Ronald Davis, 52, leading health advocate

RONALD M. DAVIS (ap file/2006)

NEW YORK - Ronald M. Davis, a former president of the American Medical Association who campaigned against tobacco, alcohol, obesity, illicit drugs, and unhealthy lifestyles in his career as a public health official, died Thursday at his home in East Lansing, Mich. He was 52.

The cause was pancreatic cancer, said Brenda Craine, a spokeswoman for the medical association. Dr. Davis received the diagnosis in February and had since helped to raise public awareness of the disease, which afflicts 37,000 Americans a year and kills 34,000.

In 1988, when US surgeon general C. Everett Koop released the most devastating of his reports on smoking - calling it as addictive as heroin and saying it was responsible for 300,000 American deaths annually - Dr. Davis was a young crusader in the antismoking wars, a rising official at the Centers for Disease Control and Prevention. Despite years of warnings on cigarette packs, millions of people were still lighting up, and American cigarette exports were earning $2.5 billion a year and rising relentlessly.

To Dr. Davis, the struggle seemed hopeless. "I don't know how to deal with it," he said. "My life's work has been devoted to reducing global morbidity figures, yet in this case we are exporting an obviously hazardous agent. This kind of thing perplexes me as a government official and frustrates me as a doctor."

In the generation since, millions have given up smoking, though 400,000 still die from the habit every year. But colleagues said Dr. Davis stayed in the Sisyphean fight against smoking and other health hazards in a nation of fast foods, caloric binges, lazy ways, and the anodynes of liquor and cocaine.

With speeches and lectures, articles in peer journals and on websites, surveys and health bulletins, and legal depositions and testimony before congressional committees and state and federal agencies, Dr. Davis was a tenacious campaigner for healthy lifestyles, promoting exercise, better diets, and an awareness of the corrosive effects of tobacco, alcohol, and illegal drugs.

Dr. Davis, a specialist in preventive medicine, served as president of the medical association from June 2007 to June 2008, after decades as a public health official. He was the director of the Office on Smoking and Health at the CDC from 1987 to 1991, the chief medical officer of the Michigan Department of Public Health from 1991 to 1995, and since then the director of health promotion and disease prevention for the Henry Ford Health System in Detroit.

He also delivered the medical association's historic recent apology to black physicians for more than a century of exclusion from membership. While the AMA, founded in 1847, had no formal policy barring black doctors, it required members until the 1960s to belong to state or local medical societies, many of which barred blacks.

"This is the moment we can stand as one," Dr. Davis told the National Medical Association, America's largest black doctors' organization, in July.

Ronald Mark Davis was born in Chicago to George and Alice Komessar Davis. He received a bachelor's degree in zoology from the University of Michigan in 1978, and at the University of Chicago he earned a master's in public policy in 1981 and his medical degree in 1983.

After an internship in Chicago, he trained in epidemiology and became a resident in preventive medicine at the Centers for Disease Control in Atlanta. In 1984, he became the first resident ever named to the AMA's board, serving until 1987. He was elected to the board again in 2001 and was reelected in 2005.

He taught at Johns Hopkins, Wayne State, Morehouse, Michigan State, and the universities of Illinois and Michigan. He directed many studies and testified in tobacco cases and before government agencies on many topics, including obesity.

At his retirement luncheon in Chicago in June, he cited some of the villains: pizzas, hamburgers, and in Detroit the traditional paczki - a deep-fried Polish pastry that resembles a jelly doughnut. The winner of a paczki-eating contest at a Mardi Gras celebration, he noted, had consumed 6,000 calories and 375 grams of fat in 15 minutes. "Another vivid example of our toxic food environment," he said.

Dr. Davis and the former Nadine Messina were married in 1979 and had three sons, Jared, Evan, and Connor. In addition to his wife and sons, all of East Lansing, Mich., Dr. Davis leaves a brother, Gary, of Deerfield Beach, Fla.; three half-brothers, Dr. Joseph Golbus of Northbrook, Ill., Sergeant David Davis of Fort Buchanan, Puerto Rico, and David Komessar of Newton, Mass.; a sister, Lynne of Wendell, Mass.; and four half-sisters, Brenda Nyquist of Buffalo Grove, Ill., Abby Hirsh of Northbrook, Ill., Debra Magier of Newton, Mass., and Julie Godnik of Northbrook, Ill.