The editor of the Journal of the American Medical Association yesterday called on the United States and other "civilized" nations to outlaw boxing as "an obscenity," citing new evidence showing that 15 percent of all professional boxers suffer brain damage.

In an official statement issued at the same time, the AMA did not ask for a ban, but, in its strongest position ever on one of the nation's most popular sports, called for "strict medical supervision" of every boxing match, professional and amateur.

In his lead editorial in today's issue of the weekly journal, editor George D. Lundberg, a pathology professor who became AMA editor last January, said thousands of boxers wind up brain-injured, suffering from "dementia, memory loss, slurred speech, tremor and abnormal gait." Dr. Lundberg called boxing the only sport whose main aim is to injure and if possible knock out an opponent.

The official AMA position did not go as far. In the same issue, the group's Council on Scientific Affairs and a special boxing panel said efforts to ban boxing are not realistic. Boxing does not seem any more dangerous than other risky sports society accepts, the council said.

But the council called for giving a doctor the power to stop any bout any time, and keeping life-support systems at ringsides.

"No prudent physician," Lundberg said, "could have watched the most recent debacle/mismatch on Nov. 26 between Larry Holmes and Randall (Tex) Cobb and believe that the current boxing control system is functioning."

As columnist James J. Kilpatrick described that bout, "Larry Holmes devoted 14 rounds to making a pulp" of Cobb, and when Holmes let up in the 15th, "the disappointed fans began to boo and jeer," yelling " 'Get him.' " That came just nine days after boxer Duk Koo Kim was declared legally "brain dead," the result of his knockout by lightweight champion Ray (Boom Boom) Mancini.

The statement that 15 percent of fighters suffer brain damage is based on several studies. The AMA panel cited one showing that 17 percent of British fighters who boxed for six to nine years became brain damaged, with a third out-and-out "punch drunk": unsteady in speech and walk and vague in memory and grasp of reality.

A study of 14 Finnish boxing champions found that four of six pros and one of eight amateurs had X-ray evidence of brain injury. Ten of the 14 had what were described as "suspicious" brain waves, indicating possible brain damage.

A new Ohio study of 40 ex-boxers found that brain injuries were more related to the number of bouts fought than the number of knockouts.

Another editorialist in today's AMA Journal, Dr. Maurice Van Allen of the University of Iowa, blames society's toleration of boxing injuries on some dangerous folklore.

This is the idea, common in television dramas and films and comics, that blows to the head are trivial or funny. When fighters or football players are stunned or senseless, Van Allen said, sports announcers engage in a "prattle" of euphemisms like "shaken up," instead of saying there might always be a brain injury.

In some states, the AMA Scientific Council said, there is good medical supervision, but much professional boxing is poorly controlled. It called for:

A computerized national registry to record all bouts and injuries to help boxing commissions check fighters' fitness.

Frequent medical training for all ring personnel.

Upgrading and standardizing medical evaluations of boxers and sparring partners, with rules for regular examinations and for halting fights.

Some people, said editor Lundberg, argue that boxing allows disadvantaged or minority individuals to rise to wealth and fame. True, he said, but "the price . . . includes chronic brain damage for them and thousands of others who do not achieve wealth, fame or even a decent living."