Alcohol Consumption and Cancer: What You Need to Know

“I’ll drink to that!” is commonly heard at convivial gatherings, but research suggests that iced tea or coffee is a better toasting option. Before you refill your glass, consider this: after extensive reviews of research studies, scientists agree: there’s a strong connection between alcohol consumption and several types of cancer.

According to the National Cancer Institute, the research evidence shows that the more alcohol you drink—particularly the more alcohol you drink regularly over time—the higher your risk of developing an alcohol-associated cancer.

How much is too much?

The federal government’s Dietary Guidelines for Americans 2010 defines moderate alcohol drinking as up to one drink per day for women and up to two drinks per day for men. Heavy drinking is defined as having more than three drinks per day or more than seven drinks per week for women and more than four drinks per day or more than 14 drinks per week for men.

The cancer connection

Drinking is closely related to the following types of cancer:

  • Head and neck cancer: People who have 3.5 or more drinks per day are two to three times more likely than nondrinkers to develop head and neck cancers, especially cancers of the mouth, throat, and voice box. If you consume that much alcohol and also use tobacco products, your risk increases.
  • Esophageal cancer: Drinking is also a major risk factor for esophageal squamous cell carcinoma. The risk increases in people who inherit a deficiency in an enzyme that metabolizes alcohol.
  • Liver cancer: Alcohol consumption is an independent risk factor for and a primary cause of liver cancer.
  • Breast cancer: More than 100 studies consistently found an increased risk of breast cancer linked to increased drinking. Scientists have shown that alcohol can increase blood levels of estrogen, a sex hormone linked to the risk of breast cancer. In fact, the studies showed that women who drank more than three drinks a day had 1.5 times the risk of developing breast cancer as nondrinkers. The risk of breast cancer was higher across all levels of alcohol intake, even less than one drink a day. This risk may be higher in women who do not get enough folate (B vitamin) from food or supplements.
  • Colorectal cancer: People who regularly drank 3.5 drinks a day had 1.5 times the risk of developing cancers of the colon and rectum than nondrinkers or occasional drinkers.

Dr. Gilberto de Lima Lopes Jr., an oncologist with the Sylvester Comprehensive Cancer Center, part of the University of Miami Health System and the Miller School of Medicine explains how alcohol increases cancer risk:

“One way we think alcohol causes cancer is that our bodies break it down into acetaldehyde, a toxic chemical and human carcinogen. Acetaldehyde can damage both DNA (the genetic material that makes up genes) and proteins. Moreover, ethanol (the primary part of alcoholic beverages) is also toxic. Alcohol may also impair our body’s ability to break down and absorb nutrients that may help lower your risk of cancer, including vitamin A; nutrients in the vitamin B complex, such as folate; vitamins C, D, and E; and carotenoids.”

If you’re wondering if the much touted resveratrol in red wine reduces cancer risk, research has not yet shown it to be effective. Eating healthy, regular exercise, stress management, and avoiding tobacco products may decrease the risk of cancer and thus reduce the risk brought on by alcohol. Ultimately, however, “There is no safe level for consumption as the risk of cancer increases even with one drink a day,” Dr. Lopes says.

At this point, it seems that teetotaling may be your healthiest option.