A single pint of beer a day raises the risk of prostate cancer, say Australian researchers. Alcohol has long been known to be a risk factor for several types of cancer, including breast and digestive cancers, but its role in prostate cancer was unclear.

A new study published in BMC Cancer however, found a significant relationship between alcohol consumption and the risk of prostate cancer, and the more a person drank, the higher their risk.

Part of the problem with many previous studies involved what scientists call "abstainer bias." Former drinkers, including people who may have drunk heavily in the past but quit due to health reasons, are included in the group of nondrinkers.

The practice gave drinkers a false sense of security because previous studies disguise the association between alcohol intake and health problems like prostate cancer by making drinkers "look good" in comparison with a group containing unhealthy former drinkers.

When researchers controlled for abstainer bias in their analysis of 27 studies, they found a significant connection between the amount of alcohol consumed and the risk of prostate cancer.

When men who drank up to two drinks a day — about a pint of beer or two glasses of wine — were compared to those who never drank, their risk rose 23 percent.

"This new study contributes to the strengthening evidence that alcohol consumption is a risk factor for prostate cancer, said study co-author Dr. Tim Stockwell.

According to the National Cancer Institute, about 1 in 7 American men will be diagnosed with prostate cancer during their lifetime. Last year, 220,800 were diagnosed and about 27,540 died from the disease.