A review of research on alcohol and breast cancer has found that just one drink a day can increase the risk of breast cancer by five per cent. Women drinking \'heavily\' by having three or more drinks a day are up to 50 per cent more likely to develop breast cancer than those who abstain, it was found. It could mean that thousands of cases of breast cancer in Britain each year are caused by alcohol. The link between breast cancer and alcohol is already known but it has not been clear if there was an the increased risk with low levels of consumption or a \'safe\' threshold, below which there was no effect on breast cancer. There are around 48,000 women diagnosed with breast cancer in Britain each year and just under 12,000 women with the disease die annually. The analysis of 113 research papers was published in the journal Alcohol and Alcoholism. The researchers from the University of Heidelberg in Germany and the University of Milan, in Italy, wrote in the journal: \"Since several populations show a high prevalence of light drinkers among women, even the small increase in risk we reported — in the order of five per cent — represents a major public health issue in terms of breast cancers attributable to alcohol consumption.\" In the research, a drink was defined as 10 to 12 grams of ethanol, the equivalent of up to 1.5 UK units, or around one 125ml glass of average strength red wine or a pint of lager. The researchers found that the more women drank the higher their risk of breast cancer, and calculated that each 10g of alcohol per day was linked to a ten to 13 per cent increased risk of cancer. For every 200 women, 20 are expected to develop breast cancer during their lifetime. If they all drank 1.5 units every day, an extra one woman would develop cancer because of alcohol, the research suggests. Lead author Prof Helmut Seitz wrote: \"Since there is no threshold level of ethanol for breast cancer risk, the breast is one of the most sensitive organs for the carcinogenic action of alcohol. Healthy women should not exceed one drink a day (equivalent to 10–12g of ethanol). \"Women at an elevated risk for breast cancer such as those with a positive family history, or conditions associated with an increased breast cancer risk should avoid alcohol or consume alcohol only occasionally.\" It is thought alcohol affects the female hormone oestrogen which can fuel certain forms of breast cancer. Sarah Williams, health information officer at Cancer Research UK, said: “Research has already shown that the risk of breast cancer increases the more alcohol a woman drinks. \"But this new study adds to the evidence that drinking even small amounts of alcohol – about one drink a day – can slightly increase the risk of breast cancer. \"Women can help reduce their risk of breast cancer by reducing the amount of alcohol they drink, keeping a healthy weight, and being physically active.”