Little data existed regarding the acute effects of energy drinks on myocardial function, Cameli said, before presenting the results of his small-scale study, due to be published in the European Heart Journal 2012.
Stimulates calcium release?
Despite concerns about the effects of caffeine and organic acid taurine on heart health, Cameli said that while caffeine raised blood pressure, taurine may stimulate the release of calcium (as an agent affecting heart contractions) from the so-called sarcoplasmic reticulum.
In layman’s terms, the sarcoplasmic reticulum is the storage and release area for calcium found in both cardiac muscle and skeletal muscle.
Cameli and colleagues Daniele Menci and Sergio Mondillo, dosed 35 healthy subjects (average age 25, 19 women, 10 smokers, 8 regular energy drink users, no drug users).
Dosage of 168ml/m2 with an energy drink containing both caffeine and taurine was linked to body surface area; fruit juice was consumed by the same group as a control.
Heart rate, blood pressure, left ventricular function and right ventricular function were assessed both at the start/baseline and one hour after consumption.
The research team found that overall average slight increases in heart rate and systolic blood pressure were not statistically significant, but a diastolic blood pressure increase of 6% was.
Left and right ventricular function both improved one hour after consuming energy drinks, and Cameli said that enhanced contractions within both showed that normal energy drink consumption had a positive inotropic effect on myocardial function.
Long-term health benefits?
(Any drug, substance or condition affecting the heart muscle’s contraction is described in terms of either a positive (strength increasing) or negative inotropic effect.)
“This [the positive effect]could be explained by the intropic effect of taurine that, as previously demonstrated, stimulates the release of calcium from the sarcoplasmic reticulum,” Cameli said.
Future studies were needed to assess if benefits persisted after long-term energy drink consumption, and the effects of consuming drinks during physical activity, he added.
“It will also be important to determine which of the effects are induced in patients with cardiac disease, to enhance our understanding of the potential benefits or risks of energy drink consumption,” Cameli said.
