The positive effects of alcohol, associated with moderate drinking only, include:
- raising levels of the "good" cholesterol, HDL
- preventing platelets from forming blood clots
- reducing the buildup of plaque in the circulatory system
The following negative effects of alcohol on the heart are usually associated with heavy drinking:
- high blood pressure
- heart failure
- weight gain, leading to high blood pressure
- enlarged heart
According to the American Heart Association, although caffeine has many effects on the human body, at present no links have been confirmed between caffeine intake and heart disease.
In addition, studies have not found a link between caffeine and arrhythmia. However, reports indicate that drinking more than 5 cups of coffee each day can raise blood pressure.
The American Heart Association advise individuals with A-fib to avoid excessive amounts of alcohol and caffeine.
However, a report published in the Journal of the American College of Cardiology found that even moderate use of alcohol increased the risk of A-fib. The risk rose by around 8 percent with each additional drink taken per day.
A third study found that two drinks each day for women did not increase the risk of A-fib, but three or more did. Another study found that the risk did not increase for men until they had more than five drinks per day.
There is some concern among experts regarding energy drinks. This is due to the high level of caffeine they contain and observed increases in the heart's contraction rate. Healthy young adults could tolerate this increase, but it could be a problem for children and those with pre-existing heart conditions.