The study is published online in the journal Alcoholism: Clinical & Experimental Research.
Increased Mortality Risk
"It used to seem like having one or two drinks per day was no big deal, and there even have been some studies suggesting it can improve health," said first author Sarah M. Hartz, MD, Ph.D., an assistant professor of psychiatry. "But now we know that even the lightest daily drinkers have an increased mortality risk."
Although some earlier studies have linked light drinking to improvements in cardiovascular health, Hartz said the new study shows that those potential gains are outweighed by other risks. Her team evaluated heart disease risk and cancer risk and found that although in some cases, drinking alcohol may reduce the risk of heart-related problems, daily drinking increased cancer risk and, as a result, mortality risk.
"Consuming one or two drinks about four days per week seemed to protect against cardiovascular disease, but drinking every day eliminated those benefits," she said. "With regard to cancer risk, any drinking at all was detrimental."
Safest Level of Drinking: None
The new study comes on the heels of research published in The Lancet, which reviewed data from more than 700 studies around the world and concluded that the safest level of drinking is none. But that study looked at all types of drinking-- from light alcohol consumption to binge drinking. The Washington University team analysis focused on light drinkers: those who consumed only one or two drinks a day.
The Washington University study focused on two large groups of people in the United States: 340,668 participants, ages 18-85, in the National Health Interview Survey, and another 93,653 individuals, ages 40-60 who were treated as outpatients at Veterans Administration clinics.
"A 20 percent increase in the risk of death is a much bigger deal in older people who already are at higher risk," Hartz explained. "Relatively few people die in their 20s, so a 20 percent increase in mortality is small but still significant. As people age, their risk of death from any cause also increases, so a 20 percent risk increase at age 75 translates into many more deaths than it does at age 25."
The Risk Is Cancer
She predicted that as medicine becomes more personalized, some doctors may recommend that people with family histories of heart problems have a drink from time to time, but in families with a history of cancer, physicians may recommend abstinence.
"If you tailor medical recommendations to an individual person, there may be situations under which you would think that occasional drinking potentially could be helpful," she said. "But overall, I do think people should no longer consider a glass of wine a day to somehow be healthy."