Middle-aged women who drink just one glass of wine a day could double their risk of a common type of breast cancer, scientists warn.

According to the U.S. research, even those who drink just seven units a week - half the recommended safe level - have a much greater chance of developing lobular cancer than those who don’t drink at all.

Experts have already warned that excessive drinking is causing a global rise in breast cancer.

In Britain alone the number of cases has risen by 80 per cent in the past 30 years. Over the same period, alcohol consumption has almost doubled.

Lobular cancer is the second most common form of breast cancer. It affects 20,000 British women every year and accounts for a fifth of all tumours. Women aged 45 to 55 are most at risk.

For their study, scientists looked at the recent drinking habits of almost 90,000 women who had gone through the menopause.

Those who drank seven or more units a week were 1.82 times as likely to develop the cancer once they reached the menopause.

The researchers, from the Fred Hutchinson Cancer Research Centre, in Seattle, are not sure why alcohol appears to cause tumours to develop.

But they believe it raises the levels of the hormone oestrogen, which has previously been linked to increased risk of breast cancer.

However, alcohol did not appear to increase the risk of ductal breast cancer - the most common type of the illness, concluded the study, published in the Journal of the National Cancer Institute.

The authors, led by Dr Christopher Li, said: ‘We found that women who drank one or more drinks per day had about double the risk of lobular type breast cancer, but no increase in their risk of ductal type breast cancer.

‘It is important to note that ductal cancer is much more common than lobular cancer, accounting for about 70 per cent of all breast cancers, whereas lobular cancer accounts for only about 10 to 15 per cent of cases.’

Official guidelines say that women should drink no more than 14 units a week.

A small 125ml glass of wine contains about a unit of alcohol, depending on its strength.

Two years ago, research found that two large 250ml glasses of wine a day can raise the risk of breast cancer by more than half.

Dr Rachel Thompson, of the World Cancer Research Fund, said: ‘Looking at all the evidence, there is convincing evidence that alcohol increases risk of breast cancer.

‘We estimate that about one in five cases of breast cancer in the UK could be prevented through people cutting down the amount they drink.

‘As well as breast cancer, there is also strong evidence that alcohol increases risk of bowel cancer, liver cancer, cancer of the mouth, pharynx and larynx, and oesophageal cancer.’

Henry Scowcroft, of Cancer Research UK, said: ‘This new study confirms that breast cancer is more common amongst women who drink alcohol regularly - and the more they drink, the more this risk increases.

‘The study also confirms that alcohol increases breast cancer risk by affecting the levels of oestrogen in our bodies. Our researchers have estimated that alcohol is linked to around 5,000 cases of breast cancer every year.’

Breast cancer survival rates have improved considerably over the past decade but the disease still claims 12,000 lives here every year.

Earlier this month, a report blamed our culture of overeating and binge drinking for soaring breast cancer rates.

Scientists say four out of every ten breast cancer cases in Britain could be prevented if women maintained a healthy weight, drank less alcohol and took more exercise.

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By Sophie Borland
Daily Mail