- Cancer risk rises with each drink, but the link between mortality and alcohol is more J-shaped, a new study finds
- “The reduced risk in light drinkers was surprising,” a researcher says
- For cancer risk, “the more you drink, the higher the risk”
Yet the study also found that a person’s combined risk of dying younger or developing cancer is lowest among light drinkers: those consuming only one to three alcoholic drinks per week. That risk increases with each additional drink consumed per week.
The study only showed associations between alcohol and such risks, and not any causal relationships.
Yet “others have indicated that light drinkers may be at a lower risk of cardiovascular disease for other reasons, as light drinkers tend to be wealthier and more health-conscious in other ways,” he said.
Those who never drink also might do so for other health reasons that could put them at an overall higher risk of death compared with light drinkers.
In general, a better understanding of the health risks that come with drinking alcohol can help inform clearer guidelines on how much you should limit your alcohol consumption, the researchers wrote in their study.
The difference in cancer, mortality risk
The adults completed a diet history questionnaire, which assessed their alcohol consumption. They also were followed up with during an average 8.9 years, and their cancer diagnoses were ascertained through medical records.
After analyzing the data, the researchers found that the average lifetime alcohol intake reported among the adults was 1.78 drinks per week, with men reporting that they drink more — 4.02 drinks per week — than women — 0.80 drinks per week.
In both the men and women, risk of death was lowest among those who consumed less than 0.5 drinks per day, the data showed. How much alcohol was consumed over a lifetime had a J-shaped relationship with overall mortality: Those who never drank had a slightly higher risk, and those who had more than 0.5 drinks per day had a much higher risk.
But the average amount of alcohol someone drank in a lifetime was linearly associated with total risk of cancer, in that risk went up the more someone drank, the data showed.
The study had some limitations, including that the data were limited to adults 55 and older, and the data on alcohol consumption were based on self-reported questionnaire responses, which tends to be the case for epidemiology studies of alcohol.
For instance, “alcohol increases risks for many cancers including, breast, colorectal, esophagus, liver, head and neck, and stomach,” said McTiernan, author of the book “Starved: A Nutrition Doctor’s Journey from Empty to Full.”
“Equally problematic was that they classified men and women the same in relation to categories of alcohol use. Women metabolize alcohol differently than men, so a ‘light’ drinker for men may be more of a ‘moderate’ drinker for women,” she said.
“The study strengths included the large sample size, including both women and men, and a lifetime history of alcohol use,” she said.
‘The more you drink, the higher the risk’
“It also reinforces the linear relationship between drinking alcohol and cancer risk: The more you drink, the higher the risk,” Brawley said.
“Alcohol is also estimated to be the third-largest contributor to overall cancer deaths in both men and women,” he added. “The evidence that alcohol increases the risk of cancer has existed for many years.”
The second was that the statement supported certain policy strategies for the first time, such as “raising taxes, limiting hours of sale, reducing youth exposure to alcohol marketing as a way of reducing high-risk drinking,” said LoConte, who was not involved in the new PLOS Medicine study.
As for that research, she said, “I think it reinforces what we already knew, which is moderate and heavy drinking is bad universally for cancer.”