FRIDAY, Oct. 1, 2010 (HealthDay News) -- In yet another study, a moderate intake of alcohol has been shown to be healthy for the heart.
The current research found that when women consumed between one-half to one drink a day, their risk of sudden cardiac death dropped by 36 percent.
However, when women doubled their intake and had more than two drinks per day, they upped their risk of sudden cardiac death by about 15 percent.
"Numerous studies have found a protective association between alcohol intake and coronary heart disease, stroke and congestive heart failure, but little research has been done on alcohol and sudden cardiac death," explained study author Stephanie Chiuve, an instructor in medicine at Brigham and Women's Hospital in Boston.
"In this study, we wanted to look at the association of moderate alcohol intake and the risk of sudden cardiac death in women. We found a U-shaped association between alcohol and sudden cardiac death," said Chiuve, which means that too little or too much alcohol intake was associated with a higher risk of sudden cardiac death than moderate intake of alcohol.
"For women who choose to drink alcohol, they should have about one drink a day. That's where we saw the greatest benefit," she said.
Results of the study are published in the October issue of the journal Heart Rhythm.
Although the study wasn't designed to figure out exactly how alcohol might help prevent sudden cardiac death, Chiuve said that alcohol has a beneficial effect on cholesterol levels and helps reduce the amount of plaque that collects in the blood vessels. She said that it doesn't appear that any one particular type of alcohol is more beneficial than others, suggesting that it's the ethanol contained in alcoholic beverages that provides the health boost.
But, the news on alcohol isn't all good. Alcohol can also have what's known as pro-arrhythmic effects. That means alcohol can cause heart palpitations. The effect is so well-known that it's been dubbed "holiday heart syndrome."
Chiuve's study included 85,067 women from the Nurses' Health Study. None of the women had chronic disease when the study began, and all of the women answered questions about their alcohol intake every four years.
One drink is about 15 grams of alcohol, according to Chiuve. And, one drink translates to 12 ounces of beer, four ounces of wine or 1.5 ounces of liquor.
The researchers found that women who drank between 5 grams and 14.9 grams of alcohol daily had the lowest risk of sudden cardiac death. Those who were former drinkers had a 21 percent reduced risk of sudden cardiac death compared to teetotalers, according to the study.
Women who drank 0.1 to 4.9 grams of alcohol daily had a 23 percent reduced risk of sudden cardiac death compared to lifetime abstainers, while those who has 5 to 14.9 grams of alcohol each day reduced their sudden cardiac death risk by 36 percent. Women who had 15 to 29.9 grams of daily alcohol had a 32 percent reduced risk of sudden cardiac death.
But, once the amount of daily alcohol got above 30 grams -- two drinks a day -- the risk of sudden cardiac death increased by 15 percent over the teetotaling group.
Dr. Michael Davidson, director of preventive cardiology at the University of Chicago Medical Center, wasn't surprised by the findings. "There's always been this issue of a U-shaped curve for alcohol's effects. It's beneficial to a point, but once you go over a certain amount of alcohol, the risk of death goes up," he said.
He noted that when he has patients with heart palpitations, he suggests that they cut back on their alcohol intake to see if that helps.
But, he added, "everybody's different, and everyone's tolerance of alcohol is different, so if you feel fluttering in your heart and you've only had one drink, it may be the alcohol and that may be too much for you."
To learn more about the connection between alcohol and the heart, visit the American Heart Association.