Moderate alcohol intake and cancer: the role of under-reporting

A large US cohort study in 129,987 persons suggests that the apparent increased risk of cancer among light-moderate drinkers is substantially due to underreporting of intake.

Although experts agree that heavy consumption of alcohol is related to increased risk of several cancer types, the role of light-to-moderate drinking is less clear, said Dr Arthur Klatsky of Kaiser Permanente Medical Care Program, Oakland, CA, USA. Some studies have suggested there is a connection, while others have found no link.

The results of the new analysis suggest that any apparent relationship between cancer risk and light-to-moderate drinking, meaning up to 2 standard sized drinks per day for men and one for women, may be largely an artifact of under-reporting—that is, lying about drinking amount.

"If some heavy drinkers answer surveys saying that they only drink lightly, the effects of heavy drinking then appear to be related to light-to-moderate intake," Dr Klatsky explained. "Our analysis inferentially supports this factor in our study population and it is probably applicable to most studies, as under-reporting of alcohol consumption is surely prevalent."

"There are plenty of reasons why people need to avoid heavy drinking, but these do not generally apply to light drinking," Dr Klatsky said. "All concerns about the risks of light drinking need to be balanced by the evidence that persons at risk of heart disease benefit from lighter alcohol drinking. This --with plenty of exceptions-- means most persons over 50."