The Examination of the Influence of Caffeinated Coffee Consumption on the Concentrations of Serum Prolactin and Selected Parameters of the Oxidative-Antioxidant Balance in Young Adults: A Preliminary Report

Abstract

We verified whether caffeinated coffee consumption influenced the concentrations of prolactin (PRL) and oxidative stress parameters: total antioxidant status (TAS), ferric reducing antioxidant power (FRAP), total oxidant status (TOS), oxidative stress index (OSI), advanced oxidation protein products (AOPP), uric acid (UA), total bilirubin (T-Bil), albumin (ALB), iron (Fe), calcium (Ca), magnesium (Mg), and inflammatory marker C-reactive protein (CRP)-in blood sera obtained at 15, 60, and 120 minutes after caffeinated coffee intake, in relation to the fasting point. The study participants were 33 young, healthy, nonsmoking volunteers (15 men, 18 women) aged 19-29 years. PRL concentrations significantly decreased (p < 0.05) after consumption, except at time point 15' in men (p > 0.05). In women, FRAP levels significantly increased over time, and significant changes were also observed for UA at 120' and ALB at 15'. In men, significant changes were found for levels of AOPP at 15', T-Bil and ALB at 15', iron at 60' and 120', and calcium at 120'. There were no significant differences in the levels of other examined parameters between the defined time points. In conclusion, the substances contained in caffeinated coffee decrease the level of prolactin and may also have an impact on selected parameters of oxidative stress, which could be the basis of future research focused on the identification of new therapeutic targets.

Figure 1

The main ingredients of coffee with an antioxidant effect.

Figure 2

Schematic representation of experimental procedures. PRL: prolactin; OS: oxidative stress.

Figure 3

The concentration values of prolactin for women and men. SD: standard deviation; p value was calculated versus time point 0', and a two-tailed p value of less than 0.05 was considered significant. 0', 15', 60', and 120': time points of measurements.

Figure 4

Scheme of interactions between oxidative stress development and levels of serum oxidative stress parameters in relation to time points of measurement after caffeinated coffee consumption. ALB: albumin; Ca: calcium; FRAP: ferric reducing antioxidant power; PRL: prolactin; T-Bil: total bilirubin; UA: uric acid. Versus time point 0': NS: not significant; ↑: significantly increased; ↓: significantly decreased.