increased PWV, however, the effect of caffeine was more pronounced (P=0.07, response of 0.31 m/sec at 14 days).

Conclusions: Both coffee and caffeine increase PWV, however caffeine intake leads to a more potent chronic response. These findings indicate that substances other caffeine may partially counterbalance the chronic unfavourable effects of caffeine on the cardiovascular system.