another reason not to: binge drinking raises breast cancer risk
Binge drinking raises cancer risk [BBC News]
A study of 17,647 nurses found twice the risk of breast cancer in women who drank 22-27 drinks a week compared with those who drank one to three drinks.
The risk was greatest when drinks were consumed in a short period, reported the European Journal of Public Health.
Experts said women should try and limit the amount of alcohol they drank.
Women in the study were aged over 44, and most drank a moderate amount of alcohol.
A drink was classed as a bottle of beer or a glass of wine or spirit, which in Denmark is roughly 12g of alcohol.
Even small amounts of alcohol can increase the risk of breast cancer Dr Alison Ross, Cancer Research UK
In the UK, a unit of alcohol is around 8g.
More than a quarter of the women drank more than the recommended 14 drinks a week.
One in 10 were week-day binge drinkers, having more than four drinks a day and 13% were weekend binge drinkers, defined as more than 10 drinks between Friday and Sunday.
There was a 2% increased risk of breast cancer for each additional drink consumed, but at weekends there was a 4% increased risk with each additional drink.
The researchers said this was because more drinks were likely to be consumed in a weekend drinking session.
Drinking 22-27 drinks over the course of the week was linked to a 130% increased risk.
Those who drank excessively on just one day during the week increased their risk by 55%.
The researchers said higher alcohol intake may increase levels of oestrogen - a hormone associated with the development of breast cancer.
Dr Lina Morch a researcher in the Centre for Alcohol Research in Denmark, who led the study, said: "What our study suggests is that the total amount of alcohol consumed has a detrimental effect on the risk of breast cancer, but also the drinking pattern seems to have an impact on the risk.
"When more drinks are consumed within a limited time frame the concentration of alcohol in the blood peaks, which we suppose is more harmful than when the same amount of alcohol is consumed over longer time periods."
She advised women to drink moderate amounts of alcohol and to avoid consuming lots of drinks in one day.
EARLY VIEW: ABSTRACT: Alcohol drinking, consumption patterns and breast cancer among Danish nurses: a cohort study [European Journal of Public Health]
Background: The aim of this study was to analyse the impact of alcohol intake and drinking pattern on the risk of breast cancer.
Methods: A total of 17,647 nurses were followed from 1993 until the end of 2001. At baseline participants completed a questionnaire on alcohol intake and other lifestyle-related factors. Data were analysed using Cox's proportional hazard model.
Results: During follow-up 457 women were diagnosed with breast cancer. The relative risk of breast cancer was 2.30 [Confidence interval (CI): 1.56-3.39] for alcohol intake of 22-27 drinks per week, compared to 1-3 drinks per week. Among alcohol consumers, weekly alcohol intake increased the risk of breast cancer with 2% for each additional drink consumed. Weekend consumption increased the risk with 4% for each additional drink consumed friday through sunday. Binge drinking of 4-5 drinks the latest weekday increased risk with 55%, compared with consumption of one drink. A possible threshold in risk estimates was found for consumption above 27 drinks per week.
Conclusions: For alcohol consumption above the intake most frequently reported, the risk of breast cancer is increased. The risk is minor for moderate levels but increases for each additional drink consumed during the week. Weekend consumption and binge drinking imply an additional increase in breast cancer risk.