ATLANTA, Georgia (CNN) -- We've heard for nearly a decade about the benefits of alcohol -- red wine in particular. It's good for your heart and may have other positive effects. In moderation, we thought, it's not only OK, but actually good for us.
A 2000 study found that red wine drinkers had half the risk of dying from heart disease as nondrinkers.
But now there's a different risk to consider: New research appears to show a link between alcohol and breast cancer in women.
So what's a girl to do about her nightly glass of wine?
The short answer is, you have to judge for yourself, based on your health and your family medical history. Keep in mind that heart disease is the leading killer of women; in fact, women are six times as likely to die of heart disease as breast cancer.
According to the new research, drinking just one to two drinks a day increases a woman's risk of breast cancer by 10 percent. Make that three or more drinks a day, and the risk triples to 30 percent.
Researchers at Kaiser Permanente analyzed data on the drinking habits of 70,033 women of various races and backgrounds. They were trying to determine whether the type of alcohol or just the amount a woman drinks impacts her breast cancer risk. Lead researcher, Dr. Yan Li, says they discovered "it makes no difference if a woman drinks wine, beer or liquor -- it's the alcohol itself and the quantity consumed" that is critical. In fact, drinking three or more drinks a day may translate into an extra 5 percent of all women developing breast cancer as a result of heavy drinking.
Alcohol, not just red wine, has been shown to help your heart in several ways: by raising your HDL or "good" cholesterol, lowering blood pressure and preventing the formation of blood clots. Watch to learn more about the new research »
Red wine gained its "heart healthy" reputation after a Danish study in 2000 found red wine drinkers had half the risk of dying from heart disease as nondrinkers. However, other studies on the subject have been mixed. Researchers suspect that if red wine holds a benefit it may come from flavonoids and antioxidants, which help protect the lining of blood vessels in the heart. Resveratrol is one such antioxidant that's gotten a lot of attention because some researchers believe it may reduce LDL, or "bad" cholesterol, and prevent blood clots.
While this is compelling, the American Heart Association says more research is needed. Until then they do not recommend drinking wine or any other alcohol just for these benefits.
As for why heavy alcohol use seems to be raising a woman's risk for breast cancer -- that's a mystery. "We would love to know why," Dr. Li says, but she and her colleagues believe there is evidence that alcohol could alter the pathway of female hormones and produce more hormone sensitive breast cancer. But that needs further study.
So do the heart-health benefits outweigh the newly shown risk of breast cancer? Researcher Dr. Li says, "Each woman has to analyze her own risk factors to determine what alcohol will do to them."
In the meantime, if you still want your glass of red wine, the American Cancer Society recommends limiting alcohol consumption to one drink a day or less.
Spokeswoman Heather Spencer Feigelson says the bottom line is, the "risk of drinking one glass of red wine a day (is) very low; it's an individual choice." Cancer experts tell CNN every woman needs to balance her own risk of heart disease and breast cancer and decide for herself. E-mail to a friend
Karen Denice is a producer with CNN Medical News.
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