Kilmer S. McCully, the valiant pathologist who faced professional ostracism for his groundbreaking theory on heart disease, passed away on February 21 at the age of 91. His daughter, Martha McCully, confirmed that the cause of death was metastatic prostate cancer, although the news of his passing did not receive significant public attention.

Dr. McCully, who served at Harvard Medical School during the 1960s and 70s, proposed a revolutionary idea that contradicted the cholesterol-centric narrative embraced by mainstream medicine and pharmaceutical companies. He asserted that high levels of homocysteine, an amino acid, were a critical risk factor in heart disease—an insight that would later gain recognition as a pivotal piece in understanding cardiovascular health.

McCully's revelation stemmed from his research into homocystinuria, a genetic disorder leading to elevated homocysteine levels in urine among affected children. His discoveries began in earnest at a medical conference where he uncovered distressing case studies, including the tragic story of a 9-year-old girl and her uncle, both afflicted with the condition. His findings were shocking: the autopsy results showed hardened arteries with no cholesterol present, challenging the conventional wisdom of the time.

In 1969, Dr. McCully published a seminal paper outlining his findings, yet the response from the medical community was disheartening. He faced isolation, and his colleagues at Harvard moved his lab to the basement as a form of professional exile, ultimately leading to his departure from the institution.

“It was very traumatic,” he recounted in a 1995 interview, describing the disbelief and ridicule he faced from peers. Yet his resilience never wavered; he continued to advocate for more research into homocysteine and urged people to increase their intake of B vitamins, essential for keeping homocysteine levels in check.

The tide began to turn in the early 1990s when extensive studies, including data from the renowned Framingham Heart Study, began to validate McCully’s theories. Research indicated that elevated homocysteine levels were associated with a significantly higher risk of cardiovascular complications. This shift in scientific consensus marked a crucial vindication for Dr. McCully and helped reshape the understanding of heart disease risk factors.

Meir Stampfer, a Harvard epidemiologist, acknowledged McCully’s contributions: "He was right about homocysteine being a marker for cardiovascular disease risk." Through his relentless pursuit of truth, McCully not only triumphed personally but also enriched the field of cardiology.

Kilmer McCully’s academic journey began at Harvard, where he earned degrees in biochemistry and medicine, studying under influential figures like B.F. Skinner. He joined the Harvard pathology department in 1965 and spent his later years at a Veterans Affairs hospital in Providence, Rhode Island. His journey was deeply intertwined with his family life; he was married to Annina Jacobs, who predeceased him last year. He leaves behind two children, Martha and Michael, along with grandchildren, great-grandchildren, and a sister.

After years of marginalization, Dr. McCully’s return to the spotlight in the 1990s as a respected figure in medical discourse not only solidified his scientific legacy but also serves as a poignant reminder of the challenges faced by pioneers who dare to challenge the established norms. His life's work continues to resonate, helping shape guidelines for heart disease prevention and treatment to this day.