A new study involving over 330,000 women in 10 European countries has confirmed that drinking alcohol increases the risk of developing breast cancer.

A total of 334,850 women aged between 35 and 70 took part. Among these, almost 12,000 were diagnosed with breast cancer over an 11-year period.

The study was carried out by Spanish researchers and their results confirmed previous studies that suggested a link between alcohol intake and breast cancer.

"A woman's average risk of being diagnosed with breast cancer increases by 4% with each additional 10 grams per day of alcohol. In other words, a daily intake of one glass of wine or beer - or less - would correspond to a risk value of one. However, if we increase our intake to two daily glasses of wine or beer, our risk would rise by 4%," the scientists said.

Meanwhile, an increase of up to 15 grams per day is linked to an almost 6% increased risk of breast cancer.

In Ireland, a standard drink has around 10 grams of pure alcohol in it. A standard drink is a pub measure of spirits, a small glass of wine or a half pint of beer.

The study also found that the longer a woman had been consuming alcohol, the greater the breast cancer risk, particularly if she began drinking before her first pregnancy.

''Alcohol intake is a breast cancer risk factor that can be changed by a personal decision to form healthy habits. Hence, women must be advised and forewarned of the possibility they have to control this factor,'' the researchers commented.

Details of these findings are published in the International Journal of Cancer.