They are the problem drinkers missed by government efforts to curb alcohol misuse – women, often middle-class and professional, who share a bottle of wine with a partner over dinner each night, putting their health at risk.
Unnoticed because they do not cause a social nuisance or public disorder, women who quietly drink three or more glasses of wine, or equivalent, a day increase their risk of breast cancer by up to half, research shows.
Alcohol is known to increase the risk of several cancers, in both sexes, including bowel cancer. But breast tissue is thought to be particularly sensitive to its carcinogenic effects according to a review of research by Helmut Seiz, of the University of Heidelberg, Germany, and colleagues.
Women who consume one alcoholic drink a day have an increased risk of breast cancer of 4 per cent, in line with previous findings, based on an analysis of 113 studies involving 77,000 light drinkers. Among heavy drinkers, defined as three or more drinks a day, the risk is increased to 40 to 50 per cent. Overall, alcohol drinking accounts for one in 20 cases of cancer in northern Europe and one in 10 in countries such as Italy and France, where drinking is more widespread among women.
Breast cancer has soared in recent decades with new cases doubling since the early 1970s, partly driven by the rise in alcohol consumption. It is now the commonest cancer, with almost 49,000 cases and 12,000 deaths a year, despite affecting only one sex.
However, it is less common than heart disease and strokes, which together kill 200,000 people a year – and alcohol is known to protect against these diseases. In women, as little as one drink a week cuts the risk of heart attack and stroke by 36 per cent according to a 2007 European study.
The upshot is that light drinking is overall protective – but heavier drinking is associated with rapidly increasing risks. Experts say weighing up these risks is a matter of personal choice. Although heart disease is more common, cancer is more feared. Women with a family history of heart disease may feel differently from those with a history of cancer.
Three times more alcohol is now consumed per head as in the 1950s and it is estimated to cause 30,000 to 40,000 deaths a year. In addition to bowel cancer and breast cancer, there is also evidence that alcohol increases the risk of cancers of the liver, oesophagus, mouth, pharynx and larynx. In total, scientists estimate alcohol causes 20,000 cases of cancer a year.
The authors of the latest study, published in Alcohol and Alcoholism, suggest the effect of alcohol on the breast may be hormonal by raising levels of oestrogen. But they show no acknowledgment of the fact that many people enjoy a drink which plays an important part in their social lives.
Increases risk of breast cancer by 4 to 5 per cent.
Increase the risk by 25 to 35 per cent.
Increase the risk by 40 to 50 per cent.