March 14, 2011 -- Having three or more drinks of liquor a day is associated with an increased risk of dying from pancreatic cancer, a new study shows.
That’s significant, experts say, because only two other lifestyle factors that are modifiable -- smoking and obesity -- have been shown to be associated with the risk for pancreatic cancer, which is one of the leading causes of cancer death.
“Those are really the only two modifiable risk factors we have for this very fatal cancer,” says study researcher Susan M. Gapstur, PhD, MPH, vice president of the epidemiology research program at the American Cancer Society.
“So finding a link between heavy alcohol intake and pancreatic cancer death is important because it potentially adds to the list of modifiable risk factors,” she says.
Other experts said the study was well done, but limited by design.
“It’s provocative,” says David Kooby, MD, a surgical oncologist specializing in pancreatic cancer at Emory University in Atlanta.
“I don’t think it is earth shattering because in the back of our minds we know alcohol upsets the pancreas,” says Kooby, who reviewed the study for WebMD but was not involved in the research.
“This is an observational study, so they can’t prove that alcohol causes pancreatic cancer, only that the two things are associated,” Kooby says. “But for some questions, it’s the best you can do.”
According to the National Cancer Institute, pancreatic cancer is the fourth deadliest cancer in men and the third deadliest in women.
Alcohol and Pancreatic Cancer
The study, which included more than 1.2 million Americans who were followed for 24 years, found that overall those who reported drinking three or more liquor drinks daily saw their risk of dying of pancreatic cancer go up by about one-third compared to nondrinkers.
The same increase in risk wasn’t seen in people who reported drinking the same amount of beer or wine each day. Researchers think that may have something to do with the way these different beverages are packaged and consumed.
Beer, for example, is most often found in single-serving bottles or cans, which helps keep alcohol consumption in check. When it comes to liquor, though, Gapstur says, “People are pouring a little more from the bottle.”
“For any given liquor beverage the average amount of alcohol consumed is probably, on average, higher than an average drink of wine or beer,” Gapstur says.
But other experts think the lack of an association between pancreatic cancer and beer or wine may be a statistical blip. They caution people not to assume those drinks are safer than liquor.
“The person who is drinking 10 beers a day shouldn’t say, ‘Oh, I’m fine,’” says Kooby. “The message of this study is moderation, not that too much beer or wine is OK.”
The pancreatic cancer-alcohol associations remained after researchers tried to adjust the numbers for the effects of other things known to influence cancer risk, like obesity, age, and a history of smoking, or diabetes.
How Alcohol May Harm the Pancreas
Alcohol is partially metabolized in the pancreas, Gapstur says, “and some of the early metabolites of alcohol can be toxic to the cells. They can lead to changes in pathways that are important to cancer like inflammation.”
It’s long been known that heavy drinking can damages the pancreas and that excessive alcohol consumption can contribute to pancreatitis, an inflammation of the pancreas characterized by severe abdominal pain and vomiting.
Chronic pancreatitis, in turn, has been linked to a higher risk of pancreatic cancer.
What’s been harder for scientists to prove, however, was that alcohol increased the risk of pancreatic cancer, Gapstur says, largely because most studies have been too small to detect an association.
“People who drink are also more likely to smoke cigarettes, and smoking is a risk factor for pancreatic cancer,” Gapstur explains.
Safe Drinking Limits
Moderate drinking, at least in middle-aged adults, has been tied to a lower risk of cardiovascular disease.
So where is it safe to draw the line?
According to Gapstur, the best rule of thumb is to follow the recommendations of the American Cancer Society to “limit consumption to no more than one drink a day if you’re a woman and no more than two drinks a day if you’re a man.”