CHICAGO (AP) — Whether sipping beer, wine or whiskey, women who drink just three alcoholic beverages a week face slightly higher chances for developing breast cancer compared with teetotalers, a study of more than 100,000 U.S. nurses found.
The link between alcohol and breast cancer isn't new, but most previous studies found no increased risk for breast cancer among light drinkers. The new research provides compelling evidence because it followed so many women for up to almost 30 years, experts said.
Still, the study only shows an association between alcohol and breast cancer; it doesn't prove that drinking causes the disease. There could be some other reason light drinkers appeared to be at higher risk — maybe they were less active than nondrinkers or had unhealthy diets, said Dr. Susan Love, a breast cancer expert and author who runs a Santa Monica, Calif.-based research foundation.
Women in the study who averaged three to six drinks a week throughout the study had a 15 percent higher chance of developing breast cancer than nondrinkers. That risk means, for example, that among women in their 50s, who on average face a 2.38 percent risk for breast cancer, light drinking would result in 4 additional cases of breast cancer per 1,000 women
Risks increased by 10 percent for every 10 grams of alcohol consumed daily. That's equal to a little less than one 12-ounce bottle of beer, a 4-ounce glass of wine or a shot of whiskey. The increasingly elevated risks were a little higher than seen in other research. It made no difference whether the women drank liquor, beer and wine.
Given research suggesting that drinking moderate amounts of alcohol including red wine may protect against heart disease, deciding whether to avoid alcohol is a personal choice that should be based on a woman's other risks for breast cancer and heart disease, the researchers said.
The study appears in Wednesday's Journal of the American Medical Association. It began in 1980, asking healthy, mostly white nurses aged 30 to 55 to fill out periodic questionnaires about lifestyle and risk factors for cancer and heart disease. Follow-up ended in 2008 or when women died or were diagnosed with cancer.
The researchers took into account other cancer risk factors, including age of menstruation and menopause, family history, weight and smoking, and still found a link with alcohol.
The strongest risks were seen with cumulative consistent alcohol use throughout the study. Increased risks also were seen in binge drinkers — women who consumed at least three drinks daily in a typical month. The results do not apply to women who may have partied hard during week-long vacations but otherwise rarely drank, said lead author Dr. Wendy Chen, a researcher at Brigham and Women's Hospital and Dana-Farber Cancer Institute and an assistant professor at Harvard Medical School.
"No one should feel guilty about one particular week or two," Chen said.
The results don't mean women can avoid breast cancer by not drinking, and they don't answer whether women can lower their risk if they stop drinking, said breast cancer specialist Dr. David Winchester, chief of surgical oncology with NorthShore University HealthSystem in Evanston, Ill.
Drinking alcohol "is definitely not one of the leading explanations" for why breast cancer develops, he said. "It's one of many contributing factors."
Cancer researcher Jo Freudenheim noted that the risks linked with alcohol, shown in this study and others, are much lower than those associated with smoking and lung cancer.
The study "doesn't change the picture; it just brings it into a little sharper focus," said Freudenheim, head of social and preventive medicine at the University at Buffalo.
<한글기사>
술적게마셔도 유방암 위험 15% 높아
알코올이 여성호르몬 에스트로겐 혈중 수치 올려
술을 많이 마시지 않아도 유방암 위험이 다소 커질 수 있다는 새로운 연구결과가 나왔다.
미국 하버드 대학 의과대학 브리검 여성병원의 웬디 천(Wendy Chen) 박사는 간호사 건강연구(Nurses' Health Study)에 참여하는 여성 10만6천명을 대상으로
1980- 2008년 사이에 4년에 한 번씩 음주량과 유방암 발병 여부를 조사분석한 결과 알코올 을 매일 5-9.9g(1주일로는 포도주 3-6잔) 섭취한 여성이 술을 전혀 또는 거의 마시 지 않는 여성에 비해 유방암 발생률이 평균 15% 높은 것으로 나타났다고 밝힌 것으 로 헬스데이 뉴스가 1일(현지시간) 보도했다.
하루 알코올 섭취량이 30g인 여성은 유방암 위험이 51% 높았다고 천 박사는 밝혔다.
이 결과는 연령, 유방암 가족력, 체중, 흡연 등 다른 유방암 위험인자들을 고려한 것이다.
천 박사는 그러나 이는 장기간에 걸쳐 지속적으로 섭취한 알코올의 누적량을 말하는 것으로 휴가나 휴일 같은 특정한 시점에 이따금 과음한 것은 해당하지 않는다 고 말했다.
유방암 위험이 음주와 연관이 있는 것은 알코올이 여성호르몬 에스트로겐의 혈중 수치를 올리기 때문이라고 천 박사는 설명했다. 에스트로겐이 많으면 유방암 위 험이 증가하는 것으로 알려져 있다.
이 연구결과는 미국의사협회 저널(Journal of American Medical Association) 최신호(11월2일자)에 실렸다.
