The effect on cancer risk of drinking a pint a day
Drinking a pint of beer, a large glass of wine or a couple of measures of spirits a day increases the risk of liver and bowel cancer by a fifth, according to researchers.
Research by the World Cancer Research Fund (WCRF) has shown that two units of alcohol a day increases the risk of bowel cancer by 18 per cent and the risk of liver cancer by 20 per cent. In the UK every year, liver cancer kills about 3,000 people and more than 36,000 people are diagnosed with bowel cancer.
In 2007, the WCRF produced a report looking at the effect on cancer incidence of food, drink, and physical activity. The report looked at all available research on cancer prevention. Over the course of six years, researchers from nine universities reviewed thousands of studies and made a series of recommendations, including a limit on alcohol consumption. From an initial 500,000 studies, 7,000 were deemed to meet the standards required for inclusion in the report. It found there was convincing evidence that alcoholic drinks were a cause of bowel cancer and probably a cause of liver cancer.
WCRF science programme manager Dr Rachel Thompson has since reviewed the evidence in the report. Dr Thompson converted the relative risks, which are presented in the report in units 'per 10g per day', into more meaningful terms.
She calculated that having one pint of beer a day, or two smaller drinks containing more than 10g of alcohol each, increases the risk of bowel cancer by 18 per cent and the risk of liver cancer by 20 per cent.
However, research suggests that few people understand the risks. In Britain, 64 per cent of people are unaware of the link between alcohol and cancer, she said. 'For cancer prevention, WCRF recommends not drinking alcohol at all,' Dr Thompson added. 'Modest amounts of alcohol may have a protective effect for heart disease but the benefits only outweigh the risk in those particularly at risk of heart disease, such as men aged over 40 and postmenopausal women.' The WCRF recommends that if people drink, they should limit themselves to two drinks a day for a man or one for a woman, she added.
Ed Yong, health information manager at Cancer Research UK, said that the WCRF analysis was consistent with other research into links between alcohol intake and cancer risk. 'The WCRF report was comprehensive,' he said. 'It fits with established evidence that drinking more than three units of alcohol a day can significantly increase the chance of developing cancer - particularly in the mouth, oesophagus, breast, bowel and larynx.'
WCRF/AICR Expert Report. Food, Nutrition, Physical Activity and the Prevention of Cancer: a Global Perspective
Originally published in the March 2009 edition of MIMS Oncology & Palliative Care.