An ice cold beer can be refreshing, and a glass of wine can be relaxing, but is alcohol safe for your heart? Alcohol consumption in moderation has a reputation for being heart-healthy, and a new study of nearly 2 million people seems to confirm that, but only to a certain degree.
They also looked at other information in the records, including how much alcohol the subjects reported drinking. Based on their drinking habits, each participant was placed in one of five groups: nondrinkers, former drinkers, occasional drinkers, moderate drinkers, and heavy drinkers.
Moderate alcohol intake is considered up to 1 drink a day for women, and up to 2 drinks a day for men. 
One drink contains 0.6 fluid ounces of alcohol and is defined as:
- 12 fl. oz. of regular beer (5% alcohol)
- 4-5 fl. oz. of wine (12% alcohol)
- 1.5 fl. oz. of 80-proof distilled spirits (40% alcohol)
- 1 fl. oz. of 100-proof distilled spirits (50% alcohol)
According to the study, there were no heart conditions for which the nondrinkers had the lowest risk. In other words, they found that drinking was not necessarily bad for the heart. 
Compared with those who never drank, moderate drinkers were actually less likely to be diagnosed with chest pain, heart failure, stroke, peripheral artery disease, and several other conditions. No statistically significant differences were found between the groups for other conditions.
The heavy drinkers, on the other hand, were found to be more likely to be diagnosed with conditions like heart failure, cardiac arrest, peripheral artery disease, and stroke compared with moderate drinkers, which supports earlier findings that heavy drinking is not good for heart health.
Yet the heavy drinkers were less likely to be diagnosed with a heart attack than moderate drinkers. The researchers wrote that this doesn’t mean that heavy drinkers are not at risk for having a heart attack. It simply means a heart attack is less likely to be the first heart problem heavy drinkers have.
As for former drinkers, the researchers found that they were more likely than current drinkers to be diagnosed with certain heart conditions, including chest pain, heart attack, cardiac arrest, and aortic aneurysm. This doesn’t mean that people shouldn’t quit drinking. The finding suggests that some people quit in part because they are developing health problems from drinking.
Additionally, alcohol does not appear to protect against four less common heart problems: certain types of milder strokes caused by brief periods of blocked blood flow to the brain, and cases of bleeding in the brain. 
Overall, the study suggests that moderate drinking is associated with a lower risk for several heart conditions.
But if you don’t drink, or you drink rarely, the researchers advise against becoming a moderate drinker to protect your heart. It’s much safer to quit smoking, eat right, and get enough exercise.
The science behind the health effects of drinking have always been murky. Past studies showed that having two alcoholic drinks a day increased the risk for atrial fibrillation, or irregular heartbeat, by 17%. This condition can lead to stroke and heart failure. And while moderate wine consumption has been linked with a lower risk for breast cancer, recent research suggests that the risk increases as alcohol intake increases.
So if you don’t drink, don’t start for the sake of your health. And if you drink a lot, you should consider cutting back for your health’s sake.
 Live Science