TEHRAN (Press Shia) – The effects of beverages such as coffee and tea are widely studied but still not clearly understood. Recently, the decision to have coffee carry cancer warning labels was met with mixed responses from experts and the general public.
Adding another key finding to the on-going debate on how caffeine affects our health, new research states that it may not be harmful to the heart. Patients who are diagnosed with atrial fibrillation/arrhythmias (a quivering or irregular heartbeat) are often advised to avoid caffeine.
Referring to this, the researchers have suggested that the stimulant may actually be linked to improved heart function. Furthermore, the form in which people consume their caffeine plays a significant role.
The review titled "Caffeine and Arrhythmias: Time to Grind the Data" was published in the April 2018 issue of Clinical Electrophysiology, a journal of the American College of Cardiology.
"There is a public perception, often based on anecdotal experience, that caffeine is a common acute trigger for heart rhythm problems," said lead author Dr. Peter Kistler, director of electrophysiology at Alfred Hospital and Baker Heart and Diabetes Institute in Australia. "Our extensive review of the medical literature suggests this is not the case."
To understand how caffeine intake affects arrhythmias, Dr. Kistler and co-authors examined a large number of population-based studies. A meta-analysis of 228,465 participants revealed that atrial fibrillation frequency decreased by 6% in regular coffee drinkers. A further analysis of 115,993 patients showed a 13% risk reduction.
Another study looked at 103 post-heart attack patients who received an average of 353 mg of caffeine each day. The results revealed an improved heart rate and no significant arrhythmias. Since atrial fibrillation can be caused by a chemical called adenosine, it is believed that caffeine plays a role in suppressing these effects. Both large population studies and randomized control trials suggested caffeine intake of up to 300 mg per day (or 3 cups of coffee a day) may be safe for arrhythmic patients.
"Caffeinated beverages such as coffee and tea may have long-term anti-arrhythmic properties mediated by antioxidant effects and antagonism of adenosine," Dr. Kistler said. "In numerous population-based studies, patients who regularly consume coffee and tea at moderate levels have a lower lifetime risk of developing heart rhythm problems and possibly improved survival."
However, the researchers recommended that patients with pre-existing heart conditions should avoid energy drinks as they may lead to abnormal rhythms and blood clots. Findings showed that roughly 75% of patients with such heart conditions who consumed two or more energy drinks experienced palpitations within 24 hours, Medical Daily reported.
The problem may lie with all the additional ingredients (sugar, ginseng, taurine etc.) in energy drinks, as noted in a 2017 study. The results of the study found that people experienced more concerning changes in heart activity after consuming energy drinks, compared to when they drank another beverage with similar levels of caffeine.