A glass of wine a day can boost survival chances of women with breast cancer by up to a fifth, scientists claim.
In the largest study of its kind, researchers from the University of Cambridge found that those who drink in moderation are more likely to recover from the illness than those who abstain.
The findings are somewhat unexpected because drinking alcohol is considered to be one of the leading causes of breast cancer among healthy women, the Daily Mail reported.
One explanation is that the chemicals in alcohol which damage healthy cells also have the same effect on cancerous cells.
There are currently no specific guidelines in the UK for breast cancer patients on alcohol consumption, but healthy women are advised to drink no more than 14 units a week.
Many women with cancer stop drinking in the hope it will boost the success of their treatment.
Researchers looked at 13,525 women with breast cancer for an average of seven years.
They recorded the average weekly alcohol intake for each patient as well as their body mass index.
Women who drank seven units a week – three and a half small glasses of wine – were 10 per cent more likely to survive than those who had nothing.
The odds increased to 20 per cent if women drank 14 units a week.
“What our study says is that it is reasonable, if you’re diagnosed with breast cancer, to enjoy the occasional drink of alcohol,” Dr Paul Pharoah, of the university’s Department of Oncology, said.
Although drinking alcohol seems to make a big difference to women’s survival odds, the scientists pointed out that the overall change was small.
This was because there were many other factors affecting the success of treatment including how early the illness was diagnosed, the woman’s age and the particular type of breast cancer.
Experts commenting on the study also pointed out that alcohol was only beneficial once a woman had been diagnosed with breast cancer.