A study of 2,300 people who'd had various types of bariatric surgery showed a 41 percent drop in deaths overall, compared to those who didn't have surgery.
Heart-related problems like heart attacks, stroke, and kidney failure, fell 39 percent.
The study's lead author says the findings were surprising.
"To see a 39 percent reduction in all of the events and a 41 percent reduction in mortality, you know, there are very few therapies in treating heart disease that come close to having this big an effect," says Dr. Steven Nissen of the Cleveland Clinic.
He says the important element is significant sustained weight loss, no matter how it occurs.