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Harvard Reviews of Health News

Stomach Bypass May Boost Alcohol Abuse

The most common type of weight-loss (bariatric) surgery may increase people's risk of alcohol abuse, a new study finds. The study included almost 2,000 women and men who had weight-loss surgery. Before the surgery, they filled out questionnaires about their drinking habits. They also answered the questions 1 and 2 years after surgery. By 2 years after surgery, 11% of those who had gastric bypass surgery drank to excess. That was an increase of 50% from before the surgery. There was no increase among people who had gastric banding, another type of weight-loss surgery. About 5% drank to excess before and after surgery. Gastric bypass restricts the size of the stomach. This smaller stomach is attached directly to a lower part of the small intestine. The rest of the stomach and intestine are bypassed. Therefore, less food is absorbed. Researchers said this may change how the body breaks down alcohol. Banding uses a flexible band to shrink the size of the stomach. It does not bypass any of the intestine. The Journal of the American Medical Association published the study online. The Associated Press wrote about it June 18.

What Is the Doctor's Reaction?

Add another potential problem linked to gastric bypass — an increased risk of alcohol abuse. Gastric bypass is the most common weight-loss surgery.

The higher rate of excess or inappropriate use of alcohol did not show up until two years after surgery. Doctors call it alcohol use disorder. The results of the study were based on questionnaires. The Journal of the American Medical Association published the results online this week.

More people than ever are having weight-loss surgery. Doctors call it bariatric surgery. This year about 220,000 people in the United States will have it.

Weight-loss surgery (bariatric surgery) is very effective. Not only do people shed many pounds of fat, but they also decrease their risk of diabetes and heart disease.

In a gastric bypass (Roux-en-Y) procedure, the surgeon uses staples to create a small pouch in the stomach. This bypasses the rest of the stomach. The pouch is hooked to a loop of small intestine beyond the first section of intestine.

The smaller stomach pouch makes the person feel full after eating a small amount of food. Because the first section of the intestine is bypassed, fewer calories are absorbed.

Gastric bypass can be performed in either of two ways. In the open procedure, the surgeon makes a cut into the wall of the abdomen to reach the stomach and intestines.

Gastric bypass can also be performed with a laparoscope. There's no large surgical cut. Small holes are made in the abdomen. Cameras are used to guide the instruments. The technique is otherwise similar to the open procedure.

A less invasive weight-loss surgery is laparoscopic adjustable gastric banding. This is the simplest weight-loss procedure. It is done through small holes in the abdomen. The surgeon wraps an adjustable band around the upper stomach. This creates a small pouch with a narrow opening that empties into the rest of the stomach.

The risk of alcohol use disorder was twice as high for people who had gastric bypass than for those who had placement of an adjustable stomach band.

What Changes Can I Make Now?

The researchers could not give a definite reason for the increased risk of excess alcohol use after gastric bypass. But there are some possible explanations.

The stomach lining contains an enzyme that breaks down alcohol. The enzyme is called alcohol dehydrogenase. With a much smaller stomach, less of this enzyme is available.

We already know something about the effects of having less alcohol dehydrogenase available. That's because women have much less alcohol dehydrogenase in their stomach linings than men. As a result, they are more sensitive to alcohol than men. Very little alcohol is broken down in women's stomachs. Therefore, more is left to be absorbed into their blood. So one drink for a woman has about twice the effect as one drink for a man.

Alcohol remains at higher concentrations for longer periods of time in a woman's body than in a man's body. This exposes her brain and other organs to more alcohol. The same thing happens after gastric bypass. Alcohol hangs around a lot longer than before surgery.

Perhaps this is why excess alcohol use did not show up until the second year after surgery. During the first year after the operation, some casual drinkers might not have realized they were feeling twice as much effect from the same amount of alcohol they were used to drinking. So they may not have realized that they were developing alcohol dependence.

In fact, women who had gastric bypass did not have a significantly increased risk of alcohol use disorder. It's likely they were already used to drinking less. Men, especially young men, had a higher risk.

Perhaps the best advice for people having gastric bypass is to avoid alcohol completely for the first year. If that is not acceptable, limit alcohol use to one drink at a time. Drink no more than two to four times per week.

What Can I Expect Looking to the Future?

Potential candidates for gastric bypass who drink any amount of alcohol will now be warned of the risk of alcohol use disorder.

Author: Howard LeWine, M.D.
Date Last Reviewed: 6/19/2012
Date Last Modified: 6/19/2012