Alcohol doubles rectal cancer risk

Drinking more than 14 units of beer or spirits a week may increase the risk of rectal cancer, according to a study.

But Danish researchers spotted no such effect in wine drinkers.

The finding adds more confusion to evidence about alcohol and its effect on colorectal cancer.

While some studies have suggested a weak link between drinking more than the recommended limit and colorectal cancer, there is no firm evidence.

This study, from the Centre for Alcohol Research in Kobenhavn, finds no link between alcohol consumption and colon cancer.

However, drinkers appeared to more than double their risk of rectal cancer.

Wine ingredient

The researchers suggested that one interpretation of the evidence was that while drinking too much alcohol could increase the risk of rectal cancer, wine drinkers experienced benefits that cancelled this out.

"The present study provides evidence of a causal relationship between alcohol and rectal cancer," they wrote.

Safe limits

In the UK, the government recommends that men drink no more than three to four units of alcohol a day, and women two to three.

A pint of beer is roughly two units, while a glass of wine or measure of spirits is one unit.

This means that a "moderate" drinker in these terms might still increase his or her rectal cancer risk, if the Danish study is correct.

Cancers of the lower digestive system account for 34,000 cases among Britons each year, and approximately 20,000 deaths.

The cancer can be hard to treat unless it is caught early, and often does not display easily-noticed symptoms until it is well-established.

Researchers have already noticed a link between the disease and high-calorie diets - and studies seem to suggest that eating plenty of fibre, and fruit and vegetables, may protect someone from the disease.

However, people are urged to be vigilant for early signs of the disease, including blood in the stools.

Longer survival

The study was published in the journal Gut, which also carried a paper suggesting that patients who have already got colon cancer survive longer if on a high calorie diet.

Given that high-calorie diets have already been linked to the development of the disease, the authors of the paper admitted it was a surprising finding.

The team, from the Institute for Food and Nutrition in Paris, put forward the theory that patients who had developed colon cancer because of a high-calorie diet might suffer from a form of the disease that was more easily treatable, or that patients with a high "energy store" tended to live longer once they had the disease.