These individual differences make it hard to make broad recommendations on drinking alcohol. Each person must know what is a moderate amount for himself or herself. The US Department of Health and Human Services defines moderate drinking as not more than 2 drinks per day for an average healthy man and not more than 1 drink per day for an average healthy woman. In small doses, alcohol may be beneficial for some people. In moderation, wine may help protect against heart disease , especially coronary artery disease .
Nobody knows exactly why.
There are many theories. Some studies have investigated the ability of alcohol to raise HDL cholesterol . HDL cholesterol is the so-called good cholesterol. Other studies have looked at the blood-thinning properties of alcohol. Other studies have inspected phytochemicals.