Over the years, a lot of research studies have been conducted to assess the effect of caffeine on heart health. This is a highly relevant topic considering that
- Coffee is one of the most popular drinks in the world, hot or cold.
- Energy drink consumption which contains high amounts of caffeine has become a very popular soft drink among the young and even used as performance enhancer.
Many of those studies report inconclusive or contradictory results about the effect of caffeine on heart health.
A latest research study at Kaiser Permanente Division of Research, Oakland, CA explored the common belief that coffee causes palpitations, e.g. irregularity in the heartbeat when the heart literally “skips a beat.”
According to Dr Arthur Klatsky, who is leading the study:
“A lot of people think they have palpitations from coffee, and doctors commonly tell people not to drink it, but there are very few actual data, and the data that are available suggest no relationship. We went into this study thinking there would be no association, but to our surprise, there was actually an inverse relationship. It could be protective, although one observational study doesn’t prove anything yet.”
The researchers looked at 130,054 members of the Kaisers Permanente health plan and asked them to complete questionnaires on coffee drinking habits and other lifestyle factors.
The study results indicate that coffee consumption is associated with a lower risk for hospitalizations for arrhythmia (irregular heartbeat). In addition, the effect seems to be additive, e.g. the more coffee you drink, the lesser is the risk. As an example, those who drink more than 4 cups of coffee per day have an 18% less likelihood to have arrhythmia-induced hospitalization. The effect of caffeine consumption did not vary regardless of gender, ethnicity and smoking habits.
Is it really the caffeine?
Well, those who drank only decaf coffee did not have this protective effect so the evidence points to caffeine as the protective substance. However, the authors are quick to point out that coffee” is a complex substance and that it includes other ingredients that might be at work, including antioxidants, in reducing the risk of arrhythmias” which might have been drastically reduced during the decaffeinating process.
So what does caffeine do?
Dr. Klatsky and colleagues say the mechanisms behind the cardioprotective properties of caffeine are not fully understood but it may have something to do with caffeine competing with the compound adenosine in the brain. They speculate that the same competition might occur in the heart where adenosine is involved in the conduction and recovery of heart muscle cells after depolarization. However, more studies are needed to confirm these findings, including studies that will look into incidence of less sever arrhythmias that do not result in hospitalization.
However, the authors think it might be tricky to find subjects willing to cooperate with such studies.
Either you are a coffee drinker or you are not. I’m partial to lattes and mochas myself. Which one are you?