A drink a day won’t keep the cancer away. New research shows even light amounts of alcohol consumption might raise people’s risk of several cancers.
Scientists at the University of Washington in Seattle examined the medical literature on alcohol and cancer. They found convincing evidence that any amount of regular drinking is linked to a higher chance of breast, colorectal, and other cancers. At the same time, the clearest dangers of alcohol, for cancer or other health conditions, came from heavy drinking.
“While potential health impacts at low-to-moderate levels varied by outcome, high levels of alcohol consumption were associated with increased risk across all outcomes,” the researchers wrote in their paper, published Monday in Nature Health.
No threshold of safety for cancer
The relationship between alcohol and our health can be complicated. Though studies have often linked health problems like cancer to even moderate alcohol consumption, for instance, others have suggested light drinking might actually help protect the heart.
To get a better sense of the big picture, researchers at the Institute for Health Metrics and Evaluation (IHME), an independently run research program based at the University of Washington, carried out a sweeping analysis of the data. They conducted 16 systematic reviews across four databases, which collectively included 843 cohort and case–control studies, and looked at how alcohol might affect 20 different health outcomes.
Alcohol was linked to a higher risk of all 10 cancers the researchers evaluated. And even at light levels of consumption—less than one drink a day on average—they still found a link between alcohol and a greater chance of breast, liver, colorectal, and prostate cancers, as well as cancers of the esophagus and pharynx.
“For cancer, the evidence is consistent and unambiguous: risk rises with any level of alcohol intake,” said senior author Emmanuela Gakidou, a professor in the department of Health Metrics Sciences at IHME, in a statement from the institute.
The complexity of alcohol risk
Things weren’t so simple with other health outcomes, though.
With conditions like Alzheimer’s disease and type 2 diabetes, for instance, the researchers found a small decreased risk associated with light alcohol consumption. With cardiovascular problems like heart disease, ischemic stroke, and hemorrhagic stroke, there was some evidence of a lower risk from light drinking as well, though it was more inconsistent.
As complex as the risks of drinking might be for some conditions, it’s still clear that the more we drink, the more we risk our health, the researchers say. And they hope their findings can inform future public health recommendations and policies. They found no strong evidence to support the current different standards of light drinking for men and women, for instance. And other research has shown that people are generally unaware of the link between alcohol and cancer.
“Importantly, our findings should not be interpreted as endorsing alcohol consumption for health benefits,” they wrote. “While low-to-moderate intake is modestly associated with lower risks of certain cardiovascular diseases, type 2 diabetes, and Alzheimer’s disease and other dementias, these associations are observational and uncertain, and must be considered alongside well-established harms for most outcomes, including increased cancer risks even at very low levels of consumption.”
