FRIDAY, Jan. 30, 2015 (HealthDay News) — Red Bull consumption combined with mental stress correlates with increased blood pressure (BP) and heart rate, according to a study published in the Jan. 15 issue of The American Journal of Cardiology.
Erik Konrad Grasser, M.D., Ph.D., from the University of Fribourg in Switzerland, and colleagues examined the consequences of Red Bull ingestion in combination with mental stress. Twenty healthy participants ingested 355 ml Red Bull or water and underwent a mental arithmetic test for five minutes 80 minutes later.
The researchers found that water had no significant effects, but Red Bull increased systolic and diastolic BP (+7 mm Hg and +4 mm Hg, respectively) and heart rate (+7 beats/min). There was a greater decrease in cerebral blood flow velocity with Red Bull versus water ingestion (−9 versus −3 cm/s; P < 0.005). There were further increases in systolic and diastolic BP (+3 mm Hg; P < 0.05) and heart rate (+13 beats/min; P < 0.005) with additional mental stress after ingestion of Red Bull; similar increases were also seen after ingestion of water. The combination of Red Bull and mental stress increased systolic and diastolic BP (about +10 mm Hg and +7 mm Hg, respectively) and heart rate (+20 beats/min), and decreased cerebral blood flow velocity (−7 cm/s).
“The combination of Red Bull and mental stress impose a cumulative cardiovascular load and reduces cerebral blood flow even under a mental challenge,” the authors write.