Basil Rifkind, 73, a physician who was a national leader in the 1980s effort to persuade Americans to lower their cholesterol level and avoid heart disease, died June 22 at Sibley Memorial Hospital in Washington. He had Parkinson’s disease.

Rifkind was one of the principal figures on a 1984 landmark study that provided the first conclusive evidence that lowering blood cholesterol can prevent heart attacks.

The 10-year study of 3,806 middle-aged men with elevated cholesterol and no history of heart disease showed that those who added a cholesterol-lowering drug to a low-fat diet had 24 percent fewer fatal heart attacks and 19 percent fewer nonfatal heart attacks than the diet-only group.

The importance of this finding confirmed what researchers and physicians long suspected, prompting a major public education project.

“The majority of people don’t know that they are a time bomb,” Rifkind told The Washington Post in 1985.

Such pithy quotes made Rifkind, chief of the fat metabolism branch at the National Heart, Lung and Blood Institute, a part of the National Institutes of Health, a favorite source for reporters.

When others later criticized the scientific establishment for confusing the public about the connection between fats, cholesterol and heart disease, Rifkind disarmingly agreed.

“It’s really difficult for the public. But this is the way scientific research moves along. It is disquieting and confusing,” he said.