Alcohol and Risk for Breast Cancer

Featured

Alcohol and Risk for Breast Cancer

Health 30 November 2007

A new study linking alcoholic beverages to breast cancer has left many women in a panic. Should you give up evening cocktails? Should you stop cooking with wine? The latest data, gathered by researchers at Kaiser Permanente in Oakland, Calif., are based on the drinking habits of more than 70,000 women who supplied dietary information during health examinations between 1978 and 1985. The truth is, the findings aren’t nearly as scary as they sound. The highest risk of breast cancer was found among women who consumed on average more than three alcoholic beverages a day. Among those who consumed less, one drink a day didn’t increase breast cancer risk at all and two drinks a day raised the odds only slightly. The main finding of the new research is that a woman’s overall risk was the same whether she drank white wine, red wine, beer or spirits. The findings about breast cancer are consistent with those from other large studies of women and alcohol, including the well-known Nurses’ Health Study at Harvard University. Most research shows that for both men and women the benefits of moderate alcohol consumption usually outweigh the risks. Alcohol is linked to a lower risk of heart attack, diabetes, dementia and stroke, and a slightly higher risk of colon cancer. Two drinks a day raises the risk of oral cancer and esophageal cancer, but those cancers are so rare that for most people the individual increase in risk is not worrisome. For men, moderate drinking translates into about two servings of alcohol a day, and for women just less than one. A serving is typically defined as a 5 ounce glass of wine, 12 ounces of beer, or a shot (1.5 ounces) of distilled spirits. Much of the research on alcohol’s risks and benefits comes from studies that observe people over time, rather than controlled clinical trials, which are more reliable. So while the evidence for moderate consumption of alcohol is strong, it isn’t conclusive. Public health officials have long advised that if you don’t drink now, the potential health benefits aren’t a reason to start. And for people on certain medications or with substance abuse problems, any amount of alcohol is a bad idea. The question for most women now, though, is whether the apparent health benefits associated with moderate drinking outweigh the slight increase in breast cancer risk. Scientists don’t know how exactly alcohol contributes to breast cancer, but they know levels of circulating estrogen tend to be higher in women who drink. The Kaiser study found a 30 percent increase in risk with three drinks a day. A pooled analysis by Harvard researchers of six studies on alcohol and breast cancer shows that a woman’s risk increases by about 9 percent for every 10 grams of alcohol a day that she drinks. In the United States, a typical drink delivers about 12 grams to 14 grams of alcohol. That means just two drinks a day might increase a woman’s risk for breast cancer by 27 percent. That’s about the same increase associated with long-term use of estrogen or smoking a pack a day of cigarettes. But before you panic, remember these scary percentages translate into very small risks for the individual woman. A typical 50-year-old woman has a five-year breast cancer risk of about 3 percent. If her risk jumps by 30 percent, her individual risk is still only about 4 percent. (October, 2007- Kaiser Permanente Division of Research/ contact Danielle Cass)

Environment

Environment Articles