Effect of coffee on endothelial function in healthy subjects: the role of caffeine

Coffee is one of the most widely used pharmacologically active beverages. The present study was designed to evaluate the acute effect of coffee ingestion on endothelial function in healthy individuals, and the potential role of caffeine. We studied 17 healthy young adults (28.9 +/- 3.0 years old; nine men), who were regular non-heavy coffee drinkers. The endothelial performance was estimated by endothelium-dependent FMD (flow-mediated dilatation) of the brachial artery before and 30, 60, 90 and 120 min after ingestion of a cup of caffeinated coffee (80 mg of caffeine) or the corresponding decaffeinated beverage (< 2 mg of caffeine) in two separate sessions, following a randomized single-blind cross-over design. There was no difference in baseline FMD values between the two sessions [7.78 compared with 7.07% after caffeinated and decaffeinated coffee respectively; P = NS (not significant)]. Caffeinated coffee led to a decline of FMD (7.78, 2.86, 2.12, 4.44 and 4.57 % at baseline, 30, 60, 90 and 120 min respectively; P < 0.001). This adverse effect was focused at 30 (P = 0.004) and 60 min (P < 0.001). No significant effect on FMD was found with the decaffeinated coffee session (7.07, 6.24, 5.21, 7.41 and 5.20 %; P = NS). The composite effect of the type of coffee consumed over time on FMD was significantly different (P = 0.021). In conclusion, coffee exerts an acute unfavourable effect on the endothelial function in healthy adults, lasting for at least I h after intake. This effect might be attributed to caffeine, given that decaffeinated coffee was not associated with any change in the endothelial performance

Arterial compliance may be reduced by ingestion of red wine

The aim of this study was to assess the effect of alcohol on blood pressure and arterial compliance over 24 h in a group of volunteers, comparing the same group of subjects on two consecutive but separate days, one with alcohol intake (alcohol day) and one free of alcohol (control day). We studied 18 healthy subjects (mean age 34.2 years, range 25-53). The subjects received the two days in random order. On the alcohol day, the subjects were asked to drink two glasses of red wine (12% ethanol) between 1830 hours and 0430 hours. Measurements of heart rate, blood pressure and QKD interval (Q wave to Korotkoff (K) sound, diastolic phase (D) using Diasys Integra (Novacor, France)) were recorded (usually 1500 hours to 1500 hours). Three 'ingestion' periods were defined, from 1500 hours to 1830 hours ('before'), 1900 hours to 0430 hours ('during') and from 0430 hours to the following afternoon ('after') on both the alcohol day and on the control day. Red wine increased heart rate during alcohol ingestion and reduced arterial compliance after ingestion. The significant effect of interaction between day and ingestion period on heart rate, diastolic blood pressure and QKD were found, suggesting that the differences in response among the ingestion periods depended on whether alcohol has been consumed that day. For the first time our study indicates the effect of alcohol on 24 h arterial stiffness in a healthy group of volunteers.Journal of Human Hypertension advance online publication, 19 March 2015; doi:10.1038/jhh.2015.19