Light Drinking Lowers Risk of Some Cancers

When it comes to lowering the risk of developing cancer, a new study finds that a little bit of alcohol goes a long way. Researchers found that people who drink one alcoholic beverage a day have a lower risk of cancer than nondrinkers, while those who drank two to three glasses a day shared the same risk as nondrinkers. People who consumed more than three drinks daily, however, suffered a much higher risk.

The research, published in the American Journal of Epidemiology, looked at the rate of cancer among more than 323,000 Americans and examined possible links to drinking habits. The authors, epidemiologists from the National Institute on Alcohol Abuse and Alcoholism, along with noted Harvard alcohol researcher Kenneth Mukamal, were trying to identify singular risk factors for different types of cancer.

They compared alcohol consumption to rates of breast, colorectal, lung and prostate cancer in several hundred thousand participants in the larger National Health Interview Survey. The authors recorded 8,000 cancer deaths during that time, which factored into their results.

Their findings: For those who consume alcohol lightly, that is, approximately one drink daily, there is a 13 percent decrease in cancer risk compared to nondrinkers. Moderate drinkers, up to three drinks daily, showed an even risk to nondrinkers.

However the researchers chose not to mention this in the abstract. Instead, the authors focused on the negative results for people who consume alcohol in higher amounts. They found that heavy drinkers—more than three drinks daily—were 27 percent more likely to develop cancer than nondrinkers.

When they separated by gender the risk gap widened—men who drink heavily are at a 41 percent greater risk while women are at a 20 percent greater risk. "Our study reinforces the importance of considering alcohol quantity and frequency in studies of cancer mortality," the authors state in their conclusion.

Many past studies of possible links between some forms of cancer and alcohol have focused on how much subjects drank weekly or monthly. But scientists have admitted there may be a difference between someone who drinks one daily glass of wine and someone who drinks seven every Friday night.

This study does measure daily consumption. However, the scientists did not separate the results by beverage type. That, along with the results for those who drink lightly, is attracting the attention of other experts in the field. In other studies that have analyzed data by beverage type, wine sometimes shows different results than beer and spirits.

"A potentially important omission is the failure to present results by the type of beverages consumed," states a follow-up critique from the International Scientific Forum on Alcohol Research, a cooperative of alcohol-research experts from various medical and research universities. "While such information was not available for all subjects, with a dataset this large there should have been adequate numbers of subjects consuming different beverages to comment on beverage-specific effects."