Late in his 80s, long after most contemporaries had set aside scientific inquiry, Dr. Alexander Leaf kept stopping by the laboratory to see if he could help researchers understand how fish oil might reduce heart attacks and increase longevity.
Such dedication surprised no one who knew him. As one of the first practicing physicians elected to the National Academy of Sciences, Dr. Leaf had carved a nearly singular path in the field of medicine.
“By any standards, Alex is an unusual man: a quiet person who rarely talks about himself or his achievements, but who has done more in his lifetime to exemplify the complete physician, educator, scientist, and world citizen than anyone I know,” Dr. Arnold S. Relman, former editor of the New England Journal of Medicine, wrote as an introduction in 1995 when the Association of American Physicians awarded the George M. Kober Medal, its highest honor, to Dr. Leaf.
His list of accomplishments was as varied as it was long. Early in his career, Dr. Leaf was a researcher in the field of kidney and electrolyte physiology. As chief of medicine at Massachusetts General Hospital, he established a primary care residency track before the idea became fashionable. He was among the first voices to suggest that exercise and diet could prevent or reverse heart disease. And in his 60s, he traveled to places as distant as the mountains of the Caucasus to study why some people live to advanced ages.
Dr. Leaf, who led the preventive medicine department at Harvard Medical School after stepping down as chief of medicine at MGH, died of pneumonia Dec. 24 in his Concord residence. He was 92, had formerly lived in Winchester for many years, and had been diagnosed with Parkinson’s disease.
“Alex was a great intellectual force,” said Dr. John Potts, who in 1981 succeeded Dr. Leaf as chief of medicine at MGH. “He saw matters very clearly and hewed to the most high standards of academic integrity and institutional commitment to public health.”
During his tenure as MGH’s chief of medicine, Dr. Leaf established satellite outpatient clinics in less affluent communities.
“Preventive medicine was his true touchstone,” Potts said. “He was worried that we spend too much money on expensive interventions late in life and too little on early preventive medicine in the larger community, where the individual cost was much lower, but the impact was much greater.”
Dr. Leaf “was one of the clearest-thinking people I ever saw,” said Dr. Samuel O. Thier, a former president of MGH and Brandeis University who also formerly was chief executive of Partners HealthCare.
“Alex stood out among all the major figures in Boston academic medicine for most of his career because of the range of his interests,” Relman, who also is a professor emeritus at Harvard Medical School, said in an interview. “In his time, if you asked people in Boston medicine, and around the country, to name the few most respected intellectual leaders of American medicine, Alex Leaf’s name would certainly be right up there at the top.”
Born Alexander Livshiz, Dr. Leaf was the younger of two sons of Russian dentists who fled to Yokohama, Japan, after the Bolshevik Revolution. Dr. Leaf was 2 when his family moved from Yokohama to Seattle, where his parents chose a different last name.
While in Seattle, he met Barbara Kincaid, and they married in 1943. Three years earlier, he graduated from the University of Washington with a degree in chemistry.
He went to medical school at the University of Michigan and came to Boston for a residency at Mass. General. After further studies at the Mayo Clinic in Minnesota, and working at a military hospital in El Paso, Dr. Leaf went back to the University of Michigan to conduct research.
He returned to MGH in 1949 on a research fellowship.
His research on membrane biophysics was “some of the best, most innovative work in the field,” Relman wrote in the award introduction, which was published in the January 1996 issue of the Proceedings of the Association of American Physicians. “He also was a fine teacher, sometimes taciturn and reticent before large audiences but at his best in smaller groups, where his delight in science and the honesty and lucidity of his thought were so evident,” Relman wrote.
At the beginning of 1966, Dr. Leaf became the Jackson professor of clinical medicine at Harvard Medical School and chairman of medical services at Mass. General, a post he held until 1981.
That year, he was appointed head of Harvard’s preventive medicine department.
In the years that followed, and after he became a professor emeritus in 1990, Dr. Leaf continued to study how diet and exercise affect cardiovascular disease.
His longevity studies, meanwhile, focused on people who lived in mountainous areas, subsisted on a diet rich in vegetables and low in animal fat, and worked outside late into life. While not everyone could aspire to such an existence, “it’s extremely important to show that without drugs, just by changing people’s lifestyle, you can get coronary artery disease to regress,” Dr. Leaf told The New York Times in 1988, responding to a study whose preliminary findings showed that a low-fat diet, exercise, and stress management could halt or reverse hardening of the arteries. “This is going to shake up physicians’ thinking.”
Services will be private for Dr. Leaf, who in addition to his wife leaves three daughters, Caroline of London, Rebecca of Nicaragua, and Tamara of Winchester; and two grandchildren.
Dr. Leaf “really was a paragon of integrity in all aspects of his life,” said Dr. Dennis Ausiello, chairman of the department of medicine at MGH, “and truly his commitment to the patient and academic mission really set the stage for future generations and what we now call the physician-scientist.”
Dr. Leaf could also remain unruffled in the face of change, as was the case when some people he studied during his longevity research turned out to be very old, but not past 100, as they originally claimed. He learned of the discrepancy when he did follow-up field work.
After one return trip to Azerbaijan, Thier recalled, “with classic Alex humor, he said: ‘I spoke to a fellow last year when he was 110. Now he’s 98, but nonetheless, these guys are in better shape than we are.’ ”
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