The bacchanalian appetites of ancient Rome caused a widespread incidence of gout among the aristocracy, including most of the emperors, and therein lies a strong clue, according to a Canadian researcher, that lead poisoning contributed to the fall of the Roman Empire.

Much of the food and wine the Romans consumed to such excess was contaminated with amounts of lead far exceeding today's safety standards. Accumulations of lead in the body can cause one form of gout, a painful and sometimes crippling inflammation of the joints, as well as the mental retardation and erratic behavior normally associated with lead poisoning.

Reviewing the personalities and habits of Roman emperors from 30 B.C. to 220 A.D., Dr. Jerome O. Nriagu, a Canadian scientist, found that two-thirds of them, including Claudius, Caligula and Nero, ''had a predilection to'' lead-tainted diets and suffered from gout and other symptoms of chronic lead poisoning. He reported his conclusions in the issue of The New England Journal of Medicine published today.

''The coexistence of widespread plumbism and gout during the Roman Empire seems to have been an important feature of the aristocratic life style that has not been previously recognized,'' Dr. Nriagu wrote. ''This provides strong support for the hypothesis that lead poisoning contributed to the decline of the Roman Empire.''