Feb. 25, 2009 -- Even moderate alcohol consumption of more than two drinks a week may raise the risk of cancer, according to a new study, despite past research suggesting that light drinking can benefit your health. So what's the truth?
The latest piece of evidence on the risks of drinking alcohol comes from researchers at Oxford University who studied more than 1.2 million women in the United Kingdom. They found that drinking alcohol may account for about 13 percent of all breast , liver, rectal and upper digestive tract cancers in women.
More shocking, even small amounts of alcohol seemed to increase the cancer risk. When compared with women who drank two or fewer alcoholic beverages per week, those drinking up to six alcoholic beverages had a 2 percent greater risk for cancer in general; those consuming between seven and 14 drinks per week had a 5 percent increased risk for cancer; and those consuming 15 or more per week had a 15 percent increased risk for cancer.
Using these findings, Dr. Michael Lauer, director of the Division of Prevention and Population Sciences at the National Heart, Lung, and Blood Institute in Bethesda, Md., wrote in the study's editorial that "there is no level of alcohol consumption that can be considered safe."
But with all we've heard in the past about the supposed health benefits of alcohol, can this really be the case?
Most experts say no.
"The editorialists … seem to be rather extreme in their views," said Dr. Charles Poole, associate professor of epidemiology in the Gillings School of Global Public Health at the University of North Carolina. "I have seldom seen such a one-sided dismissal of the hypothesis that moderate alcohol use may have cardiovascular benefits."
Alcohol for a Healthy Heart?
A study published in the British Medical Journal in May 2006 found that women who drank alcohol at least one day a week had about a 35 percent lower risk of coronary heart disease than women who drank alcohol less than once a week. For men, however, those who drank daily saw the largest reduction in risk when compared with nondrinkers -- about 41 percent.
The Fine Line Between Health and Illness
But it seems that the quantity of alcohol consumption plays a big role in whether you will see the risks or the benefits of a good buzz.
A meta-analysis (or overview of old studies) published in the Journal of the American Medical Association in 2003 found that light to moderate alcohol consumption could lower the risk for stroke, while heavy alcohol consumption raised the stroke risk.
Researchers found that those who consumed more than about 60 grams of alcohol per day, or about five drinks, had a 64 percent increase in overall stroke risk. But those who drank 12 grams of alcohol per day, or about one drink, experienced an 83 percent decrease in overall stroke risk.
Based on the body of available evidence on the benefits and risks of alcohol consumption, the American Cancer Society recommends that drinkers limit intake to one drink per day for women and two drinks per day for men.
Drink for Your Heart, or Stop Drinking for the Cancer Risk?
For some, this decision to start drinking for the heart benefits or stop drinking because of the increased cancer risk should be based on personal medical history.
"In light of the findings from [this study], women who are concerned about their cancer risk versus their risk of cardiovascular disease might want to discuss the potential risks and benefits of even low alcohol intake with their health care providers," said Susan Gapstur, associate director of Cancer Prevention and Control within the Robert H. Lurie Comprehensive Cancer Center at Northwestern University in Chicago.
And for those with a history of certain diseases such as breast cancer, experts said the heart-protective benefits of alcohol might not outweigh the overall increase in cancer risk caused by drinking.
"I think women at high breast cancer risk due to strong family history, or due to their own personal history, might be better off if they were to restrict alcohol intake to under one drink per day on average," said Dr. Tim Byers, associate dean of the Colorado School of Public Health at the University of Colorado at Denver.
The End Result: Alcohol's Effect on Life Expectancy
But for those whose personal history offers no added risk for alcohol consumption, taking a look at the overall life expectancy of alcohol drinkers might help to sway one's decision on whether the buzz is really worth it.
A study published in the journal Epidemiology in November 1998 found that light to moderate drinkers had the lowest risk of death compared with nondrinkers. Those who drank between one and seven alcoholic beverages a week experienced a 20 percent reduction in overall mortality.
When the researchers looked more closely at why light to moderate alcohol drinkers had less risk of death, they found that this group experienced a reduction in death from heart disease, thereby suggesting that the moderate alcohol consumption could have some protective benefits for the heart.
The Final Word on Alcohol
Based on the many studies finding that moderate alcohol consumption can have a heart-protective benefit, many experts said that moderate drinkers should not worry about this latest research finding an increased risk in cancer.
"A small decrease in [cardiovascular] risk more than compensates for an increased risk of rare cancers," said Dr. Alan Kristal, member and associate head of the Cancer Prevention Program at the Fred Hutchinson Cancer Research Center in Seattle. "You have to die of something, and no doubt how you live affects what you die [from], but not 'if' and maybe not 'when.'"