June 14, 2007 -- Patients who have undergone gastric bypass surgery to lose weight already know they have to watch how much they eat after the operation to keep that weight off. Now, a new study suggests they better keep a close eye on their alcohol intake, too.
After the surgery, patients get tipsier faster and take longer to sober up, says study researcher John M. Morton, MD, MPH, the director of bariatric surgery at Stanford University School of Medicine.
"One drink could be enough to place them at risk for a DUI," Morton tells WebMD.
The new study supports what gastric bypass surgeons have long suspected, says Morton, who is presenting the findings this week at the 24th annual meeting of the American Society for Bariatric Surgery in San Diego.
What Triggered the Study?
"We anecdotally know that patients have an altered sense of alcohol [after the surgery]," Morton says. "It affects them quickly. My patients often say, 'I get tipsy more easily' or 'I'm a cheap date now.'"
In late 2006, the Oprah Winfrey show aired a segment titled "Suddenly Skinny," which discussed the reactions gastric bypass patients can have to alcohol, including some who began to binge drink, in effect trading a food addiction for an alcohol addiction. Morton says he got numerous calls from his concerned patients.
So Morton's team of researchers decided to see if science supports the anecdotal observations that gastric bypass patients can't hold their liquor as well as before.
The researchers compared the effects of drinking a 5-ounce glass of red wine on 19 gastric bypass patients (whose weight had stabilized after the surgery) and 17 people who had not had the surgery. The surgery patients' average age was 47; the average age of the nonsurgery group was 37. The average weight of the surgery group was 200 pounds; the average weight of the nonsurgery group was 149. The bypass patients had gone, on average, from a body mass index or BMI of 51 to 33 (still considered obese).
Everyone was instructed to drink the wine within 15 minutes, and then Morton's team measured the participants' breath alcohol levels every five minutes until the levels returned to zero. The researchers measured how long it took each person after finishing the drink to reach peak breath alcohol levels, which Morton says correlate with blood alcohol levels, and how long it took for the breath alcohol levels to return to zero.
All participants also reported any symptoms they had, such as euphoria, dizziness, or slurred speech.
The surgery patients had an average peak alcohol breath level of 0.08% -- enough to be declared drunk when driving a motor vehicle. The nonsurgery participants had a level of 0.05%.
The bypass patients took 108 minutes, on average, to normalize back to a zero breath level of alcohol; the breath levels of alcohol of the nonsurgery group returned to zero after 72 minutes.
Based on the levels and the time it took for them to normalize, the surgery patients should have had more or greater symptoms than the nonsurgery group. But surprisingly, "the symptoms were exactly the same," says Morton. The surgery patients' symptoms "should have been more pronounced because their peaks were higher and they took longer to normalize."
Interpretations of the Study
Based on the study findings, gastric bypass patients "are not metabolizing alcohol the same way and not feeling the same way [as the nonsurgery participants]," Morton tells WebMD.
The finding, he says, may explain why some experts have observed, and feared -- that those who undergo bypass surgery might experience "addiction transfer," in which they trade the addiction of binge eating, an issue for many gastric bypass surgery patients, for an alcohol addiction.
"This might account for some people becoming addicted to alcohol [after bypass surgery]," Morton tells WebMD. "They may have to drink more to get the same effect."
Physiologically, he says, there are explanations, too. The levels of a key enzyme for metabolizing alcohol, called alcohol dehydrogenase, decline because of the much smaller stomach size after gastric bypass surgery. Gastric bypass and other weight loss surgeries reduce the stomach's capacity to a few ounces. "This is probably why the alcohol peaks higher and stays higher," Morton says.
Why the patients aren't feeling more symptoms is not known, he adds.
"Alcohol is not calorie-free, of course," Morton reminds his patients. "A glass of wine has 125 calories. The other thing that happens when you drink alcohol is it relaxes you both outside and inside -- your esophagus and stomach also relax, and that allows you to eat more."
"I tell my patients to be careful with alcohol, and if they drink to do so at home or to have a designated driver," Morton says.
"This study supports our observations," says Philip Schauer, MD, president of the American Society for Bariatric Surgery and director of the Bariatric and Metabolic Institute at Cleveland Clinic. "Because we are reducing stomach capacity, food and liquor move rapidly into the intestines for absorption."
This study does not prove that alcohol problems are more likely among bariatric patients, says Neil Hutcher, MD, immediate past president of the society and director of bariatric surgery at Bonsecour St. Mary’s Hospital in Richmond, Va. "This study does not in any way address whether increased blood levels of alcohol or the magnitude of them has anything to do with alcohol addiction or the transference of food dependence to alcohol dependence,” he says.
More than 177,000 people in the U.S. had gastric bypass or other forms of bariatric or weight loss surgery in 2006, according to estimates from the Society. In consultations with his patients about what to expect after surgery, Schauer says, "I usually tell them, 'One beer will feel like two.'"