Gastric Bypass Surgery Can Make Women Intolerant to Alcohol

By Sherry Baker @SherryNewsViews
December 07, 2015

After weight-loss surgery, women who drink two alcoholic drinks can feel like they downed four.

Almost 77 million U.S. adults are obese, according to the Centers for Disease Control and Prevention — and that raises their risk for heart disease, stroke, type 2 diabetes, and certain types of cancer. When diet and exercise don’t shed excess pounds, gastric bypass surgery may be an option. The procedure creates a stomach pouch too small to hold large amounts of food and bypasses parts of the small intestine so you absorb less food, resulting in weight loss.


RELATED TOPIC: How Successful Is Bariatric Surgery?


Gastric bypass surgery can benefit health but also may cause some well-known side effects, including nutritional deficiencies, food intolerance, and dumping syndrome. And now a study from Washington University School of Medicine in St. Louis has found another potential problem that can occur after the procedure. Women who’ve had gastric bypass surgery can get downright drunk — within only five minutes — after just one or two drinks. 

Although men weren’t included in this study, the researchers suspect men probably experience similar changes in how their bodies metabolize alcohol after gastric bypass. And even though it was a small study, the findings are worrisome enough that M. Yanina Pepino, PhD, who headed the research project, thinks people should keep a close eye on how much alcohol they consume after weight-loss surgery. 

“The findings tell us we need to warn patients who have gastric bypass surgery that they will experience changes in the way their bodies metabolize alcohol,” said Pepino, an assistant professor of medicine in Washington University’s division of geriatrics and nutritional science. “Consuming alcohol after surgery could put patients at risk for potentially serious problems, even if they consume only moderate amounts of alcohol.” 

The study participants included 17 obese women. Eight had undergone Roux-en-Y gastric bypass surgery (the most commonly performed weight-loss surgical procedure) one to five years earlier, while the other nine volunteers had not yet had surgery.

Each woman randomly drank either the equivalent of two alcoholic drinks or two nonalcoholic beverages over a course of 10 minutes. Then the researchers measured the women’s blood alcohol levels and used a survey to find out how drunk the women felt. About a week later, the same procedure was repeated — only this time, each woman was given the beverages they didn’t receive for the first test.

The results showed the women who had undergone gastric bypass surgery were legally drunk after only two alcoholic drinks. In fact, just five minutes after drinking booze, their blood alcohol levels averaged 1.10, significantly above the legal driving limit of 0.80. 

However, the blood levels of alcohol in women who had not undergone gastric bypass surgery didn’t peak until almost half an hour after they drank alcohol, measuring only 0.60. In addition, the women who had undergone gastric bypass felt impaired from alcohol far more quickly and for longer periods of time than women who had not had the surgery.

“These findings have important public safety and clinical implications,” said co-investigator Samuel Klein, MD, director of Washington University’s Center for Human Nutrition and the Center for Applied Research Studies. “After just two drinks, the blood alcohol content in the surgery group exceeded the legal driving limit for 30 minutes, but the levels in the other group never reached the legal limit. The peak blood-alcohol content in the surgery group also met the criteria that the National Institute on Alcohol Abuse and Alcoholism uses to define an episode of binge drinking, which is a risk factor for developing alcohol problems.”

Despite the possible complications and side effects of gastric bypass surgery, it can be lifesaving for those who are extremely overweight. A recent long-term study found 430 obese patients who had gastric bypass surgery to reduce their weight were half as likely to die over the next decade as a matched control group who didn’t have the surgery. 

The University of Virginia Healthcare System research team saw little difference in death rates for the first couple of years after gastric bypass, but 10 years later, even those with diabetes had significantly better survival rates than those who had not had the weight-loss procedure. The surgery can also help previously obese teens maintain health and weight-loss gains for at least three years.


March 31, 2020

Reviewed By:  

Christopher Nystuen, MD, MBA