Binge drinkers beware: that big hangover headed your way reveals only a fraction of the physical damage you will weather.
Fresh research shows that young, healthy adults who toss down four to five shots of alcohol in a 20-minute span dangerously muzzle their immune systems — a timely warning for New Year's Eve revelers who plan to party hard.
Evidence of a potentially hazardous drop in the body's infection-fighting, wound-healing power shows up in binge drinkers' blood steams just two hours after they downed their barrage of shots, according to researchers at the Loyola University Chicago Stritch School of Medicine.
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"When a lot of people think of harmful patterns of drinking, they think of people who are alcoholics or daily heavy drinkers," said the lead author, Dr. Majid Afshar, a pulmonologist, critical care physician and epidemiologist at Loyola.
"But the study makes the point that one episode of this type of drinking can certainly be disruptive in your immune system and potentially lead to problems," Afshar said.
Those problems? A higher risk of pneumonia and infection. In addition, people who sustain alcohol-involved injuries may experience slower healing of fractures plus poor responses to blood transfusions and resuscitations, past studies have shown.
And the immune system's post-binge deterioration — detected in a slew of cells critical to maintaining health and proper healing — "stayed persistent at five hours after peak intoxication," Afshar said.
Afshar led the study while at the University of Maryland, where he completed a fellowship below joining Loyola. The findings were published online in the journal Alcohol.
To get a closer look at the body's descent after swallowing a flurry of shots, Afshar and his team assembled 15 volunteers for a scientific bender.
The eight women and seven men, with a median age of 27, each gulped enough vodka-and-seltzer cocktails — generally four to five drinks each, containing one part vodka, four parts seltzer — to meet the definition of binge drinking. (A 1.5-ounce shot of vodka is the alcohol equivalent of a 5-ounce glass of wine or 12-ounce can of beer.)
Researchers took blood samples from the volunteers at 20 minutes, two hours and five hours. Intoxicated patients are known typically to arrive at trauma centers for treatment of alcohol-fueled injuries two to five hours after they reach peak intoxication.
In an unexpected twist, blood samples checked 20 minutes into the experiment showed the subjects' immune systems had actually geared up, with higher levels of three types of white blood cells: leukocytes, monocytes and natural killer cells. The researchers also noted increased amounts of proteins called cytokines that signal the immune system to work harder.
But "at two hours, we started to see an opposite effect," Afshar said.
By that hour, the volunteer's blood samples each showed fewer circulating monocytes and natural killer cells and higher levels of different types of cytokines that signal the immune system to become less active.
Researchers carefully selected their 15 study participants based on their ages to best reflect societal trends. One in six U.S. adults binge drinks roughly four times a month, and binge drinking is more common in young adults aged 18 to 34, according to the Centers for Disease Control and Prevention.
The study was funded by the National Institute on Alcohol Abuse and Alcoholism (NIAAA), and by the University of Maryland.
The findings offer a stark reminder that alcoholic overindulgence, even once, can carry bad consequences, said George Koob, director of the NIAAA, part of the National Institutes of Health.
"While it is well known that excessive alcohol use can lead to traumatic injury and the behavioral and physiological pathology associated with addiction," Koob said, "studies like this help us understand that even a single binge drinking episode can have detrimental effects on our immune system."
The NIAAA just published a holiday-themed consumer fact sheet about excessive drinking.
Their tips include: "Pace yourself. Know what constitutes a standard drink and have no more than one per hour."
And this: "Have 'drink spacers' — make every other drink a nonalcoholic one."