Consuming alcohol — even in moderation — increases the risk of dying from cancer, according to a recent study. Researchers also stated that the link between alcohol and cancer development is often “underemphasized” by doctors.
The study, published in mid-February in the American Journal of Public Health, states that alcohol is responsible for approximately 20,000 cancer deaths each year in the U.S. — equivalent to about 3.5 percent of all U.S. cancer deaths, according to a news release from the Boston University Medical Center.
Researchers from that medical center, the National Cancer Institute, the Alcohol Research Group, and others reported the findings after examining recent data on alcohol consumption and cancer mortality.
Breast cancer was the most common cause of alcohol-related cancer deaths in women, accounting for about 6,000 deaths annually, according to the study. Cancers of the mouth, throat and esophagus were common causes of alcohol-related cancer deaths in men, resulting in a total of about 6,000 annual deaths, according to the news release.
Researchers also found that alcohol-related cancer deaths accounted for an average of 18 years of potential life lost.
While heavy alcohol use led to a higher cancer risk, the study found that an average consumption of 1.5 drinks per day or fewer accounted for 30 percent of all alcohol-related cancer deaths.
David Nelson, the lead author of the study, said he was not surprised by the findings, because alcohol is known to be a carcinogen that causes cancer.
“There is no minimum or safe level when it comes to cancer and alcohol use,” Nelson said in a phone interview with the Napa Valley Register.
Exactly why alcohol increases cancer risk is not fully understood. One theory is that DNA becomes damaged as alcohol is broken down in the body. Indirectly, alcohol may also raise estrogen levels, increase body weight, or contribute to deficiencies in folate, which may lead to an increased risk of breast or gastrointestinal cancers, said Dr. Ethan Schram, of St. Helena Hospital’s Martin-O’Neil Cancer Center.
While the cancer risk associated with drinking alcohol is “in plain sight,” Nelson said the general public seems mostly unaware of it. He said scientific researchers haven’t done enough to get the message out.
Dr. Doug Wilson, a Napa physician who specializes in family medicine, said the study should be taken into careful consideration by moderate drinkers — especially women.
“Women should ask themselves if the pleasure they’re getting from (drinking) is worth the risk,” he said.
Wilson added that it’s never too late to start making healthier choices.
“Any decrease in (alcohol) consumption is a decrease in risk,” he said.
When contacted by the Napa Valley Register, the Napa Valley Vintners trade association declined comment, stating that its officials do not have medical expertise and do not typically comment on these kinds of studies.
Dr. Arthur Klatsky, an adjunct investigator at the Kaiser Permanente Northern California Division of Research, questioned some of the study’s findings.
Heavy drinking is known to increase the risk of developing certain cancers, such as those of the mouth, liver, breast, colon and rectum, Klatsky said. Light or moderate drinking “slightly” increases the risk of breast cancer, but its effect on other forms of cancer is “not as clear-cut,” Klatsky said.
For men and women over the age of 50, Klatsky said the benefits of moderate amounts of alcohol generally outweigh the risks. But advice needs to be “individualized,” he said.
“One size does not fit all,” Klatsky said.
An older man at risk for cardiovascular disease, for example, would benefit from moderate drinking, Klatsky said. But a young woman with little risk of cardiovascular disease should limit or avoid alcohol to lower her odds of developing breast cancer.
Schram, of the Martin-O’Neil Cancer Center, agreed that the results of the study should be kept “in perspective.”
“Alcohol is socially and culturally an important part of life here in Napa Valley and many places in the country,” he said. “The risk of being in a fatal accident on the road is five times higher than the risk of cancer death in moderate drinkers.”
While the fear of developing cancer may motivate some people to quit or cut back, Schram said the risk is not high enough for most moderate drinkers to change their alcohol intake.
“It’s important to keep in mind ... that the vast majority of moderate drinkers do not develop cancer and never will,” Schram said. “I personally tell my patients that they can do most anything in moderation — except smoking.”