Mediterranean diet tied to lower risk of gallbladder surgery: study

Eating foods high in fiber, such as those found in a Mediterranean diet, was tied to a lower risk of gallbladder surgery in a recent French study.

Compared to people who didn't follow a Mediterranean diet pattern, those who adhered to it most closely had a significantly lower likelihood of needing a cholecystectomy, which is the medical term for an operation to remove the gallbladder, say the authors.

"We found that higher intakes of legumes, fruit, vegetable oil, and (whole grain) bread were associated with decreased cholecystectomy risk, and a higher intake of ham was associated with higher risk of cholecystectomy," wrote the authors in the American Journal of Gastroenterology.

About 700,000 cholecystectomies are performed every year in the United States, according to the American College of Surgeons. Most are the result of blockage due to gallstones.

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"Gallstones are very common, but most of them are asymptomatic, meaning people have no symptoms. If you don't have any symptoms from your gallstones, there's no reason to have your gallbladder removed," said Dr. James Lewis, a gastroenterologist at the University of Pennsylvania in Philadelphia who was not part of the study.

The vast majority of people with gallstones never have problems from them, Lewis said in a phone interview.

"When they do cause problems, then having your gallbladder removed is completely appropriate," he said.

64,000 women surveyed

The new study, led by Dr. Amelie Barre at the University of Paris Sud in Orsay, used information on nearly 64,000 women who were born between 1925 and 1950 and covered by a national insurance plan. Every two years, they answered questions about their health status, medical history, and lifestyle.

Over the course of 18 years, 2,778 of the women had their gallbladder removed.

Women who ate the most legumes, fruits, vegetable oil, and whole grain bread were anywhere from 13 to 27 per cent less likely to have gallbladder surgery than were women who ate the least of those foods.

A western dietary pattern — including high consumption of processed meat, canned fish, eggs, rice, pasta, appetizers, pizza, potatoes, cakes, and alcohol — was not linked with either a higher or lower risk for the surgery. There was, however, an association of ham intake with cholecystectomy risk.

But when researchers assigned a Mediterranean diet score to all participants, they found that women with the highest scores were 11 per cent less likely to have the surgery compared to women with the lowest scores.

If people really want to think about what they should be eating in order to increase their longevity ... they should try and follow a Mediterranean-style diet.- Dr. James Lewis, gastroenterologist 

This type of observational study can't prove that a Mediterranean diet was the reason for women's lower risk of gallbladder surgery, or that ham intake caused a higher risk. Furthermore, dietary intakes were self-reported at just one point in time. The reports may not have been accurate, and women's diets may have changed over time.

Still, Lewis said, the Mediterranean-style diet has consistently been shown to be associated with living longer.

"If people really want to think about what they should be eating in order to increase their longevity, it's very easy for me to recommend to them that they should try and follow a Mediterranean-style diet," he said.

In fact, the U.S. Department of Agriculture recently advised Americans to follow a diet that is very similar to a Mediterranean-style diet, Lewis noted.

"This is just one of many reasons that we should be following that style diet. If you look at the published literature on dietary patterns, what you'll see is that Mediterranean-style diet has been associated with a reduced overall mortality but also reduced cardiovascular mortality (and) reduced risks of cancer," he said.