Nicotine chewing gum? Medically endorsed snuff?

These new and ancient forms of nicotine are being advocated, surprisingly, to help smokers kick the harmful cigarette habit.

Nicotine chewing gum is being used in Canada, Great Britain and Switzerland and is about to get a U.S. test.

The idea is to give persons heavily addicted to nicotine a less harmful substitute that may help them desert the habit, says a scientist at the National Institute on Drug Abuse, federal sponsor of the U.S. test.

An article in Lancet, a respected British medical journal, says switching from cigarettes to snuff-sniffing "could have enormous health benefits."

It could "save more lives . . . than any other preventive measure likely [in] developed nations well into the 21st century," say scientists at the Addiction Research Unit of the London Institute of Psychiatry, and at New Cross Hospital.

Both snuff and chewing tobacco are already being used by some nicotine addicts as cigarette substitutes.

Neither has been linked to U.S. cancer deaths by any firm statistics. But tobacco chewing has been associated with oral cancer and other oral disease in Asia. Evidently putting any tobacco in the mouth can lead to mouth diseases, including some cancers.

Many American snuff users put it in their mouths instead of sniffing it. And snuff is used in this country by 2.5 men in 100 and a surprising one woman in 200, the government says.

Even sniffing snuff can lead to medical problems, its British advocates concede. But "the campaign to end cigarette smoking is proving slow and tedious," the snuff delivers none of smoking's harmful combustion products, they argue.

A Swedish company makes the most widely used nicotine gum Nicorette. Dow Chemical Co. markets it in Canada where it is available by prescription and is negotiating for a U.S. license.

American use requires Food and Drug Administration approval. In Canada, said Dr. William Nummy, Dow director of drug research and development, approval was given quickly, and sales have grown faster than "any product has come on for us in Canada for a long time."

The gum has a spicy, cinnamon flavor. But British and Canadian doctors point out that it is not innocuous, and, especially at the start or if overused, can cause hiccups, nausea, sore throat or mouth sores. It might also be hazardous to users with heart disease.

Dr. Gio Gori of the National Cancer Institute thinks "more substantial evidence" is needed that the newest gum works, in view of disappointing tests of some past forms. He also says "nicotine's acute toxicity is fearsome," and placing several sticks at once in one's mouth could prove fatal. f

Still, said Dr. Chris-Ellyn Johanson, research psychologist at the National Institute on Drug Abuse here, the gum has "a lot of possibilities" in helping "wean addicts off nicotine" and "helping them learn to live without a cigarette in their hands."

NIDA is financing a test of the latest version of the gum at the University of California at Los Angeles.

As to snuff, he says, "I'm not aware of any major studies of its safety. I don't know if it's good or bad."

'Smokers who quit have to relearn almost everything they do," says Dr. Nina Schneider at UCLA. "It's almost like losing a mate," so the gum just might help.