Cut drinking to reduce risk of cancer, says new guidance

New guidelines from all four UK chief medical officers warn that drinking any level of alcohol raises the risk of a range of cancers.1

An expert advisory group examined the evidence from 44 systematic reviews and meta-analyses published since its 1995 Sensible Drinking report and concluded that there was strong evidence that the risk of a range of cancers, particularly breast cancer, increased directly in line with consumption of any amount of alcohol (table⇓).

The guidelines came out at the same time as a report from the Committee on Carcinogenicity, a UK non-statutory advisory body, which said that between 4% and 6% of all new cancers in the UK in 2013 were caused by alcohol consumption.2 This report said that research now showed a statistically significant increase in the risk of cancer at low, medium, and high levels of alcohol intake for cancers of the oral cavity and pharynx, oesophagus, and breast (in women). At medium and high levels of alcohol intake (over 1.5 units a day) there was an increased risk of cancers of the larynx and colorectum, and at high levels of intake (over 6 units a day) there was an increased risk of cancers of the liver and pancreas.

Although the chief medical officers’ guidelines emphasised that there was no “safe” level of drinking, to keep risks to health low men and women should not drink more than 14 units of alcohol a week. This is roughly equivalent to six pints of average strength beer. The previous daily guidelines were 21 units for men and 14 for women.

The guidelines say that these units should not be “saved up” but spread over three or more days, as people who have one or two heavy drinking sessions increase the risk of death from injury and long term illness. They recommend that a good way to reduce alcohol intake is to have “several” alcohol free days a week but do not specify how many. The guidelines do not set a number of units that should not be exceeded on a single day, but the expert group may produce guidance on this at a future date.

The advice to pregnant women has also been updated to make it clear that no level of alcohol is safe during pregnancy. The evidence review also found that any benefits of alcohol in protecting against ischaemic heart disease applied only to women aged 55 or over. The greatest benefit was seen when these women limited their intake to around five units a week, equivalent to two standard glasses of wine.

The Committee on Carcinogenicity’s report said that all types of alcoholic drink could cause cancer, with little difference between wine, beer, and spirits. David Phillips, the committee’s chair, said, “The risk of getting cancer increases the more alcohol a person drinks. Even alcohol intake of below 1.5 units a day, or 10.5 units a week, gives an increased risk of cancer of the mouth, throat, and gullet. This level of drinking also increases the risk of breast cancer in women. When alcohol consumption is above around 1.5 units a day, or 10.5 units a week, there is an increased risk of cancer of the voice box and large bowel. If alcohol intake is above about six units a day, or 42 units a week, there is an increased risk of cancer of the liver and pancreas.”

Sally Davies, England’s chief medical officer, said, “Drinking any level of alcohol regularly carries a health risk for anyone, but if men and women limit their intake to no more than 14 units a week it keeps the risk of illness like cancer and liver disease low.”

John Holmes, senior research fellow at the University of Sheffield’s Alcohol Research Group, which was commissioned by Public Health England to provide an analysis of the evidence on health risks associated with different levels and patterns of drinking, commented, “While many scientific studies suggest moderate drinking can be good for your heart, researchers are increasingly concerned that problems with those studies mean any protective health effects which alcohol may provide have been substantially overestimated.”

He added, “Our analyses did take evidence of protective health effects at face value but still found that, after accounting for the health risks of drinking, any remaining protective effect was small, associated with very low levels of alcohol consumption, and only likely to benefit specific groups in the population even if it was genuine.”