It's well known that long-term alcohol consumption can be detrimental to your health, but does drinking too much booze increase your cancer risk? Researchers and cancer specialists believe alcohol consumption may be linked to certain types of cancer, including head and neck, liver, esophageal, colorectal, pancreatic, and breast, says Elizabeth Henry, MD, assistant professor of oncology at Loyola University Chicago’s Stritch School of Medicine. But it is important to stress that the risk from alcohol is cumulative and occurs over years, not from an occasional drink," she explains.
Alcohol may cause cancer in several ways. It can increase the effects of other cancer-causing substances, or damage cells, which may lead to cancer. Alcohol consumption also weakens your immune system by diminishing important nutrients in the body. Additionally, drinking too much can cause serious weight gain. The American Cancer Society estimate that excess weight may account for 20 percent of cancer deaths in women and 14 percent of men living in the United States.
Cancers Linked to Drinking
Head and neck cancer. Many doctors make a strong case that drinking too much can increase your risk for mouth, throat, and voice box cancer. "In head and neck cancer, it is the combination of smoking and drinking that is the biggest risk," says Dale Shepard, MD, PhD, an oncologist at the Cleveland Clinic. "Alcohol may act as a solvent and let the cancer-causing chemicals from tobacco smoke penetrate into cells."
Liver cancer. "Alcohol is directly toxic to liver cells and causes inflammation and scarring," notes Dr. Henry. "Scarring of the liver, called cirrhosis, leads to cancer. Your risk may be higher if you already have an underlying liver disease."
Esophageal and colorectal cancer. When you consume alcohol it's converted into a chemical called acetaldehyde in the digestive system, and acetaldehyde has been shown to cause cancer in lab animals. "People of Asian descent, who lack the enzymes to break down acetaldehyde, may be especially at risk for esophageal cancer," Henry says.
Breast Cancer. In a recent study, researchers followed 88,000 women for over a decade. Among the women, 2,944 developed invasive breast cancer, and women who reported having just one alcoholic drink per day doubled their risk for estrogen-sensitive breast cancer. Henry explains that "alcohol is known to increase circulating estrogen levels, so for estrogen-sensitive breast cancers, it could be a risk factor." She notes women who have four or more drinks a day face the highest risk, but more research is needed to fully assess the correlation.
Lowering Your Alcohol-Cancer Risk
Moderate drinking — defined as one drink per day for women and two drinks for men — has been linked to a reduced risk for heart disease, adding to the importance of weighing the possible risks and benefits of drinking. Until there's more information, the American Cancer Society, as well as both Henry and Shepard, say moderate drinking is safe for most people.
"If you have a family history of breast cancer or you have been diagnosed with breast cancer in the past, you need to take that into consideration when weighing risks and benefits of moderated drinking," says Henry. Discuss your alcohol risk with your doctor, especially if you were diagnosed with a cancer that has been linked to alcohol. "If you are being treated for cancer, drinking may make side effects of radiation therapy worse and may interfere with some cancer drugs. Ask your doctor if drinking is safe for you during treatment." However, she says, if you have been treated for cancer in the past, there is no evidence that alcohol use will increase the chances of your cancer returning.