Three drinks a day 'raises breast cancer risk by 30 percent'

Drinking alcohol is known to increase the chance of developing breast cancer but now scientists know by how much.

U.S. researchers carrying out one of the largest studies to investigate the relationship found it is alcohol itself and the amount a person consumes that is critical - rather than the type of drink.

More follows...

Women who drank between one and two alcoholic drinks per day increased their risk of breast cancer by ten per cent compared with those who consumed less than one drink each day, the researchers found.

The risk jumped by 30 per cent in women who consumed more than three drinks a day, says the study presented at the European Cancer Conference in Barcelona.

Researcher Dr Arthur Klatsky of Kaiser Permanente, a leading health plan organisation based in California, said: 'Studies have consistently linked drinking alcohol to an increased risk of female breast cancer.

'But until now there has been little data, most of it conflicting, about an independent role played by the choice of beverage type. A 30 per cent increased risk is not trivial.

'To put it in context, it is not much different from the increased risk associated with women taking oestrogenic hormones.

'Incidentally, in previous research completed at Kaiser Permanente, we have found that smoking a pack of cigarettes or more per day is related to a similar increased risk of breast cancer of 30 per cent.' As a result, heavy drinking might contribute an extra five per cent of breast cancer cases attributable to the habit.

Other studies have shown that light to moderate alcohol use can protect against heart attacks.

Dr Klatsky said the heart protection probably comes from alcohol-induced 'good' cholesterol, reduced blood clotting and decreased diabetes risk. But the trigger for breast cancer is the ethyl alcohol content found in all types of drink, he said.

In the UK, a major study five years ago showed each drink raised a woman's breast cancer risk by at least six per cent. The Cancer Research UK study estimated around one in 20 cases of breast cancer in the UK each year can be blamed on drinking - around 2,000 cases in total.

The study suggested the risk could be higher in other countries where drinks tend to be served in larger measures.

In the latest U.S. research, the drinking habits of more than 70,000 women from a variety of ethnic backgrounds were examined between 1978 and 1985.

By 2004, nearly 3,000 of the women were diagnosed with breast cancer.

The team reached its conclusions by checking preferences for types of alcohol and how much each woman consumed.

j.hope@dailymail.co.uk