Acute Cardiovascular Effects of Turkish Coffee Assessed by VO Test: A Randomized Crossover Trial.

Background: Turkish coffee (TC), a traditional unfiltered coffee preparation method, contains unique bioactive compounds due to its specific brewing process. While TC's cultural significance is well-documented, its acute physiological and psychological effects remain understudied.

Objectives: This randomized, controlled crossover trial investigated the acute effects of a standardized TC dose (3 mg caffeine/kg body weight) on metabolic and psychological parameters in healthy female university students (n = 52, age: 20.25 ± 1.20 years).

Methods: TC was prepared with a 1:1 ratio of medium and dark roasted Arabica beans. The chemical analysis showed the caffeine content to be 2.8 ± 0.3 mg/mL and the chlorogenic acid content to be 1.9 ± 0.2 mg/ml. Participants were randomized to receive either TC or water control, with a washout period of 8 weeks between treatments. Cardiovascular parameters, metabolic markers, and validated visual analog scales (VAS) were assessed at baseline, 60-, 90-, and 120-min post-consumption.

Results: Heart rate showed significant time-dependent reductions in both groups (control: < 0.05; TC: -value < 0.01 at 60, 90, and 120 min vs. baseline). Heart rate dropped significantly in the Turkish coffee group, from 78.0 ± 10.2 bpm at baseline to 71.5 ± 9.5 bpm after 90 min (-value = 0.002). Sleep scores also declined, from 4.38 ± 2.91 at baseline to 1.88 ± 1.45 after 120 min ( < 0.05), indicating a stimulating effect of caffeine. TC consumption significantly affected appetite sensations ( < 0.05) and sleep scores (F = 3.174, -value = 0.029), with the TC group showing progressive reductions in sleep scores from baseline (4.38 ± 2.91) to 60 min (2.58 ± 2.04), and further decreases at 90 and 120 min.

Conclusions: These findings suggest that TC exerts significant acute effects on cardiovascular function and psychophysiological parameters in healthy young females, potentially due to its unique phytochemical profile and preparation method.