We've all heard that an occasional drink can help your heart and your health.
But where do you draw the line on that glass of wine, or beer with friends?
There's never been a number, until now.
Swedish researchers followed more than 5,000 sets of twins over 40 years, surveying their drinking habits.
In the middle-age twins who drank more than 2 alcoholic beverages a day had a 34% higher risk of stroke than those who drank less than half a daily drink.
And those who drank heavily were far more likely to have a stroke a full 5 years ahead of light drinkers.
In heavy drinkers, the increase in stroke risk from alcohol is just as bad, and sometimes worse, than it is from diabetes and high blood pressure.
The American Heart Association says if you don't want to raise your risk of stroke, stick to 2 drinks a day for men, and just one for women.
Don't forget, a "standard" drink is defined as 5 ounces of wine or 12 ounces of regular beer.