In the past, those who have suffered from heart attacks have likely been advised by their doctors to limit their caffeine intake, or to avoid it altogether. However, a new study shows that those who have had a heart attack or suffer from heart failure can safely drink up to five cups of coffee per day without any added risk.
The study, which was conducted in Brazil at the Federal University of Rio Grande do Sul, has found that there is no link between caffeine intake and cardiac arrhythmias, or the irregular beating of the heart. Anything that can induce an arrhythmia is to be avoided by those who have heart problems, as this can induce damage to heart tissue, and in some cases, sudden death.
The study, which was published in JAMA Internal Medicine, was a small randomized trial.
51 participants took part in the research. 25 of them were given decaffeinated coffee with caffeine powder and 26 received decaffeinated coffee with a placebo.
The participants drank one cup of coffee per hour for five hours. At the end of the five hours, the group who drank the caffeinated coffee had ingested 500mg of caffeine, which is roughly the same as five cups of instant coffee or six cans of Red Bull.
One hour after the last cup of coffee, they took a treadmill test to see if physical activity induced any type of arrhythmia. No evidence was found, even with increased physical activity, that the caffeine causes any type of abnormal heart beat.
Although the sample group was small, researchers believe that this disproves the recommendation that those with heart problems avoid caffeine.
Professor Dr. Luis Rohde, who led the study, also stated that around half of those who participated in the study were regular coffee drinkers. He does acknowledge that this could skew test results, in that they may have become tolerant to the effects of the caffeine and therefore arrhythmias were not as pronounced. However, he does state that this is not incredibly likely.
Rohde says of his study:
“To date, there is no solid evidence to support the common recommendation to limit moderate caffeine consumption in patients at risk for arrhythmias.”
However, some institutions and experts remain skeptical.
A spokesperson at the Australian Heart Foundation stated that this study only proved that some people with heart problems would be able to drink caffeine without an issue, but it does not translate to everyone.
Because the study was so small, many charities and foundations with an interest in heart health say they won’t be changing their guidelines just yet.