The American Medical Association Council on Medical Affairs lists the annual number of boxing deaths at 0.13 per 1,000 participants, not out of line with other high-risk sports such as motorcycle racing, parachuting or hang gliding.
Capanna (ringside Doctor at a Boxing match where a fighter Jimmy Garcia died) said there is danger in all sports, particularly football where players are coached to hit an opponent as hard as they can.
"Nothing is benign," he said. "One day last year I operated on two golf injuries in the same day. One had a subdural hematoma such as the one suffered by Jimmy Garcia from being hit with a golf ball and he later died. Another got hit in the forehead by his brother with a 9-iron."
I couldn't help but notice MMA was not included in that first paragraph.
Side Note: There has been 500 deaths as a result of Boxing from late 18 hundreds to the present!