His studies showed that a B vitamin deficiency could cause hardened arteries. It took the medical profession more than a decade to catch up.
Kilmer S. McCully, a pathologist at Harvard Medical School in the 1960s and ’70s whose colleagues banished him to the basement for insisting — correctly, it turned out — that homocysteine, an amino acid, was being overlooked as a possible risk factor for heart disease, died on Feb. 21 at his home in Winchester, Mass. He was 91.
His daughter, Martha McCully, said the cause was metastatic prostate cancer. His death was not widely reported at the time.
Still a debated idea today, Dr. McCully’s theory — that inadequate intake of certain B vitamins causes high levels of homocysteine in the blood, hardening the arteries with plaque — challenged the cholesterol-focused paradigm backed by the pharmaceutical industry.
Dr. McCully didn’t think cholesterol should be ignored, but he thought it was malpractice to disregard the significance of homocysteine. His bosses at Harvard disagreed. First, they moved his lab below ground; then they told him to leave. He struggled to find work for years.
“It was very traumatic,” he told the New York Times medical reporter Gina Kolata in 1995. “People don’t believe you. They think you’re crazy.”
Dr. McCully, fashioning himself as a microbe hunter akin to Louis Pasteur, stumbled on homocysteine in the late 1960s at a medical conference in Boston. There he learned about homocystinuria, a genetic disease in which high amounts of homocysteine are found in the urine of some developmentally disabled children.