PHILADELPHIA (AP) _ A Mediterranean diet rich in vegetable oil, nuts and fish may help fend off more than heart disease and diabetes: It appears to prevent gallstones, too.
Men who ate more of the unsaturated fats found in such foods lowered their risk of gallstones by nearly one-fifth, according to a 14-year study published in Tuesday's Annals of Internal Medicine.
Gallstones affect up to one in four Americans at some time in their lives. In some cases, the stones can cause abdominal pain and vomiting, and the gall bladder has to be removed.
Other research has suggested that diets high in saturated fat and refined carbohydrates increase the risk of gallstones, said Dr. Edward L. Giovannucci, a co-author and an associate professor at Harvard Medical School.
``It's probably not entirely an accident that some of the same mechanisms that relate to gallstones relate to having diabetes, or heart disease,'' he said. ``The same diet that is good for some of the Western diseases is good for gallstones.''
The study tracked the eating habits and medical histories of 45,756 men _ dentists, veterinarians, optometrists, osteopaths and podiatrists _ from 1986 to 2000. Whether such a diet would also prevent gallstones in women is not clear.
The way gallstones form ``is not exactly same between men and women,'' said Dr. Chung-Jyi Tsai, associate professor of medicine at the University of Kentucky Medical Center in Lexington, Ky., the lead author of the study. ``The study in women is ongoing.''
Doctors in recent years have come to recognize the heart-healthy benefits of the so-called Mediterranean diet, which is rich in unsaturated fats from vegetable oils, nuts and fish such as salmon and tuna.
In the study, 2,323 of the participants reported new cases of gallstone disease during the 14 years. Those in the highest one-fifth of the group in unsaturated fat consumption had an 18 percent lower risk of gallstones than those in the lowest one-fifth. Those in the highest group ate about twice as much unsaturated fat as the lowest group.
In the United States, 639,000 people are hospitalized each year because of gallstones, according to the National Center for Health Statistics.
Dr. Keith D. Lillemoe, chairman of surgery at the Indiana University School of Medicine, noted that diet is not the only factor that contributes to gallstones. But he said he and many other researchers have long thought that fat consumption must play a role.
``So the results don't surprise me, that there was some correlation,'' he said.