While moderate alcohol intake is consistently associated with a decrease in the risk of cardiovascular disease, the verdict is less clear when it comes to alcohol and cancer risk. Some evidence strongly indicates drinking may increase the risk of certain types of cancer, but other studies suggest it doesn’t adversely impact cancer survival rates. Dr. Polly Newcomb, head of the Cancer Prevention Program at Fred Hutchinson Cancer Research Center, serves up some advice.
Photo by Robert Hood / Fred Hutch
How common is drinking in the U.S.?
Nearly half of adults in the U.S. report being light or moderate drinkers, defined as one drink a day for women, two drinks a day for men. Heavy drinking is anything over that amount, and about 7 percent of U.S. adults fit into this category. About 3 percent of U.S. cancer deaths each year can be attributed to alcohol consumption.
What types of cancer are clearly associated with drinking?
Regular, heavy drinking is associated with an increased risk of oral, throat, larynx, esophagus, liver, breast, colon and rectal cancers. We also know the risk rises with the amount of alcohol consumed.
Should people who are considered at high risk for cancer due to family history be concerned about drinking?
Some studies have found that reducing alcohol consumption may decrease cancer risk among people with a family history of the disease. People with known genetic risk factors should consult their doctor about their alcohol intake.
Is there such a thing as a safe amount of alcohol for people concerned about reducing their cancer risk?
When it comes to drinking and cancer risk, moderation is the key.
Do all types of alcohol pose the same cancer risk?
In general, it’s not the type of alcohol a person drinks but the amount that impacts cancer risk.
What about wine? Is red better than white?
Red wine contains certain compounds, such as resveratrol, which, research suggests, have some anticancer properties. However, my research group found when it comes to increasing breast cancer risk, it makes no difference — red and white wines are equal offenders.
How does alcohol increase the risk of cancer?
In a variety of ways. It increases levels of circulating estrogen, a hormone linked to breast cancer. It also may interfere with the absorption of nutrients such as folate that may protect against cancer. When the body metabolizes the ethanol in alcoholic drinks, it converts it to a toxic chemical called acetaldehyde, a potential carcinogen that has been shown to damage genes and proteins. In addition, the process of fermenting and producing alcohol can introduce various carcinogens into the mix. Heavy drinking also can cause cirrhosis of the liver, which is a risk factor for liver cancer.
How might genetics factor into the alcohol and cancer-risk equation?
Research shows that genes play a role in the metabolism of alcohol, which can influence cancer susceptibility. For example, many people of Asian descent carry a genetic variant that speeds up the conversion of ethanol to toxic acetaldehyde, which can increase the risk of some cancers.
Does tobacco use magnify the cancer-causing effects of alcohol?
Studies indicate that people who both drink and use tobacco are at a significantly higher risk of cancers of the head, neck and esophagus than those who use either substance alone. However, there is little evidence that alcohol further increases the very strong association between smoking and lung cancer.
Any other advice?
Don’t smoke. Maintain a healthy weight. Exercise regularly. Eat a healthy diet. Use sunscreen. Talk to your doctor about cancer screening and getting vaccinated for certain infection-related cancers.
Dr. Polly Newcomb is a member of the Public Health Sciences Division at Fred Hutch. She serves as editor of the American Journal of Epidemiology and is president-elect of the American Society of Preventive Oncology. She is also a 2014 Fulbright Scholar.
Kristen Woodward, a science editor at Fred Hutchinson Cancer Research Center, has been in communications and media relations at Fred Hutch for more than 15 years. Before that, she was a managing editor at the University of Michigan Health System and a reporter/editor at The Holland Sentinel, a daily in western Michigan. She has received many national awards for health and science writing. She received her B.A. in journalism from Michigan State University. Reach her at email@example.com.