Drinking a glass of wine at a lower strength could cut bowel cancer risk
Swapping a daily glass of wine for a slightly weaker alternative could be enough to lower the risk of some cancers, a charity suggests.
Studies suggest that people who drink wine with an alcohol content of 10% rather than 14% might benefit, says the World Cancer Research Fund.
The charity called for more low-alcohol wines and beers to be available for sale.
An industry expert said UK consumers were asking for "lighter" wines.
The calculation was based on figures in a 2007 report which looked at the evidence for a link between alcohol consumption and cancer.
That report recommended that men should have no more than two drinks a day, and women no more than one.
The figures used to reach that conclusion were detailed enough to reveal the likely extra risk posed by each extra 10 grams of alcohol - just over one unit - regularly consumed.
From this, scientists calculated that, in theory, a person drinking one large 250ml glass of wine a night would have a 7% lower risk of bowel cancer if they normally drank 10% strength wine rather than 14%.
This is only a modest decrease of risk for an individual, and there is no clear evidence about how long someone would need to substitute weaker wine for their usual tipple in order to reap this benefit.
However, the charity said that for every 100 people who did it, one case of bowel cancer would be avoided.
While the detailed studies only applied to bowel cancer, it said that there was no reason to believe that the risk of other cancers linked to alcohol, such as throat, oesophageal and breast, would not respond in a similar way.
Dr Rachel Thompson, science programme manager for WCRF, said: "From a cancer prevention point of view it is best not to drink at all.
"But we have to be realistic, and the fact is that many people in the UK enjoy a drink and see it as part of their social life.
"Making this change might seem quite minor to do, but it could have a real impact on cancer risk.
"If everyone who drinks 14% wine at the moment switched to lower-alcohol wine tomorrow, for example, it is likely hundreds of cancer cases in the UK a year could be prevented."
She said that while it was possible to find weaker alternatives, most wines still had a strength of 13% or 14%, and called on retailers to make more weaker wines available.
She said that beer drinkers could also expect similar benefits if they switched from premium strength to lower-alcohol brands.
Dr Peter Sasieni, a researcher in cancer prevention statistics from Queen Mary's University of London, said that while it was difficult to be precise about how a decision to change drinking lifestyle would affect individual cancer risk over the years, a move to lower-strength wines could offer protection.
He said: "Given that alcohol can be bad for you even in fairly low amounts, that would start to suggest that people should take note of the percentage of alcohol in their wine.
"If they are enjoying the 10% glass as much as the 14% one, it would make sense to opt for the 10%."
Gavin Partington, from industry body the Wine and Spirit Trade Association, said that the rise in the alcohol content of the wine sold in the UK was due to the increasingly popularity of southern hemisphere wines from countries such as Argentina, Chile and Australia, which, due to the climate, tended to have a higher content.
He said: "What we are noticing is that 'lighter' wines - such as Pinot Grigio - seem to be becoming far more popular, and these tend to have a lower alcohol content.
"This means that it is likely that more of these lower alcohol wines will be more available in the supermarket, simply as a product of changing consumer demand."